Pub Date : 2026-02-07DOI: 10.1016/j.plaphy.2026.111128
Bing Sun , Zhaoxia Dong , Feng Zhang , Zhixian Zhu , Cheng Zhang , Guangming Han , Cui Yu
Maintenance of winter bud dormancy is a critical agronomic trait determining the fruit ripening period in mulberry (Morus spp.); however, the underlying molecular regulatory mechanisms remain largely elusive. In this study, we utilized an F1 segregating population derived from a cross between the late-budding species Morus wittiorum and the early-budding cultivar ‘322'. By integrating bulked segregant analysis sequencing (BSA-Seq) with RNA-Seq, we identified a dormancy-associated quantitative trait locus (QTL) interval (LB, 9.99–11.99 Mb) on chromosome 13 and pinpointed MaBGA (a β-glucosidase gene) as a candidate gene. Functional characterization via virus-induced gene silencing (VIGS) demonstrated that MaSVP acts as a repressor of winter bud sprouting, whereas MaBGA facilitates dormancy release. Yeast one-hybrid, dual-luciferase reporter, and electrophoretic mobility shift assays (EMSA) further confirmed that MaSVP directly binds to the MaBGA promoter to repress its transcription. Consistently, MaBGA expression was significantly upregulated during bud sprouting. Here, we unveil a novel MaSVP-MaBGA regulatory module. Distinct from the classical model where SVP/DAM proteins regulate dormancy indirectly via hormone homeostasis, this module maintains winter bud dormancy through the direct molecular interaction between a transcription factor and a β-glucosidase gene, thereby expanding the molecular regulatory network of bud dormancy in perennial plants. These findings not only provide fresh insights into the dormancy mechanisms of mulberry but also offer critical genetic resources and theoretical foundations for the molecular breeding of early- and late-ripening varieties.
{"title":"Molecular regulation of winter bud dormancy in mulberry (Morus spp.) through the MaSVP-MaBGA signaling module","authors":"Bing Sun , Zhaoxia Dong , Feng Zhang , Zhixian Zhu , Cheng Zhang , Guangming Han , Cui Yu","doi":"10.1016/j.plaphy.2026.111128","DOIUrl":"10.1016/j.plaphy.2026.111128","url":null,"abstract":"<div><div>Maintenance of winter bud dormancy is a critical agronomic trait determining the fruit ripening period in mulberry (<em>Morus</em> spp.); however, the underlying molecular regulatory mechanisms remain largely elusive. In this study, we utilized an F1 segregating population derived from a cross between the late-budding species <em>Morus wittiorum</em> and the early-budding cultivar ‘322'. By integrating bulked segregant analysis sequencing (BSA-Seq) with RNA-Seq, we identified a dormancy-associated quantitative trait locus (QTL) interval (LB, 9.99–11.99 Mb) on chromosome 13 and pinpointed <em>MaBGA</em> (a <em>β-glucosidase</em> gene) as a candidate gene. Functional characterization via virus-induced gene silencing (VIGS) demonstrated that <em>MaSVP</em> acts as a repressor of winter bud sprouting, whereas <em>MaBGA</em> facilitates dormancy release. Yeast one-hybrid, dual-luciferase reporter, and electrophoretic mobility shift assays (EMSA) further confirmed that MaSVP directly binds to the <em>MaBGA</em> promoter to repress its transcription. Consistently, <em>MaBGA</em> expression was significantly upregulated during bud sprouting. Here, we unveil a novel MaSVP-MaBGA regulatory module. Distinct from the classical model where SVP/DAM proteins regulate dormancy indirectly via hormone homeostasis, this module maintains winter bud dormancy through the direct molecular interaction between a transcription factor and a <em>β-glucosidase</em> gene, thereby expanding the molecular regulatory network of bud dormancy in perennial plants. These findings not only provide fresh insights into the dormancy mechanisms of mulberry but also offer critical genetic resources and theoretical foundations for the molecular breeding of early- and late-ripening varieties.</div></div>","PeriodicalId":20234,"journal":{"name":"Plant Physiology and Biochemistry","volume":"232 ","pages":"Article 111128"},"PeriodicalIF":5.7,"publicationDate":"2026-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146192720","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-07DOI: 10.1016/j.plaphy.2026.111129
Shunran Zhang, Zixian Yao, Jinhua He, Linna Wang, Xiaoyue Zhang, Yangang Lan, Yan Xiang
Carya illinoinensis was a crop with high value and was widely cultivated in China. Particularly under the increasingly severe soil salinization background, the promotion of salt-tolerant C. illinoinensis varieties provided substantial economic benefits to local regions. However, the molecular mechanisms underlying C. illinoinensis's salt response remained unclear. Two-year-old C. illinoinensis saplings exhibited significant damage after treatment with 600 mM NaCl solution. Transcriptome data at nine salt treatment time points were obtained from two-year-old C. illinoinensis saplings using RNA-seq, and 7840 differentially expressed genes (DEGs) were identified to construct a time-ordered gene co-expression network (TO-GCN). DEGs in the TO-GCN were classified into 10 levels corresponding to salt treatment time points. Genes in Level 1 (L1) and Level 2 (L2) were enriched in Gene Ontology (GO) terms associated with photosynthesis and transport channel proteins. Cluster analysis identified three aquaporin-coding genes among highly expressed genes. Based on promoter cis-acting elements, A/T-rich sequence features, and antagonistic gene expression patterns in transcriptomic data, it was speculated that CiPIP2;8 might be transcriptionally repressed by the upstream transcription factor CiPLATZ23. This hypothesis was validated through a Dual-luciferase reporter (DLR) assay. The presence of ABA-responsive elements (ABREs) in ProCiPLATZ23 suggested its involvement in the abscisic acid (ABA) pathway. Transient expression of ProCiPLATZ23::GUS in Nicotiana benthamiana exhibited enhanced histochemical staining following ABA treatment. Within 24 h after spraying walnuts with ABA, the transcription level of CiPLATZ23 rapidly increased. Furthermore, 35S::CiPLATZ23 overexpression lines in Arabidopsis thaliana displayed reduced ABA sensitivity compared to Wild-type (WT) A. thaliana. Reverse transcription quantitative PCR (RT-qPCR), yeast one-hybrid, and DLR assays confirmed that CiPLATZ23 participated in regulating ABA sensitivity by binding to the promoter of AtPIP2;8, the homolog of CiPIP2;8 in A. thaliana. Characterization of canonical ABA pathway families confirmed that C. illinoinensis ABA responses were implicated under salt stress. This study employed TO-GCN analysis of RNA-seq data to elucidate salt stress response mechanisms in C. illinoinensis and identified a key module 'CiPLATZ23-PIP2; 8′ that may be associated with ABA.
