Pub Date : 2025-03-13DOI: 10.1016/j.envexpbot.2025.106125
Viktoria Dietrich , Jörg Niederberger , Markus Hauck
Under ongoing climate change, the mechanisms controlling the vigor and growth performance of tree regeneration are still less understood than for mature trees. Using stable isotope signatures (δ13C, δ15N), we studied intrinsic water use efficiency (WUEi, with δ13C as a proxy) and N relations and their interaction in differently drought-tolerant temperate tree species. We conducted a Germany-wide field study representing independent precipitation, temperature, and N deposition levels, comparing European beech (Fagus sylvatica), sessile oak (Quercus petraea), silver fir (Abies alba), and Douglas fir (Pseudotsuga menziesii) in the regeneration stage. At high N deposition WUEi was decreased in all tree species and in beech in particular, as δ13C signatures became more negative. This suggests that high N loads give rise to a differentiated discussion of the drought tolerance of tree species depending on the level of N deposition. In the conifers direct uptake of N from atmospheric deposition was important, as indicated by increasing foliar δ15N with increasing N concentration. In the broadleaved trees with better decomposable leaf litter, the main effect of N deposition was indicated through low δ15N signatures suggesting an intensification of uptake from N mineralization. Foliar δ15N signatures, and hence presumed changes in mineralization, were affected by soil chemistry, mean annual precipitation and temperature, but may also be influenced by deposition or other soil properties, which must be acknowledged when considering our results. To complement our results, comparable studies should be conducted for mature forest stands, including ecophysiological measurements of leaf gas exchange or tree water relations.
{"title":"Stable isotope inferred intrinsic water use efficiency and its relation to N sources in temperate tree regeneration with increasing levels of N deposition, precipitation, and temperature","authors":"Viktoria Dietrich , Jörg Niederberger , Markus Hauck","doi":"10.1016/j.envexpbot.2025.106125","DOIUrl":"10.1016/j.envexpbot.2025.106125","url":null,"abstract":"<div><div>Under ongoing climate change, the mechanisms controlling the vigor and growth performance of tree regeneration are still less understood than for mature trees. Using stable isotope signatures (δ<sup>13</sup>C, δ<sup>15</sup>N), we studied intrinsic water use efficiency (WUE<sub>i</sub>, with δ<sup>13</sup>C as a proxy) and N relations and their interaction in differently drought-tolerant temperate tree species. We conducted a Germany-wide field study representing independent precipitation, temperature, and N deposition levels, comparing European beech (<em>Fagus sylvatica</em>), sessile oak (<em>Quercus petraea</em>), silver fir (<em>Abies alba</em>), and Douglas fir (<em>Pseudotsuga menziesii</em>) in the regeneration stage. At high N deposition WUE<sub>i</sub> was decreased in all tree species and in beech in particular, as δ<sup>13</sup>C signatures became more negative. This suggests that high N loads give rise to a differentiated discussion of the drought tolerance of tree species depending on the level of N deposition. In the conifers direct uptake of N from atmospheric deposition was important, as indicated by increasing foliar δ<sup>15</sup>N with increasing N concentration. In the broadleaved trees with better decomposable leaf litter, the main effect of N deposition was indicated through low δ<sup>15</sup>N signatures suggesting an intensification of uptake from N mineralization. Foliar δ<sup>15</sup>N signatures, and hence presumed changes in mineralization, were affected by soil chemistry, mean annual precipitation and temperature, but may also be influenced by deposition or other soil properties, which must be acknowledged when considering our results. To complement our results, comparable studies should be conducted for mature forest stands, including ecophysiological measurements of leaf gas exchange or tree water relations.</div></div>","PeriodicalId":11758,"journal":{"name":"Environmental and Experimental Botany","volume":"232 ","pages":"Article 106125"},"PeriodicalIF":4.5,"publicationDate":"2025-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143636284","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-08DOI: 10.1016/j.envexpbot.2025.106124
Malin C. Broberg , Melissa Chang Espino , Felicity Hayes , Ignacio Gonzalez Fernandez , Håkan Pleijel
Tropospheric ozone (O3) is a regional air pollutant, formed by solar radiation from nitrogen oxides and volatile organic compounds. It is known to impair crop yields. The mechanisms of O3 damage to plants are linked to gas exchange and carbon metabolism. The carbon isotopic signature in plant tissues represented by δ13C offers a time-integrating approach to assess the performance of plant gas exchange. We combined wheat grain δ13C data from seven O3 experiments performed in four countries (Switzerland, Spain, Sweden, United Kingdom). For one experiment δ13C data for stems were available. There was a significant positive relationship between grain δ13C and O3 exposure (R2=0.37). Using a relative scale to account for variation in the δ13C level among experiments, a stronger linear relationship was obtained (R2=0.77). Furthermore, the relative yield loss from O3 was negatively linked to the relative effect on δ13C (R2=0.72). Stems were more depleted in 13C than grain but also showed a significant, less steep, positive δ13C relationship with O3 exposure. The most important conclusion from the positive relationship between δ13C and O3 exposure is that the O3 effect on stomatal conductance dominates over the impairment of CO2 fixation by Rubisco. However, also discrimination associated with redistribution of carbohydrates from non-reproductive plant parts to grains can contribute to the O3 effect on δ13C. Based on the unified pattern of δ13C response over a range of experiments performed in different sites, we conclude that the mechanisms of O3 damage in wheat with respect to gas exchange are highly consistent.
