Beatrice L Harrison Day,Christopher McCarthy,Timothy J Brodribb,Madeline Carins-Murphy,Craig R Brodersen
Fine roots regulate plant water uptake, but the dynamic cell-level hydraulic behaviour of these organs remains poorly understood, particularly at the onset of drought. We investigated changes in fine root (<2 mm diameter) shrinkage, turgor loss, cell layer viability and uptake during dehydration and rehydration in soybean (Glycine max)to identify critical physiological thresholds of water potentials experienced by plants exposed to experimental drought. Fine root diameter shrank by over 50% at the completion of drying, with 55.36% of this relative shrinkage occurring by -0.25 MPa, and most of that water volume loss was attributed to epidermal and cortex cells. Epidermal cells lost turgor at -0.5 MPa and cortex cells reached mortality by -1.0 MPa, prior to xylem embolism onset. Cells within the stele remained viable after cortex and epidermal mortality until -1.75 MPa, coinciding with the 50% loss of xylem conductivity through embolism (whole-plant P50). Drought recovery experiments revealed that cortical and epidermal cell mortality slowed but did not prevent rehydration of those same cell layers, or whole plant rehydration, prior to embolism. The rapid, dynamic changes in cortical and epidermal cells during the earliest stages of drought exposure, and subsequent recovery, likely act to physically decouple fine roots from the surrounding soil to limit plant dehydration; an effect likely accelerated by bare-root lab drying conditions. Movement of water through these dead cell layers allows rehydration of living stele tissue prior to embolism, supporting root growth and recovery post-drought.
{"title":"Cortex death precedes stele failure in soybean fine roots during drought but does not prevent plant rehydration.","authors":"Beatrice L Harrison Day,Christopher McCarthy,Timothy J Brodribb,Madeline Carins-Murphy,Craig R Brodersen","doi":"10.1093/plphys/kiag132","DOIUrl":"https://doi.org/10.1093/plphys/kiag132","url":null,"abstract":"Fine roots regulate plant water uptake, but the dynamic cell-level hydraulic behaviour of these organs remains poorly understood, particularly at the onset of drought. We investigated changes in fine root (<2 mm diameter) shrinkage, turgor loss, cell layer viability and uptake during dehydration and rehydration in soybean (Glycine max)to identify critical physiological thresholds of water potentials experienced by plants exposed to experimental drought. Fine root diameter shrank by over 50% at the completion of drying, with 55.36% of this relative shrinkage occurring by -0.25 MPa, and most of that water volume loss was attributed to epidermal and cortex cells. Epidermal cells lost turgor at -0.5 MPa and cortex cells reached mortality by -1.0 MPa, prior to xylem embolism onset. Cells within the stele remained viable after cortex and epidermal mortality until -1.75 MPa, coinciding with the 50% loss of xylem conductivity through embolism (whole-plant P50). Drought recovery experiments revealed that cortical and epidermal cell mortality slowed but did not prevent rehydration of those same cell layers, or whole plant rehydration, prior to embolism. The rapid, dynamic changes in cortical and epidermal cells during the earliest stages of drought exposure, and subsequent recovery, likely act to physically decouple fine roots from the surrounding soil to limit plant dehydration; an effect likely accelerated by bare-root lab drying conditions. Movement of water through these dead cell layers allows rehydration of living stele tissue prior to embolism, supporting root growth and recovery post-drought.","PeriodicalId":20101,"journal":{"name":"Plant Physiology","volume":"9 1","pages":""},"PeriodicalIF":7.4,"publicationDate":"2026-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147446854","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Feng Zhang, Hailei Zhang, Pengxi Wang, Yinyao Qi, Huankai Li, Lin Zhu, Gefei Huang, Yiji Xia, Zongwei Cai
Nicotinamide adenine dinucleotide (NAD+) is a crucial cofactor in cyanobacteria, which serve as model organisms for studying photosynthesis. Maintaining NAD+ homeostasis in cyanobacteria is critically important, and it is currently believed that multiple pathways contribute to NAD+ biosynthesis in these organisms. However, the specific contribution of each pathway to NAD+ supplementation under both light and dark conditions, which determines NAD+ homeostasis, has not yet been studied. In this study, we identified NMNAT-C, a cyanobacterial nicotinamide nucleotide adenylyltransferase (NMNAT), as a key player in NAD+ homeostasis, particularly during dark phases. NMNAT-C showed opposite-phase oscillations in expression, aligned with NAD+ fluctuations during light-dark cycles. Genetic and biochemical tests revealed that deleting NMNAT-C in one cyanobacterium (Synechococcus elongatus PCC 7942) accelerated NAD+ depletion during dark periods, increased sensitivity to dark stress, and impacted growth rate. Conversely, induced overexpression of NMNAT-C temporarily raised NAD+ levels but also caused adverse effects over time. Metabolomic analysis indicated that NMNAT-C plays a role in mediating the metabolic crosstalk between the NAD+ salvage pathway and the de novo pathway. Our results identify NMNAT-C as a key regulator of NAD+ dynamics that aligns with daily cycles and suggest that this enzyme plays a crucial role in maintaining NAD+ homeostasis through the NAD+ salvage pathway.