{"title":"TO-GCN analysis reveals the salt response mechanism in Carya illinoinensis and a Preliminary Exploration of the ‘CiPLATZ23-PIP2;8’ module","authors":"Shunran Zhang, Zixian Yao, Jinhua He, Linna Wang, Xiaoyue Zhang, Yangang Lan, Yan Xiang","doi":"10.1016/j.plaphy.2026.111129","DOIUrl":"10.1016/j.plaphy.2026.111129","url":null,"abstract":"<div><div><em>Carya illinoinensis</em> was a crop with high value and was widely cultivated in China. Particularly under the increasingly severe soil salinization background, the promotion of salt-tolerant <em>C</em>. <em>illinoinensis</em> varieties provided substantial economic benefits to local regions. However, the molecular mechanisms underlying <em>C</em>. <em>illinoinensis</em>'s salt response remained unclear. Two-year-old <em>C</em>. <em>illinoinensis</em> saplings exhibited significant damage after treatment with 600 mM NaCl solution. Transcriptome data at nine salt treatment time points were obtained from two-year-old <em>C</em>. <em>illinoinensis</em> saplings using RNA-seq, and 7840 differentially expressed genes (DEGs) were identified to construct a time-ordered gene co-expression network (TO-GCN). DEGs in the TO-GCN were classified into 10 levels corresponding to salt treatment time points. Genes in Level 1 (L1) and Level 2 (L2) were enriched in Gene Ontology (GO) terms associated with photosynthesis and transport channel proteins. Cluster analysis identified three aquaporin-coding genes among highly expressed genes. Based on promoter cis-acting elements, A/T-rich sequence features, and antagonistic gene expression patterns in transcriptomic data, it was speculated that <em>CiPIP2;</em>8 might be transcriptionally repressed by the upstream transcription factor CiPLATZ23. This hypothesis was validated through a Dual-luciferase reporter (DLR) assay. The presence of ABA-responsive elements (ABREs) in Pro<em>CiPLATZ23</em> suggested its involvement in the abscisic acid (ABA) pathway. Transient expression of <em>ProCiPLATZ23::GUS</em> in <em>Nicotiana benthamiana</em> exhibited enhanced histochemical staining following ABA treatment. Within 24 h after spraying walnuts with ABA, the transcription level of <em>CiPLATZ23</em> rapidly increased. Furthermore, <em>35S::CiPLATZ23</em> overexpression lines in <em>Arabidopsis thaliana</em> displayed reduced ABA sensitivity compared to Wild-type (WT) <em>A</em>. <em>thaliana</em>. Reverse transcription quantitative PCR (RT-qPCR), yeast one-hybrid, and DLR assays confirmed that CiPLATZ23 participated in regulating ABA sensitivity by binding to the promoter of <em>AtPIP2;8</em>, the homolog of <em>CiPIP2;8</em> in <em>A</em>. <em>thaliana</em>. Characterization of canonical ABA pathway families confirmed that <em>C</em>. <em>illinoinensis</em> ABA responses were implicated under salt stress. This study employed TO-GCN analysis of RNA-seq data to elucidate salt stress response mechanisms in <em>C. illinoinensis</em> and identified a key module 'CiPLATZ23-PIP2; 8′ that may be associated with ABA.</div></div>","PeriodicalId":20234,"journal":{"name":"Plant Physiology and Biochemistry","volume":"232 ","pages":"Article 111129"},"PeriodicalIF":5.7,"publicationDate":"2026-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146192841","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-06DOI: 10.1016/j.plaphy.2026.111123
Mateus Simionato da Silva , Luciano Carlos da Maia , Bruna Miranda Rodrigues , Vera Quecini , Antonio Costa de Oliveira , Camila Pegoraro
Oats (Avena sativa L.) are generally considered tolerant to unfavorable environmental conditions, although drought is known to impose yield losses. Several breeding programs worldwide aim at producing new oat genotypes tolerant to water deficit, but the molecular mechanisms underlying drought responses remain scarcely characterized. We investigated the growth and biomass production of 12 oat genotypes submitted to dehydration induced by PEG. Shoot elongation and biomass production were severely impaired by osmotic stress, whereas in roots growth and dry weight were mostly increased. To gain further insight into the responses, seedlings from ‘URS Altiva’ were subjected to osmotic stress for seven days, their growth and biomass performance investigated, and the transcriptome was determined for the shoots and roots of control and water-stressed plants. Distinct transcriptional programs were demonstrated to control dehydration responses in shoots and roots, agreeing with the phenotypic responses. Photosynthesis and chloroplast assembly pathways were negatively affected in the shoots, whereas in the roots the transcription of defense genes was mostly impaired. The salvage pathways induced by osmotic stress in oat shoots and roots were shared, consisting of water deprivation and abscisic acid-mediated pathways. Candidate genes and transcription factors regulating these pathways in response to dehydration were identified. Three modules of co-regulated genes were demonstrated to be correlated with biomass production in the shoots and roots and shoot elongation. This work contributes to the current understanding of the molecular mechanisms underlying the differential response of shoots and roots to dehydration and may provide tools to develop new tolerant cultivars.