{"title":"Ozone exposure consistently increases δ13C in wheat grain","authors":"Malin C. Broberg , Melissa Chang Espino , Felicity Hayes , Ignacio Gonzalez Fernandez , Håkan Pleijel","doi":"10.1016/j.envexpbot.2025.106124","DOIUrl":"10.1016/j.envexpbot.2025.106124","url":null,"abstract":"<div><div>Tropospheric ozone (O<sub>3</sub>) is a regional air pollutant, formed by solar radiation from nitrogen oxides and volatile organic compounds. It is known to impair crop yields. The mechanisms of O<sub>3</sub> damage to plants are linked to gas exchange and carbon metabolism. The carbon isotopic signature in plant tissues represented by δ<sup>13</sup>C offers a time-integrating approach to assess the performance of plant gas exchange. We combined wheat grain δ<sup>13</sup>C data from seven O<sub>3</sub> experiments performed in four countries (Switzerland, Spain, Sweden, United Kingdom). For one experiment δ<sup>13</sup>C data for stems were available. There was a significant positive relationship between grain δ<sup>13</sup>C and O<sub>3</sub> exposure (R<sup>2</sup>=0.37). Using a relative scale to account for variation in the δ<sup>13</sup>C level among experiments, a stronger linear relationship was obtained (R<sup>2</sup>=0.77). Furthermore, the relative yield loss from O<sub>3</sub> was negatively linked to the relative effect on δ<sup>13</sup>C (R<sup>2</sup>=0.72). Stems were more depleted in <sup>13</sup>C than grain but also showed a significant, less steep, positive δ<sup>13</sup>C relationship with O<sub>3</sub> exposure. The most important conclusion from the positive relationship between δ<sup>13</sup>C and O<sub>3</sub> exposure is that the O<sub>3</sub> effect on stomatal conductance dominates over the impairment of CO<sub>2</sub> fixation by Rubisco. However, also discrimination associated with redistribution of carbohydrates from non-reproductive plant parts to grains can contribute to the O<sub>3</sub> effect on δ<sup>13</sup>C. Based on the unified pattern of δ<sup>13</sup>C response over a range of experiments performed in different sites, we conclude that the mechanisms of O<sub>3</sub> damage in wheat with respect to gas exchange are highly consistent.</div></div>","PeriodicalId":11758,"journal":{"name":"Environmental and Experimental Botany","volume":"232 ","pages":"Article 106124"},"PeriodicalIF":4.5,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143609837","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-06DOI: 10.1016/j.envexpbot.2025.106123
Juncai Deng , Wenyu Yang , Ans Van der Vaet , Jacob Pollier , Ruben Vanholme , Wout Boerjan , Jiang Liu , Bartel Vanholme
Shade is a well-known environmental stressor that affects plant growth and development. However, little is understood about how parental shade stress impacts subsequent seed viability across generations. In this study, we exposed Arabidopsis plants to different shade signals, including reduced light quantity (RQ), reduced red/far-red ratio (RR), and a combination of both during the reproductive stage. While both RQ and RR treatments affected plant growth, only RR increased seed viability. Compared to seed coats developed under normal light conditions, the seed coats formed under RR conditions had a higher content and an altered composition of insoluble cell wall phenolics. By studying mutants impaired in the deposition of these phenolic polymers, we identified a positive relationship between the seed coat's insoluble phenolic content and seed viability. Further analysis found that seed coats with increased content of insoluble phenolic were less permeable, likely contributing to the higher seed viability. Taken together, we demonstrated that shade stress, particularly RR light conditions, during parental growth increases Arabidopsis seed viability by reducing seed coat permeability through the modification of its phenolic content and compositions.