{"title":"The NAD salvage pathway enzyme NMNAT-C sustains dark-phase NAD+ homeostasis in cyanobacteria","authors":"Feng Zhang, Hailei Zhang, Pengxi Wang, Yinyao Qi, Huankai Li, Lin Zhu, Gefei Huang, Yiji Xia, Zongwei Cai","doi":"10.1093/plphys/kiag143","DOIUrl":"https://doi.org/10.1093/plphys/kiag143","url":null,"abstract":"Nicotinamide adenine dinucleotide (NAD+) is a crucial cofactor in cyanobacteria, which serve as model organisms for studying photosynthesis. Maintaining NAD+ homeostasis in cyanobacteria is critically important, and it is currently believed that multiple pathways contribute to NAD+ biosynthesis in these organisms. However, the specific contribution of each pathway to NAD+ supplementation under both light and dark conditions, which determines NAD+ homeostasis, has not yet been studied. In this study, we identified NMNAT-C, a cyanobacterial nicotinamide nucleotide adenylyltransferase (NMNAT), as a key player in NAD+ homeostasis, particularly during dark phases. NMNAT-C showed opposite-phase oscillations in expression, aligned with NAD+ fluctuations during light-dark cycles. Genetic and biochemical tests revealed that deleting NMNAT-C in one cyanobacterium (Synechococcus elongatus PCC 7942) accelerated NAD+ depletion during dark periods, increased sensitivity to dark stress, and impacted growth rate. Conversely, induced overexpression of NMNAT-C temporarily raised NAD+ levels but also caused adverse effects over time. Metabolomic analysis indicated that NMNAT-C plays a role in mediating the metabolic crosstalk between the NAD+ salvage pathway and the de novo pathway. Our results identify NMNAT-C as a key regulator of NAD+ dynamics that aligns with daily cycles and suggest that this enzyme plays a crucial role in maintaining NAD+ homeostasis through the NAD+ salvage pathway.","PeriodicalId":20101,"journal":{"name":"Plant Physiology","volume":"95 1","pages":""},"PeriodicalIF":7.4,"publicationDate":"2026-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147465709","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Wallflower (Erysimum cheiri) belongs to the monogeneric Erysimeae tribe of the mustard family (Brassicaceae). It is widely cultivated as an ornamental garden plant and appreciated for its diverse flower colors. However, the absence of a high-quality genome has hampered research on wallflower genome evolution and the mechanisms underlying variations in flower color. Here, we assembled a nearly gap-free telomere-to-telomere genome of E. cheiri. The assembled genome enabled the reconstruction of genome evolution in the genus Erysimum (274 species), tracing the changes from the ancestral n = 8 genome (in E. cheiranthoides) to the derived genomes with seven (in E. nevadense) and six (in E. cheiri) chromosome pairs. While the reduction from n = 8 to n = 7 was mediated by a nested chromosome fusion accompanied by inversions, the further decrease to n = 6 in E. cheiri resulted from an end-to-end translocation involving the other two non-homologous chromosomes. Compared with other Brassicaceae species, E. cheiri showed a notable expansion of gene families related to secondary metabolite biosynthesis. Its flower color variation was primarily determined by the biosynthesis and accumulation of carotenoids and flavonoids. We mapped the metabolic pathways for carotenoids and flavonoids, identifying the hub genes regulating their biosynthesis. This research lays an important foundation for understanding the chromosomal and genome evolution of the Erysimeae tribe and paves the way for future investigations into genetic studies and breeding applications of E. cheiri.