{"title":"Distinct transcriptional programs control polyethylene glycol (PEG)-induced drought stress responses in oat (Avena sativa L.) shoot and roots","authors":"Mateus Simionato da Silva , Luciano Carlos da Maia , Bruna Miranda Rodrigues , Vera Quecini , Antonio Costa de Oliveira , Camila Pegoraro","doi":"10.1016/j.plaphy.2026.111123","DOIUrl":"10.1016/j.plaphy.2026.111123","url":null,"abstract":"<div><div>Oats (<em>Avena sativa</em> L.) are generally considered tolerant to unfavorable environmental conditions, although drought is known to impose yield losses. Several breeding programs worldwide aim at producing new oat genotypes tolerant to water deficit, but the molecular mechanisms underlying drought responses remain scarcely characterized. We investigated the growth and biomass production of 12 oat genotypes submitted to dehydration induced by PEG. Shoot elongation and biomass production were severely impaired by osmotic stress, whereas in roots growth and dry weight were mostly increased. To gain further insight into the responses, seedlings from ‘URS Altiva’ were subjected to osmotic stress for seven days, their growth and biomass performance investigated, and the transcriptome was determined for the shoots and roots of control and water-stressed plants. Distinct transcriptional programs were demonstrated to control dehydration responses in shoots and roots, agreeing with the phenotypic responses. Photosynthesis and chloroplast assembly pathways were negatively affected in the shoots, whereas in the roots the transcription of defense genes was mostly impaired. The salvage pathways induced by osmotic stress in oat shoots and roots were shared, consisting of water deprivation and abscisic acid-mediated pathways. Candidate genes and transcription factors regulating these pathways in response to dehydration were identified. Three modules of co-regulated genes were demonstrated to be correlated with biomass production in the shoots and roots and shoot elongation. This work contributes to the current understanding of the molecular mechanisms underlying the differential response of shoots and roots to dehydration and may provide tools to develop new tolerant cultivars.</div></div>","PeriodicalId":20234,"journal":{"name":"Plant Physiology and Biochemistry","volume":"232 ","pages":"Article 111123"},"PeriodicalIF":5.7,"publicationDate":"2026-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146158135","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-06DOI: 10.1016/j.plaphy.2026.111103
Bayu Pradana Nur Rahmat , Iqbal Fathurrahim Elfakhriano , Nono Carsono , Farida Damayanti , Syariful Mubarok , Hoshikawa Ken , Hiroshi Ezura , Seung Won Kang
Heat stress during seed germination represents a critical constraint to crop establishment, yet the hormonal and genetic mechanisms governing seed resilience to heat stress remains poorly understood. In tomato (Solanum lycopersicum), the role of auxin signaling repressor SlIAA9 in regulating seed germination and responses to heat stress has not been defined. Here, we investigated how loss of function mutation in SlIAA9 affects seed resilience under high temperature and post stress recovery. Utilizing two SlIAA9 mutant lines (iaa9-5 and iaa9-3) and Wild-Type Micro-Tom tomatoes, we assessed germination behaviors, seed quality parameters, reactive oxygen species (ROS) contents, and transcriptional responses during heat stress and recovery. Both mutants exhibited enhanced resilience to heat stress, with iaa9-5 maintaining high germination rate, normal seed and seedling qualities, and rapid post-stress recovery. This phenotype was associated with reduced accumulation of H2O2 and O2− and elevated expression of antioxidant and heat-responsive genes. Heat stress triggered stronger induction of HSFA9 and HSP70 in the mutants, while dormancy associated abscisic acid (ABA) biosynthesis genes were suppressed and ethylene biosynthesis genes were upregulated during stress recovery. Together, these findings identify SlIAA9 as a negative regulator of seed resilience to heat stress and loss of SlIAA9 function enhances antioxidant capacity and heat-responsive transcriptional programs during germination and recovery. Highlighting SlIAA9 as a potential genetic target for improving seed resilience to heat stress.
{"title":"SlIAA9 mutation enhances tomato seed resilience to heat stress","authors":"Bayu Pradana Nur Rahmat , Iqbal Fathurrahim Elfakhriano , Nono Carsono , Farida Damayanti , Syariful Mubarok , Hoshikawa Ken , Hiroshi Ezura , Seung Won Kang","doi":"10.1016/j.plaphy.2026.111103","DOIUrl":"10.1016/j.plaphy.2026.111103","url":null,"abstract":"<div><div>Heat stress during seed germination represents a critical constraint to crop establishment, yet the hormonal and genetic mechanisms governing seed resilience to heat stress remains poorly understood. In tomato (<em>Solanum lycopersicum</em>), the role of auxin signaling repressor <em>SlIAA9</em> in regulating seed germination and responses to heat stress has not been defined. Here, we investigated how loss of function mutation in <em>SlIAA9</em> affects seed resilience under high temperature and post stress recovery. Utilizing two <em>SlIAA9</em> mutant lines (<em>iaa9-5 and iaa9-3</em>) and Wild-Type Micro-Tom tomatoes, we assessed germination behaviors, seed quality parameters, reactive oxygen species (ROS) contents, and transcriptional responses during heat stress and recovery. Both mutants exhibited enhanced resilience to heat stress, with <em>iaa9-5</em> maintaining high germination rate, normal seed and seedling qualities, and rapid post-stress recovery. This phenotype was associated with reduced accumulation of H<sub>2</sub>O<sub>2</sub> and O<sub>2</sub><sup>−</sup> and elevated expression of antioxidant and heat-responsive genes. Heat stress triggered stronger induction of <em>HSFA9</em> and <em>HSP70</em> in the mutants, while dormancy associated abscisic acid (ABA) biosynthesis genes were suppressed and ethylene biosynthesis genes were upregulated during stress recovery. Together, these findings identify <em>SlIAA9</em> as a negative regulator of seed resilience to heat stress and loss of <em>SlIAA9</em> function enhances antioxidant capacity and heat-responsive transcriptional programs during germination and recovery. Highlighting <em>SlIAA9</em> as a potential genetic target for improving seed resilience to heat stress.</div></div>","PeriodicalId":20234,"journal":{"name":"Plant Physiology and Biochemistry","volume":"232 ","pages":"Article 111103"},"PeriodicalIF":5.7,"publicationDate":"2026-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146192724","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Climate change, characterized by rising atmospheric CO2 and increasing drought stress, significantly affects plant growth and metabolism. Milk thistle (Silybum marianum), valued for its silymarin-rich seeds, is an important medicinal plant sensitive to these environmental changes. This study evaluated four genotypes—Hungary, Isfahan, Omidiyeh, and Charam—with three soil moisture levels (well-watered, moderate, and severe water deficit stress) in a factorial design with four replications under two distinct CO2 environments (ambient, 404 ± 24 μmol mol−1 CO2, and elevated, 702 ± 51 μmol mol−1 CO2) imposed using two fixed open-top chambers (OTCs). Elevated CO2 potentially enhanced growth and yield traits but was associated with declines in photosynthetic pigments and antioxidant enzyme activities. Genotype-specific responses were evident: Hungary and Isfahan showed the greatest seed weight, oil, and silymarin production under elevated CO2 and in well-watered and moderate drought conditions; Charam maintained higher chlorophyll a and shoot biomass particularly under severe drought stress; Omidiyeh accumulated the most root biomass and proline, aiding drought tolerance under combined elevated CO2 and severe drought stress. Drought stress increased total phenolics, flavonoids, and antioxidant activity but reduced oil content, silymarin yield, and photosystem II efficiency (Fv/Fm). Multivariate analysis highlighted Charam's ability to sustain leaf water content and flavonoid production, while Omidiyeh demonstrated stronger antioxidant defenses under combined elevated CO2 and drought. These genotype-specific adaptations reveal a growth-defense trade-off under elevated CO2 and drought, offering promising targets for breeding milk thistle varieties that balance biomass, medicinal compounds, and stress tolerance in a changing climate.
{"title":"Trade-offs between biomass and bioactive compounds in Silybum marianum under elevated CO2 and water deficit across genotypes","authors":"Shiba Samieadel, Hamid Reza Eshghizadeh, Morteza Zahedi, Mohammd Mahdi Majidi","doi":"10.1016/j.plaphy.2026.111047","DOIUrl":"10.1016/j.plaphy.2026.111047","url":null,"abstract":"<div><div>Climate change, characterized by rising atmospheric CO<sub>2</sub> and increasing drought stress, significantly affects plant growth and metabolism. Milk thistle (<em>Silybum marianum</em>), valued for its silymarin-rich seeds, is an important medicinal plant sensitive to these environmental changes. This study evaluated four genotypes—Hungary, Isfahan, Omidiyeh, and Charam—with three soil moisture levels (well-watered, moderate, and severe water deficit stress) in a factorial design with four replications under two distinct CO<sub>2</sub> environments (ambient, 404 ± 24 μmol mol<sup>−1</sup> CO<sub>2</sub>, and elevated, 702 ± 51 μmol mol<sup>−1</sup> CO<sub>2</sub>) imposed using two fixed open-top chambers (OTCs). Elevated CO<sub>2</sub> potentially enhanced growth and yield traits but was associated with declines in photosynthetic pigments and antioxidant enzyme activities. Genotype-specific responses were evident: Hungary and Isfahan showed the greatest seed weight, oil, and silymarin production under elevated CO<sub>2</sub> and in well-watered and moderate drought conditions; Charam maintained higher <em>chlorophyll a</em> and shoot biomass particularly under severe drought stress; Omidiyeh accumulated the most root biomass and proline, aiding drought tolerance under combined elevated CO<sub>2</sub> and severe drought stress. Drought stress increased total phenolics, flavonoids, and antioxidant activity but reduced oil content, silymarin yield, and photosystem II efficiency (<em>Fv/Fm</em>). Multivariate analysis highlighted Charam's ability to sustain leaf water content and flavonoid production, while Omidiyeh demonstrated stronger antioxidant defenses under combined elevated CO<sub>2</sub> and drought. These genotype-specific adaptations reveal a growth-defense trade-off under elevated CO<sub>2</sub> and drought, offering promising targets for breeding milk thistle varieties that balance biomass, medicinal compounds, and stress tolerance in a changing climate.