{"title":"Insights into karyotype evolution and flower color variation from the genome assembly of wallflower (Erysimum cheiri).","authors":"Daozong Chen,Hui Huang,Haidong Chen,Xilin Gan,Yi Liu,Shubei Wan,Bo Zhu,Zhanjun Lu,Xianhong Ge,Qinyong Yang,Terezie Mandáková,Xinyi Guo,Chen Tan,Martin A Lysak","doi":"10.1093/plphys/kiag133","DOIUrl":"https://doi.org/10.1093/plphys/kiag133","url":null,"abstract":"Wallflower (Erysimum cheiri) belongs to the monogeneric Erysimeae tribe of the mustard family (Brassicaceae). It is widely cultivated as an ornamental garden plant and appreciated for its diverse flower colors. However, the absence of a high-quality genome has hampered research on wallflower genome evolution and the mechanisms underlying variations in flower color. Here, we assembled a nearly gap-free telomere-to-telomere genome of E. cheiri. The assembled genome enabled the reconstruction of genome evolution in the genus Erysimum (274 species), tracing the changes from the ancestral n = 8 genome (in E. cheiranthoides) to the derived genomes with seven (in E. nevadense) and six (in E. cheiri) chromosome pairs. While the reduction from n = 8 to n = 7 was mediated by a nested chromosome fusion accompanied by inversions, the further decrease to n = 6 in E. cheiri resulted from an end-to-end translocation involving the other two non-homologous chromosomes. Compared with other Brassicaceae species, E. cheiri showed a notable expansion of gene families related to secondary metabolite biosynthesis. Its flower color variation was primarily determined by the biosynthesis and accumulation of carotenoids and flavonoids. We mapped the metabolic pathways for carotenoids and flavonoids, identifying the hub genes regulating their biosynthesis. This research lays an important foundation for understanding the chromosomal and genome evolution of the Erysimeae tribe and paves the way for future investigations into genetic studies and breeding applications of E. cheiri.","PeriodicalId":20101,"journal":{"name":"Plant Physiology","volume":"60 1","pages":""},"PeriodicalIF":7.4,"publicationDate":"2026-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147446863","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Shoots of Ma bamboo (Dendrocalamus latiflorus) are widely valued for their high yield, extended harvest period, and nutritional richness. Despite their economic and ecological importance, the epigenetic mechanisms governing shoot development remain largely unexplored. Here, we integrated cytological, transcriptomic, proteomic, and multi-epigenomic analyses to characterize the developmental gradient from the basal mature region to the apical proliferative zone. Cytological observation revealed a transition from structurally reinforced cells at the basal internode to actively dividing cells at the apical internode. Genome-wide bisulfite sequencing showed a progressive increase in CG methylation and a decrease in CHG methylation within gene bodies, accompanied by promoter-enriched CHH methylation that was positively correlated with transcriptional activation. Chromatin profiling demonstrated elevated H3K36me3 active marks and enhanced chromatin accessibility at the apical internode. In contrast, N6-methyladenosine (m6A) levels declined from the basal internode to the apical internode, coinciding with the activation of growth-related genes. Using nanopore-based sequencing, we further found that Poly(A) tail lengths (PALs) were positively associated with m6A accumulation and gene body CG methylation but negatively correlated with H3K27me3 and H3K36me3 levels. Together, this study establishes an integrated epigenetic framework in which DNA methylation, histone modifications, m6A, and PAL dynamics collectively fine-tune transcription and translation during bamboo shoot elongation. Our study provides a multi-epigenomic model for D. latiflorus development and broadens our understanding of epigenetic coordination in a monocot, thereby offering valuable insights for future genetic improvement.
{"title":"Epigenomic reprogramming underlies internodal developmental heterogeneity in rapidly elongating bamboo shoots.","authors":"Zeyu Zhang,Lin Wu,Deming Yang,Tian Hua,Yingjie Yan,Jun Zhang,Huiyuan Wang,Xuqing Liu,Liangzhen Zhao,Hangxiao Zhang,Yaxin Zhang,Lianfeng Gu","doi":"10.1093/plphys/kiag131","DOIUrl":"https://doi.org/10.1093/plphys/kiag131","url":null,"abstract":"Shoots of Ma bamboo (Dendrocalamus latiflorus) are widely valued for their high yield, extended harvest period, and nutritional richness. Despite their economic and ecological importance, the epigenetic mechanisms governing shoot development remain largely unexplored. Here, we integrated cytological, transcriptomic, proteomic, and multi-epigenomic analyses to characterize the developmental gradient from the basal mature region to the apical proliferative zone. Cytological observation revealed a transition from structurally reinforced cells at the basal internode to actively dividing cells at the apical internode. Genome-wide bisulfite sequencing showed a progressive increase in CG methylation and a decrease in CHG methylation within gene bodies, accompanied by promoter-enriched CHH methylation that was positively correlated with transcriptional activation. Chromatin profiling demonstrated elevated H3K36me3 active marks and enhanced chromatin accessibility at the apical internode. In contrast, N6-methyladenosine (m6A) levels declined from the basal internode to the apical internode, coinciding with the activation of growth-related genes. Using nanopore-based sequencing, we further found that Poly(A) tail lengths (PALs) were positively associated with m6A accumulation and gene body CG methylation but negatively correlated with H3K27me3 and H3K36me3 levels. Together, this study establishes an integrated epigenetic framework in which DNA methylation, histone modifications, m6A, and PAL dynamics collectively fine-tune transcription and translation during bamboo shoot elongation. Our study provides a multi-epigenomic model for D. latiflorus development and broadens our understanding of epigenetic coordination in a monocot, thereby offering valuable insights for future genetic improvement.","PeriodicalId":20101,"journal":{"name":"Plant Physiology","volume":"19 1","pages":""},"PeriodicalIF":7.4,"publicationDate":"2026-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147394001","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Gibberellin (GA) biosynthesis and signaling play important roles in seed setting and grain weight; however, how long-distance GA transport contributes to these traits remains poorly understood. Here, we characterized the Nitrate transporter 1/Peptide transporter Family (NPF) protein OsNPF3.5, which mediates GA allocation in rice (Oryza sativa L. var. Nipponbare). OsNPF3.5 was preferentially expressed in the phloem of the leaf blade at the reproductive stage and was responsive to lower temperatures. Ectopic expression of OsNPF3.5 in Xenopus laevis oocytes showed relatively low uptake activity for GA3,4,7 and abscisic acid (ABA), but a significant efflux activity for GA44 across the plasma membrane. Compared to the wild type, pollen fertility, seed setting rate, 1000-grain weight, and grain yield were decreased in osnpf3.5. Moreover, functional disruption of OsNPF3.5 essentially decreased GA44 redistribution from the flag leaf blade and was accompanied by decreased levels of GA3 in anthers and GA1 in caryopses. These results suggest that OsNPF3.5 functions as a GA44 efflux transporter promoting GA44 loading into phloem, thus facilitating GA allocation from flag leaf blade to sink organs including anthers and caryopses, which consequently regulates seed setting, 1000-grain weight and grain yield. This represents a mechanism by which long-distance GA precursor transport gets involved in rice seed setting and grain weight formation under variable environmental conditions.