</div></div>","PeriodicalId":20234,"journal":{"name":"Plant Physiology and Biochemistry","volume":"232 ","pages":"Article 111047"},"PeriodicalIF":5.7,"publicationDate":"2026-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146192725","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Drought stress is a major constraint on the productivity of temperate forage grasses such as perennial ryegrass (Lolium perenne). While nitrogen management is widely employed in agronomic practice, its specific role in mediating drought adaptation strategies remains unclear. This study aimed to systematically characterize the response of perennial ryegrass to drought stress following low nitrogen pre-acclimation through integrated physiological and transcriptomic analyses during both stress and recovery phases. Our results demonstrated that drought severely impaired photosynthetic capacity and induced oxidative damage in non-acclimated plants, as evidenced by the significant reductions in net photosynthetic rate, stomatal conductance and PSII efficiency (Fv/Fm), alongside elevated malondialdehyde (MDA) levels and increased activities of key antioxidant enzymes (e.g., ascorbate peroxidase, peroxidase and catalase). In contrast, low nitrogen pre-acclimation effectively preserved photosynthetic performance under subsequent drought, mitigating declines in gas exchange parameters and maintaining PSII integrity. These pre-acclimated plants also exhibited reduced oxidative stress under drought and superior recovery capacity after rewatering. This enhanced drought tolerance was associated with fructan accumulation and tempered transcriptional responses. Low nitrogen pre-acclimation mitigated the drought-induced transcriptional upheaval, attenuated the activation of hormonal signaling pathways and MAPK cascades, significantly alleviated the downregulation of genes encoding photosynthetic apparatus, stabilized chlorophyll metabolism and optimized carbon-nitrogen balance. These findings reveal a nitrogen-mediated priming mechanism that enhances drought tolerance through integrated metabolic and transcriptional adjustments, providing new insights into the interaction between nutrient signaling and stress resistance, as well as potential strategies for enhancing plant tolerance under climate change.
{"title":"Pre-acclimation to low nitrogen enhances drought tolerance in Lolium perenne through integrated metabolic and transcriptional alterations","authors":"Hui Zuo , Xinyue Xiong , Yuqian Chen, Qianqian Guo","doi":"10.1016/j.plaphy.2026.111109","DOIUrl":"10.1016/j.plaphy.2026.111109","url":null,"abstract":"<div><div>Drought stress is a major constraint on the productivity of temperate forage grasses such as perennial ryegrass (<em>Lolium perenne</em>). While nitrogen management is widely employed in agronomic practice, its specific role in mediating drought adaptation strategies remains unclear. This study aimed to systematically characterize the response of perennial ryegrass to drought stress following low nitrogen pre-acclimation through integrated physiological and transcriptomic analyses during both stress and recovery phases. Our results demonstrated that drought severely impaired photosynthetic capacity and induced oxidative damage in non-acclimated plants, as evidenced by the significant reductions in net photosynthetic rate, stomatal conductance and PSII efficiency (<em>Fv</em>/<em>Fm</em>), alongside elevated malondialdehyde (MDA) levels and increased activities of key antioxidant enzymes (e.g., ascorbate peroxidase, peroxidase and catalase). In contrast, low nitrogen pre-acclimation effectively preserved photosynthetic performance under subsequent drought, mitigating declines in gas exchange parameters and maintaining PSII integrity. These pre-acclimated plants also exhibited reduced oxidative stress under drought and superior recovery capacity after rewatering. This enhanced drought tolerance was associated with fructan accumulation and tempered transcriptional responses. Low nitrogen pre-acclimation mitigated the drought-induced transcriptional upheaval, attenuated the activation of hormonal signaling pathways and <em>MAPK</em> cascades, significantly alleviated the downregulation of genes encoding photosynthetic apparatus, stabilized chlorophyll metabolism and optimized carbon-nitrogen balance. These findings reveal a nitrogen-mediated priming mechanism that enhances drought tolerance through integrated metabolic and transcriptional adjustments, providing new insights into the interaction between nutrient signaling and stress resistance, as well as potential strategies for enhancing plant tolerance under climate change.</div></div>","PeriodicalId":20234,"journal":{"name":"Plant Physiology and Biochemistry","volume":"232 ","pages":"Article 111109"},"PeriodicalIF":5.7,"publicationDate":"2026-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146143364","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-06DOI: 10.1016/j.plaphy.2026.111099
Wenbing Zhao , Zhongxing Zhang , Yanlong Gao , Xulin Xian , Donghai Zhang , Juanli Li , Xiaoling Li , Wentai Sun , Yanxiu Wang
DEAD-box helicases represent the largest subfamily of RNA helicases and play a crucial role in plant stress responses. Based on the whole genome of apple, 134 members of the DEAD-box family (designated as MdRH1 to MdRH134) was identified. These members exhibit significant differences in protein physicochemical properties, which are unevenly distributed across 17 chromosomes, with segmental duplication being the main expansion mechanism. Additionally, the promoter regions of these family genes are rich in cis-elements related to hormones, stresses, and growth. Real-time fluorescence quantification-polymerase chain reaction (RT-qPCR) revealed that MdRH28 is significantly upregulated under low temperature (4 °C). To clarify its function, the MdRH28 gene was cloned and stably transformed into apple calli and transiently transformed into Malus hupehensis. After 4 °C low-temperature treatment, compared with the WT lines, the overexpression lines of MdRH28 exhibited a significantly better growth status in apple calli. The specific manifestations were as follows: higher fresh weight; lower accumulation of malondialdehyde (MDA), relative electrical conductivity (REC), and reactive oxygen species (ROS, including H2O2 and O2−); higher proline content and higher activities of antioxidant enzymes such as superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT); The content of abscisic acid (ABA) increased, while the contents of growth-related hormones such as indole-3-acetic acid (IAA), gibberellin A3 (GA3), and zeatin (ZT) decreased. Meanwhile, the expression of low-temperature response genes (CBF1/2/3, COR47, and NCED1) was upregulated. In contrast, the antisense and gene-silencing lines showed the opposite trends. Specifically, the silencing MdRH28 lines through virus-induced gene silencing (VIGS) exhibited severe wilting; the levels of REC, MDA, and ROS in their leaves increased; the chlorophyll content, net photosynthetic rate (Pn), and maximum photochemical efficiency of photosystem Ⅱ (Fv/Fm) decreased more significantly; and the expression of cold-resistant genes was downregulated. In conclusion, MdRH28 significantly enhances the low-temperature tolerance by alleviating low-temperature-induced osmotic and oxidative damage, regulating the balance of endogenous hormones, and activating genes in the low-temperature response pathway. This study provides important genetic resources and a theoretical basis for cold-resistant apple breeding.
{"title":"Identification of the DEAD-box gene family in apple (Malus domestica) and functional verification of MdRH28 under low-temperature stress","authors":"Wenbing Zhao , Zhongxing Zhang , Yanlong Gao , Xulin Xian , Donghai Zhang , Juanli Li , Xiaoling Li , Wentai Sun , Yanxiu Wang","doi":"10.1016/j.plaphy.2026.111099","DOIUrl":"10.1016/j.plaphy.2026.111099","url":null,"abstract":"<div><div>DEAD-box helicases represent the largest subfamily of RNA helicases and play a crucial role in plant stress responses. Based on the whole genome of apple, 134 members of the DEAD-box family (designated as <em>MdRH1</em> to <em>MdRH134</em>) was identified. These members exhibit significant differences in protein physicochemical properties, which are unevenly distributed across 17 chromosomes, with segmental duplication being the main expansion mechanism. Additionally, the promoter regions of these family genes are rich in cis-elements related to hormones, stresses, and growth. Real-time fluorescence quantification-polymerase chain reaction (RT-qPCR) revealed that <em>MdRH28</em> is significantly upregulated under low temperature (4 °C). To clarify its function, the <em>MdRH28</em> gene was cloned and stably transformed into apple calli and transiently transformed into <em>Malus hupehensis</em>. After 4 °C low-temperature treatment, compared with the WT lines, the overexpression lines of <em>MdRH28</em> exhibited a significantly better growth status in apple calli. The specific manifestations were as follows: higher fresh weight; lower accumulation of malondialdehyde (MDA), relative electrical conductivity (REC), and reactive oxygen species (ROS, including H<sub>2</sub>O<sub>2</sub> and O<sub>2</sub><sup>−</sup>); higher proline content and higher activities of antioxidant enzymes such as superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT); The content of abscisic acid (ABA) increased, while the contents of growth-related hormones such as indole-3-acetic acid (IAA), gibberellin A<sub>3</sub> (GA<sub>3</sub>), and zeatin (ZT) decreased. Meanwhile, the expression of low-temperature response genes (<em>CBF1/2/3</em>, <em>COR47</em>, and <em>NCED1</em>) was upregulated. In contrast, the antisense and gene-silencing lines showed the opposite trends. Specifically, the silencing <em>MdRH28</em> lines through virus-induced gene silencing (VIGS) exhibited severe wilting; the levels of REC, MDA, and ROS in their leaves increased; the chlorophyll content, net photosynthetic rate (Pn), and maximum photochemical efficiency of photosystem Ⅱ (Fv/Fm) decreased more significantly; and the expression of cold-resistant genes was downregulated. In conclusion, <em>MdRH28</em> significantly enhances the low-temperature tolerance by alleviating low-temperature-induced osmotic and oxidative damage, regulating the balance of endogenous hormones, and activating genes in the low-temperature response pathway. This study provides important genetic resources and a theoretical basis for cold-resistant apple breeding.</div></div>","PeriodicalId":20234,"journal":{"name":"Plant Physiology and Biochemistry","volume":"232 ","pages":"Article 111099"},"PeriodicalIF":5.7,"publicationDate":"2026-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146192839","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-06DOI: 10.1016/j.plaphy.2026.111124
Maria Gracheva , Máté Sági-Kazár , Sophie Zoe Farkas , Barnabás Cseh , Szilamér Koszti , Valentina Bonanni , Milan Žižić , Enkhjin Enkhbileg , Katarina Vogel-Mikuš , László Péter , Katalin Solymosi , Krisztina Kovács , Alessandra Gianoncelli , Ádám Solti
Chloroplasts require a significant amount of iron to build up the photosynthetic apparatus. Upon developmental senescence, chloroplasts iron is subjected to remobilisation. Processes that enable iron removal from the chloroplasts have not been clarified in detail yet. Ferritins are primary iron storage proteins. Although chloroplast ferritins accumulate, in part during leaf senescence, their role in the removal of chloroplast iron has not been revealed in detail yet. Using Arabidopsis thaliana Col-0 model, we have studied the accumulation and the form of iron at the initiation and the progressing of senescence. Senescence status was characterised by the expression of Oresara 1 and Senescence Associated Gene 12. Physiological parameters, iron content and localization together with transcript abundance information were collected from the same leaf individuals. At senescence initiation, the accumulation of iron in the chloroplasts together with Ferritin transcripts and (apo)proteins rose, whereas under progressing senescence, chloroplast iron accumulation decreased. Low-energy X-ray fluorescence microscopy confirmed this increase in the iron signal at chloroplast sites. Ferritin signal in 57Fe Mössbauer spectra (indicator of the major iron species population) was absent. Together with the stochastic presence of ferritin particles in chloroplasts this suggest that iron accumulation is a transient event involved in the iron remobilisation. Thus, ferritins do not serve as permanent storages, rather carriers that deliver iron for recycling during developmental senescence.