赤霉素（giberellin， GA）的生物合成和信号转导在结实率和粒重中起重要作用；然而，对于遗传基因长距离运输对这些性状的影响，人们仍然知之甚少。在这里，我们鉴定了硝酸盐转运蛋白1/肽转运蛋白家族（NPF） OsNPF3.5，该蛋白介导水稻（Oryza sativa L. var. Nipponbare） GA分配。OsNPF3.5在繁殖期优先表达于叶片韧皮部，对低温有响应。OsNPF3.5异位表达的非洲爪蟾卵母细胞对GA3、4、7和脱落酸（ABA）的摄取活性相对较低，但对GA44的跨质膜外排活性显著。与野生型相比，osnpf3.5的花粉育性、结实率、千粒重和籽粒产量均有所降低。此外，OsNPF3.5的功能破坏基本上减少了旗叶GA44的再分配，并伴随着花药中GA3和颖果中GA1水平的降低。综上所述，OsNPF3.5作为GA44外排转运体，促进GA44向韧皮部转运，促进GA44从旗叶向花药、颖果等汇质器官分配，从而调控结实率、千粒重和产量。这表明在不同的环境条件下，遗传前体转运参与水稻结实和粒重形成的机制。
{"title":"OsNPF3.5 mediates gibberellin allocation and grain yield in rice.","authors":"Ting-Ting Wen,Zhi-Jun Liu,Jing Yan,Yu-Ting Lu,Si-Ying Chen,Hua-Peng Qiu,Hui Li,Zi-Jun Fang,Chun-Peng Song,Jing-Fang Chu,Ji-Ming Gong","doi":"10.1093/plphys/kiag130","DOIUrl":"https://doi.org/10.1093/plphys/kiag130","url":null,"abstract":"Gibberellin (GA) biosynthesis and signaling play important roles in seed setting and grain weight; however, how long-distance GA transport contributes to these traits remains poorly understood. Here, we characterized the Nitrate transporter 1/Peptide transporter Family (NPF) protein OsNPF3.5, which mediates GA allocation in rice (Oryza sativa L. var. Nipponbare). OsNPF3.5 was preferentially expressed in the phloem of the leaf blade at the reproductive stage and was responsive to lower temperatures. Ectopic expression of OsNPF3.5 in Xenopus laevis oocytes showed relatively low uptake activity for GA3,4,7 and abscisic acid (ABA), but a significant efflux activity for GA44 across the plasma membrane. Compared to the wild type, pollen fertility, seed setting rate, 1000-grain weight, and grain yield were decreased in osnpf3.5. Moreover, functional disruption of OsNPF3.5 essentially decreased GA44 redistribution from the flag leaf blade and was accompanied by decreased levels of GA3 in anthers and GA1 in caryopses. These results suggest that OsNPF3.5 functions as a GA44 efflux transporter promoting GA44 loading into phloem, thus facilitating GA allocation from flag leaf blade to sink organs including anthers and caryopses, which consequently regulates seed setting, 1000-grain weight and grain yield. This represents a mechanism by which long-distance GA precursor transport gets involved in rice seed setting and grain weight formation under variable environmental conditions.","PeriodicalId":20101,"journal":{"name":"Plant Physiology","volume":"79 1","pages":""},"PeriodicalIF":7.4,"publicationDate":"2026-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147383621","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Cold stress limits the growth and distribution of warm-season grasses such as bermudagrass (Cynodon dactylon). While jasmonic acid (JA) accumulates under cold conditions, the regulatory mechanisms underlying cold adaptation in bermudagrass remain largely unknown. Here, we demonstrate that exogenous methyl jasmonate (MeJA) significantly enhances cold tolerance in bermudagrass. Proteomic analysis identified JA-Activated Cold-responsive Gene 1 (CdJACG1), which was found to accumulate under cold stress in bermudagrass. Overexpression of CdJACG1 enhanced cold tolerance, whereas knockdown of CdJACG1 expression increased cold susceptibility in bermudagrass. Protein-DNA interaction assays revealed that CdMYC2, a positive regulator of cold tolerance, directly binds to the promoter of CdJACG1, suggesting that it directly activates CdJACG1 expression. Both CdJACG1 and CdMYC2 bound to the promoters of allene oxide synthase 2 (CdAOS2) and 12-oxophytodienoate reductase 1 (CdOPR1), thereby amplifying JA accumulation. Heterologous expression of CdAOS2 or CdOPR1 in Arabidopsis thaliana enhanced cold tolerance. Beyond its role in JA signaling, CdJACG1 integrates with the C-repeat binding factor (CBF)-mediated cold signaling pathway by directly activating the expression of dehydration-responsive element-binding protein 1.3 (CdDREB1.3), a known positive regulator of plant cold tolerance. Collectively, our findings reveal a potential regulatory module involving CdJACG1 and CBF/DREB1. This module is likely directly regulated by CdMYC2 and synergistically integrates JA signaling with the CBF/DREB1-dependent pathway to enhance cold tolerance in bermudagrass. Our work thus provides crucial insights for molecular breeding of cold-tolerant warm-season grasses and crops.
{"title":"CdJACG1 integrates jasmonic acid signaling and CBF pathways to confer cold tolerance in bermudagrass (Cynodon dactylon).","authors":"Xuebing Huang,Shurui Song,Miaomiao Zhou,Guangjing Ma,Zhengrong Hu,Liang Chen","doi":"10.1093/plphys/kiag129","DOIUrl":"https://doi.org/10.1093/plphys/kiag129","url":null,"abstract":"Cold stress limits the growth and distribution of warm-season grasses such as bermudagrass (Cynodon dactylon). While jasmonic acid (JA) accumulates under cold conditions, the regulatory mechanisms underlying cold adaptation in bermudagrass remain largely unknown. Here, we demonstrate that exogenous methyl jasmonate (MeJA) significantly enhances cold tolerance in bermudagrass. Proteomic analysis identified JA-Activated Cold-responsive Gene 1 (CdJACG1), which was found to accumulate under cold stress in bermudagrass. Overexpression of CdJACG1 enhanced cold tolerance, whereas knockdown of CdJACG1 expression increased cold susceptibility in bermudagrass. Protein-DNA interaction assays revealed that CdMYC2, a positive regulator of cold tolerance, directly binds to the promoter of CdJACG1, suggesting that it directly activates CdJACG1 expression. Both CdJACG1 and CdMYC2 bound to the promoters of allene oxide synthase 2 (CdAOS2) and 12-oxophytodienoate reductase 1 (CdOPR1), thereby amplifying JA accumulation. Heterologous expression of CdAOS2 or CdOPR1 in Arabidopsis thaliana enhanced cold tolerance. Beyond its role in JA signaling, CdJACG1 integrates with the C-repeat binding factor (CBF)-mediated cold signaling pathway by directly activating the expression of dehydration-responsive element-binding protein 1.3 (CdDREB1.3), a known positive regulator of plant cold tolerance. Collectively, our findings reveal a potential regulatory module involving CdJACG1 and CBF/DREB1. This module is likely directly regulated by CdMYC2 and synergistically integrates JA signaling with the CBF/DREB1-dependent pathway to enhance cold tolerance in bermudagrass. Our work thus provides crucial insights for molecular breeding of cold-tolerant warm-season grasses and crops.","PeriodicalId":20101,"journal":{"name":"Plant Physiology","volume":"267 1","pages":""},"PeriodicalIF":7.4,"publicationDate":"2026-03-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147381196","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"New molecular pieces in the jigsaw of extracellular vesicle biogenesis.","authors":"Josephine H R Maidment,Marcella Teixeira","doi":"10.1093/plphys/kiag124","DOIUrl":"https://doi.org/10.1093/plphys/kiag124","url":null,"abstract":"","PeriodicalId":20101,"journal":{"name":"Plant Physiology","volume":"226 1","pages":""},"PeriodicalIF":7.4,"publicationDate":"2026-03-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147381197","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The plasma membrane (PM) proton (H+)-ATPase plays an important role in regulating plant growth, development, and acclimation to environmental stress. The inhibition of PM H+-ATPase promotes stomatal closure and reduces transpirational water loss under drought stress. Although calcium (Ca2+) signals modulate PM H+-ATPase activity, the underlying mechanism remains unknown. In this study, we found that Arabidopsis (Arabidopsis thaliana) CALCIUM-DEPENDENT KINASE 8 (CPK8) physically interacts with and phosphorylates PLASMA MEMBRANE PROTON ATPASE 1 (AHA1) at the conserved serine residue Ser-899 in the C-terminal region. CPK8-mediated phosphorylation of AHA1 significantly inhibits its H+-ATPase activity. CPK8 overexpression significantly ameliorated the excessive transpirational water loss while concurrently elevating leaf temperature in open stomata 2-2D (ost2-2D), a mutant with constitutively activated PM H+-ATPase. In addition, drought-induced Ca2+ signal activates CPK8, which further modulates PM H+-ATPase activity under drought stress. Our findings indicate that CPK8 phosphorylates PM H+-ATPase to fine-tune stomatal closure and optimize plant drought tolerance.