{"title":"Ferritin-mediated transient iron sequestration facilitates chloroplast iron recycling during leaf senescence","authors":"Maria Gracheva , Máté Sági-Kazár , Sophie Zoe Farkas , Barnabás Cseh , Szilamér Koszti , Valentina Bonanni , Milan Žižić , Enkhjin Enkhbileg , Katarina Vogel-Mikuš , László Péter , Katalin Solymosi , Krisztina Kovács , Alessandra Gianoncelli , Ádám Solti","doi":"10.1016/j.plaphy.2026.111124","DOIUrl":"10.1016/j.plaphy.2026.111124","url":null,"abstract":"<div><div>Chloroplasts require a significant amount of iron to build up the photosynthetic apparatus. Upon developmental senescence, chloroplasts iron is subjected to remobilisation. Processes that enable iron removal from the chloroplasts have not been clarified in detail yet. Ferritins are primary iron storage proteins. Although chloroplast ferritins accumulate, in part during leaf senescence, their role in the removal of chloroplast iron has not been revealed in detail yet. Using <em>Arabidopsis thaliana</em> Col-0 model, we have studied the accumulation and the form of iron at the initiation and the progressing of senescence. Senescence status was characterised by the expression of <em>Oresara 1</em> and <em>Senescence Associated Gene 12</em>. Physiological parameters, iron content and localization together with transcript abundance information were collected from the same leaf individuals. At senescence initiation, the accumulation of iron in the chloroplasts together with Ferritin transcripts and (apo)proteins rose, whereas under progressing senescence, chloroplast iron accumulation decreased. Low-energy X-ray fluorescence microscopy confirmed this increase in the iron signal at chloroplast sites. Ferritin signal in <sup>57</sup>Fe Mössbauer spectra (indicator of the major iron species population) was absent. Together with the stochastic presence of ferritin particles in chloroplasts this suggest that iron accumulation is a transient event involved in the iron remobilisation. Thus, ferritins do not serve as permanent storages, rather carriers that deliver iron for recycling during developmental senescence.</div></div>","PeriodicalId":20234,"journal":{"name":"Plant Physiology and Biochemistry","volume":"232 ","pages":"Article 111124"},"PeriodicalIF":5.7,"publicationDate":"2026-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146158159","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-05DOI: 10.1016/j.plaphy.2026.111108
Zhengjie Ji , Huihui Liu , Tobias Pöhnl , Susanne Neugart
This study provides a direct comparison of UV-B radiation (0.5 kJ m−2 d−1) and low temperature (10/12 °C) on secondary metabolites and enzyme activities in kale and pak choi, assessing both carotenoids and phenolics and including Arabidopsis wild type and uvr8 mutant under identical conditions for mechanistic validation. UV-B induced rapid accumulation of lutein, β-carotene, chlorophyll a, chlorophyll b and kaempferol glycosides in kale, while in pak choi, long-term low temperature or UV-B treatments (3–5 days) triggered similar responses. Notably, combined stress triggered synergistic accumulation of specific phenolic compounds in both species. Low temperature increased antioxidant activity and UV-B enhanced the activities of phenylalanine ammonia-lyase and peroxidase in both species; however, the interactive effects differed between species. Arabidopsis validation demonstrated the regulatory role of the UVR8 photoreceptor in mediating antioxidant responses and secondary metabolism under UV-B and low temperature. Taken together, exposure to UV-B radiation and low temperature according to species-specific responses could be a biotechnological tool to optimize the accumulation of bioactive compounds in Brassica vegetables, especially effective for vertical farming approaches.