{"title":"The CPK8-AHA1 phosphorylation module dampens plasma membrane H+-ATPase activity to confer drought tolerance.","authors":"Xiao Liu,Dongmin Zhang,Yongqing Yang,Liang Ma","doi":"10.1093/plphys/kiag128","DOIUrl":"https://doi.org/10.1093/plphys/kiag128","url":null,"abstract":"The plasma membrane (PM) proton (H+)-ATPase plays an important role in regulating plant growth, development, and acclimation to environmental stress. The inhibition of PM H+-ATPase promotes stomatal closure and reduces transpirational water loss under drought stress. Although calcium (Ca2+) signals modulate PM H+-ATPase activity, the underlying mechanism remains unknown. In this study, we found that Arabidopsis (Arabidopsis thaliana) CALCIUM-DEPENDENT KINASE 8 (CPK8) physically interacts with and phosphorylates PLASMA MEMBRANE PROTON ATPASE 1 (AHA1) at the conserved serine residue Ser-899 in the C-terminal region. CPK8-mediated phosphorylation of AHA1 significantly inhibits its H+-ATPase activity. CPK8 overexpression significantly ameliorated the excessive transpirational water loss while concurrently elevating leaf temperature in open stomata 2-2D (ost2-2D), a mutant with constitutively activated PM H+-ATPase. In addition, drought-induced Ca2+ signal activates CPK8, which further modulates PM H+-ATPase activity under drought stress. Our findings indicate that CPK8 phosphorylates PM H+-ATPase to fine-tune stomatal closure and optimize plant drought tolerance.","PeriodicalId":20101,"journal":{"name":"Plant Physiology","volume":"45 1","pages":""},"PeriodicalIF":7.4,"publicationDate":"2026-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147368439","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Non-structural carbohydrates (NSCs), comprising soluble sugars and starch, serve as critical metabolic reserves buffering trees against temporal carbon supply-demand imbalances. Despite their functional importance, diel NSC dynamics in trees remain elusive, which limits mechanistic understanding of carbon allocation strategies and also restricts the consistency in sampling protocols. Here, we conducted a high-resolution analysis of diel NSC dynamics in leaves and branches of 15 tree species across four climatically distinct sites in western China using generalized additive mixed models and a simplified proportional-integral-derivative (PID) control framework. We found that starch and soluble sugars exhibited consistent diel patterns, peaking in the late afternoon and declining to minima before dawn. Starch peaked earlier and exhibited greater amplitudes than soluble sugars, thereby dominating fluctuations of total NSC concentration. Mid-morning (09:00-11:00) concentration of NSC fractions closely approximated diel means, offering a practical benchmark for standardized sampling. Variation in diel means and amplitudes were explained more by environmental contexts, particularly vapor pressure deficit (VPD), than by species identity, while trait associations revealed that wood density correlated negatively with diel means and diameter at breast height (DBH) with diel amplitudes. Diel NSC dynamics were actively regulated and coordinated across tissues, with environmental conditions modulating both their magnitude and central tendency. This study highlights the importance of incorporating temporal resolution, environmental context, and trait-based trade-offs into assessments of plant carbon status, providing insights to refine process-based models of carbon allocation and resilience under climate change.
{"title":"High-resolution diel dynamics of non-structural carbohydrates in trees reveal organ-level coordination and trait-environment coupling.","authors":"Weibin Li,Yingyi Pu,Fan Li,Yanjing Jiang","doi":"10.1093/plphys/kiag123","DOIUrl":"https://doi.org/10.1093/plphys/kiag123","url":null,"abstract":"Non-structural carbohydrates (NSCs), comprising soluble sugars and starch, serve as critical metabolic reserves buffering trees against temporal carbon supply-demand imbalances. Despite their functional importance, diel NSC dynamics in trees remain elusive, which limits mechanistic understanding of carbon allocation strategies and also restricts the consistency in sampling protocols. Here, we conducted a high-resolution analysis of diel NSC dynamics in leaves and branches of 15 tree species across four climatically distinct sites in western China using generalized additive mixed models and a simplified proportional-integral-derivative (PID) control framework. We found that starch and soluble sugars exhibited consistent diel patterns, peaking in the late afternoon and declining to minima before dawn. Starch peaked earlier and exhibited greater amplitudes than soluble sugars, thereby dominating fluctuations of total NSC concentration. Mid-morning (09:00-11:00) concentration of NSC fractions closely approximated diel means, offering a practical benchmark for standardized sampling. Variation in diel means and amplitudes were explained more by environmental contexts, particularly vapor pressure deficit (VPD), than by species identity, while trait associations revealed that wood density correlated negatively with diel means and diameter at breast height (DBH) with diel amplitudes. Diel NSC dynamics were actively regulated and coordinated across tissues, with environmental conditions modulating both their magnitude and central tendency. This study highlights the importance of incorporating temporal resolution, environmental context, and trait-based trade-offs into assessments of plant carbon status, providing insights to refine process-based models of carbon allocation and resilience under climate change.","PeriodicalId":20101,"journal":{"name":"Plant Physiology","volume":"20 1","pages":""},"PeriodicalIF":7.4,"publicationDate":"2026-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147359122","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Light plays a crucial role in regulating anthocyanin biosynthesis during flower coloration. However, the involvement of epigenetic modifications in light-induced flower coloration remains poorly understood. Here, we studied the rose cultivar Rosa hybrida cv. Spectra, which exhibits dramatic light-induced changes in petal coloration. Integrated analysis of the m6A methylome and the transcriptome revealed significant changes in both m6A modifications and the expression of the anthocyanidin synthase gene RhANS (C_AA159414.1) in response to direct light in the petals. Light induced m6A modifications in the coding sequence (CDS) region of RhANS and repressed m6A modification at the 3' untranslated region (3'UTR). m6A modification in the CDS region enhanced mRNA stability and the translation efficiency of RhANS, whereas modification in the 3'UTR exerted an opposing effect. The expression of the m6A demethylase genes RhALKBH10A (C_AA159415.1) and RhALKBH10B (C_AA159416.1) was repressed in petals under direct light conditions. Silencing RhALKBH10A/10B enhanced anthocyanin accumulation, increased m6A abundance at CDS sites, and concurrently reduced m6A abundance at the 3'UTR site of RhANS mRNA. Silencing RhANS abrogated the anthocyanin accumulation induced by RhALKBH10A/10B silencing. Our results reveal that light modulates m6A modifications to regulate mRNA stability and translation of RhANS, thereby driving petal coloration in rose.
{"title":"Light-induced m6A RNA modification regulates anthocyanin accumulation during rose petal coloration.","authors":"Yuerong Gao,Fengqing Wang,Ping Xia,Jie Zhang,Zhen Peng,Ziyan Liu,Chunxin Yu,Ye Wang,Runzhi Li,Shiwei Zhao,Liusheng Duan","doi":"10.1093/plphys/kiag082","DOIUrl":"https://doi.org/10.1093/plphys/kiag082","url":null,"abstract":"Light plays a crucial role in regulating anthocyanin biosynthesis during flower coloration. However, the involvement of epigenetic modifications in light-induced flower coloration remains poorly understood. Here, we studied the rose cultivar Rosa hybrida cv. Spectra, which exhibits dramatic light-induced changes in petal coloration. Integrated analysis of the m6A methylome and the transcriptome revealed significant changes in both m6A modifications and the expression of the anthocyanidin synthase gene RhANS (C_AA159414.1) in response to direct light in the petals. Light induced m6A modifications in the coding sequence (CDS) region of RhANS and repressed m6A modification at the 3' untranslated region (3'UTR). m6A modification in the CDS region enhanced mRNA stability and the translation efficiency of RhANS, whereas modification in the 3'UTR exerted an opposing effect. The expression of the m6A demethylase genes RhALKBH10A (C_AA159415.1) and RhALKBH10B (C_AA159416.1) was repressed in petals under direct light conditions. Silencing RhALKBH10A/10B enhanced anthocyanin accumulation, increased m6A abundance at CDS sites, and concurrently reduced m6A abundance at the 3'UTR site of RhANS mRNA. Silencing RhANS abrogated the anthocyanin accumulation induced by RhALKBH10A/10B silencing. Our results reveal that light modulates m6A modifications to regulate mRNA stability and translation of RhANS, thereby driving petal coloration in rose.","PeriodicalId":20101,"journal":{"name":"Plant Physiology","volume":"43 1","pages":""},"PeriodicalIF":7.4,"publicationDate":"2026-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147350698","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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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