{"title":"Interaction of preharvest UV-B and low temperature on antioxidant secondary plant metabolites in Brassica vegetables: A species-specific comparison of kale and pak choi","authors":"Zhengjie Ji , Huihui Liu , Tobias Pöhnl , Susanne Neugart","doi":"10.1016/j.plaphy.2026.111108","DOIUrl":"10.1016/j.plaphy.2026.111108","url":null,"abstract":"<div><div>This study provides a direct comparison of UV-B radiation (0.5 kJ m<sup>−2</sup> d<sup>−1</sup>) and low temperature (10/12 °C) on secondary metabolites and enzyme activities in kale and pak choi, assessing both carotenoids and phenolics and including <em>Arabidopsis</em> wild type and <em>uvr8 mutant</em> under identical conditions for mechanistic validation. UV-B induced rapid accumulation of lutein, <em>β</em>-carotene, chlorophyll <em>a</em>, chlorophyll <em>b</em> and kaempferol glycosides in kale, while in pak choi, long-term low temperature or UV-B treatments (3–5 days) triggered similar responses. Notably, combined stress triggered synergistic accumulation of specific phenolic compounds in both species. Low temperature increased antioxidant activity and UV-B enhanced the activities of phenylalanine ammonia-lyase and peroxidase in both species; however, the interactive effects differed between species. <em>Arabidopsis</em> validation demonstrated the regulatory role of the UVR8 photoreceptor in mediating antioxidant responses and secondary metabolism under UV-B and low temperature. Taken together, exposure to UV-B radiation and low temperature according to species-specific responses could be a biotechnological tool to optimize the accumulation of bioactive compounds in <em>Brassica</em> vegetables, especially effective for vertical farming approaches.</div></div>","PeriodicalId":20234,"journal":{"name":"Plant Physiology and Biochemistry","volume":"232 ","pages":"Article 111108"},"PeriodicalIF":5.7,"publicationDate":"2026-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146181826","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nitrogen (N) limitation significantly constrains crop growth, yield and quality. Developing crop varieties with high N deficiency tolerance represents a critical strategy for reducing N fertilizer application and promoting sustainable agriculture. Semi-wild soybean offers valuable genetic resources for the improvement of soybean varieties. Nevertheless, the mechanisms underlying N deficiency tolerance remain poorly understood. In this study, we employed a comprehensive analytical approach—including Pearson's correlation analysis, principal component analysis, subordinate function analysis, and cluster analysis—to evaluate the N starvation tolerance of 50 semi-wild soybean varieties. Shoot fresh weight, root-shoot ratio, SPAD2 value and leaf nitrate content were identified as key indicators for assessing N starvation tolerance. The variety V03 was identified as the most N starvation-tolerant. Comparative physiological analyses revealed that V03 enhances tolerance to N deficiency by optimizing root architecture and sustaining the activity of nitrogen metabolism enzymes—such as nitrate reductase (NR), glutamine synthetase (GS), glutamate synthase (GOGAT)—in root and leaf tissues. Transcriptomic analysis indicated that V03 exhibits a broader transcriptional response (with more N Starvation-induced DEGs) and functional reprogramming in root tissues, showing stronger enrichment in stress-responsive processes, regulatory functions, and plasma membrane-related terms as well as environmental information processing pathways. Furthermore, V03 displayed more pronounced changes in the expression of genes related to N transport, N assimilation and transcription factor (TF) compared to the N starvation-sensitive variety V46. This study provides a robust and comprehensive methodology for evaluating N deficiency tolerance in semi-wild soybean. Our findings offer new insights into the physiological adaptions and molecular regulatory network governing N uptake and metabolism, which may support future breeding efforts aimed at enhancing NUE in leguminous crops.
{"title":"Comprehensive evaluation, morpho-physiological and transcriptional response involving the tolerance of Semi-wild soybean (Glycine gracilis) seedlings to nitrogen starvation","authors":"Siqi Hou , Shixi Lu , Yuechuan Hou , Chunxiao Yu , Jiarui Zhang , Jichao Li , Chunmei Zong , Shuzhen Zhang , Xiaodong Ding , Jialei Xiao , Qiang Li","doi":"10.1016/j.plaphy.2026.111120","DOIUrl":"10.1016/j.plaphy.2026.111120","url":null,"abstract":"<div><div>Nitrogen (N) limitation significantly constrains crop growth, yield and quality. Developing crop varieties with high N deficiency tolerance represents a critical strategy for reducing N fertilizer application and promoting sustainable agriculture. Semi-wild soybean offers valuable genetic resources for the improvement of soybean varieties. Nevertheless, the mechanisms underlying N deficiency tolerance remain poorly understood. In this study, we employed a comprehensive analytical approach—including Pearson's correlation analysis, principal component analysis, subordinate function analysis, and cluster analysis—to evaluate the N starvation tolerance of 50 semi-wild soybean varieties. Shoot fresh weight, root-shoot ratio, SPAD2 value and leaf nitrate content were identified as key indicators for assessing N starvation tolerance. The variety V03 was identified as the most N starvation-tolerant. Comparative physiological analyses revealed that V03 enhances tolerance to N deficiency by optimizing root architecture and sustaining the activity of nitrogen metabolism enzymes—such as nitrate reductase (NR), glutamine synthetase (GS), glutamate synthase (GOGAT)—in root and leaf tissues. Transcriptomic analysis indicated that V03 exhibits a broader transcriptional response (with more N Starvation-induced DEGs) and functional reprogramming in root tissues, showing stronger enrichment in stress-responsive processes, regulatory functions, and plasma membrane-related terms as well as environmental information processing pathways. Furthermore, V03 displayed more pronounced changes in the expression of genes related to N transport, N assimilation and transcription factor (TF) compared to the N starvation-sensitive variety V46. This study provides a robust and comprehensive methodology for evaluating N deficiency tolerance in semi-wild soybean. Our findings offer new insights into the physiological adaptions and molecular regulatory network governing N uptake and metabolism, which may support future breeding efforts aimed at enhancing NUE in leguminous crops.</div></div>","PeriodicalId":20234,"journal":{"name":"Plant Physiology and Biochemistry","volume":"232 ","pages":"Article 111120"},"PeriodicalIF":5.7,"publicationDate":"2026-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146158200","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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