{"title":"Parental shade stress increases Arabidopsis seed viability by modifying the phenolic hydrophobic barrier in the seed coats","authors":"Juncai Deng , Wenyu Yang , Ans Van der Vaet , Jacob Pollier , Ruben Vanholme , Wout Boerjan , Jiang Liu , Bartel Vanholme","doi":"10.1016/j.envexpbot.2025.106123","DOIUrl":"10.1016/j.envexpbot.2025.106123","url":null,"abstract":"<div><div>Shade is a well-known environmental stressor that affects plant growth and development. However, little is understood about how parental shade stress impacts subsequent seed viability across generations. In this study, we exposed Arabidopsis plants to different shade signals, including reduced light quantity (RQ), reduced red/far-red ratio (RR), and a combination of both during the reproductive stage. While both RQ and RR treatments affected plant growth, only RR increased seed viability. Compared to seed coats developed under normal light conditions, the seed coats formed under RR conditions had a higher content and an altered composition of insoluble cell wall phenolics. By studying mutants impaired in the deposition of these phenolic polymers, we identified a positive relationship between the seed coat's insoluble phenolic content and seed viability. Further analysis found that seed coats with increased content of insoluble phenolic were less permeable, likely contributing to the higher seed viability. Taken together, we demonstrated that shade stress, particularly RR light conditions, during parental growth increases Arabidopsis seed viability by reducing seed coat permeability through the modification of its phenolic content and compositions.</div></div>","PeriodicalId":11758,"journal":{"name":"Environmental and Experimental Botany","volume":"232 ","pages":"Article 106123"},"PeriodicalIF":4.5,"publicationDate":"2025-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143580437","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-01Epub Date: 2022-06-16DOI: 10.23736/S2724-6507.22.03750-2
Fudan Zhang, Xu Hou
Forkhead box O (FOXO) proteins are transcription factors that are involved in many physiological processes, including diabetes mellitus, which is a complex, multifactorial metabolic disorder. FOXO proteins are emerging as pivotal regulators in the progression of diabetes mellitus, mainly by inhibiting insulin or insulin-like growth factor, but little is known about their roles in diabetes mellitus. Although no targeted therapy exists to slow the development of diabetes and diabetes-related complications, several recent advances have clarified the molecular mechanisms underlying the disease. This review summarizes findings about FOXO proteins and diabetes mellitus, and sheds new light on the roles of FOXO proteins in diabetes mellitus.
{"title":"The role of Forkhead box O in diabetes mellitus.","authors":"Fudan Zhang, Xu Hou","doi":"10.23736/S2724-6507.22.03750-2","DOIUrl":"10.23736/S2724-6507.22.03750-2","url":null,"abstract":"<p><p>Forkhead box O (FOXO) proteins are transcription factors that are involved in many physiological processes, including diabetes mellitus, which is a complex, multifactorial metabolic disorder. FOXO proteins are emerging as pivotal regulators in the progression of diabetes mellitus, mainly by inhibiting insulin or insulin-like growth factor, but little is known about their roles in diabetes mellitus. Although no targeted therapy exists to slow the development of diabetes and diabetes-related complications, several recent advances have clarified the molecular mechanisms underlying the disease. This review summarizes findings about FOXO proteins and diabetes mellitus, and sheds new light on the roles of FOXO proteins in diabetes mellitus.</p>","PeriodicalId":11758,"journal":{"name":"Environmental and Experimental Botany","volume":"48 1","pages":"105-112"},"PeriodicalIF":4.5,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78181417","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}
In rice (Oryza sativa), the upper position (top 1/3) of the panicle exhibits superior spikelet development compared with the basal position (basal 1/3), particularly under high temperature (HT). In this study, the rice cultivar Yongyou 538 (susceptible to spikelet degeneration) was subjected to HT to investigate the physiological mechanism underlying positional differences in spikelet degeneration in the panicle by conducting comparative transcriptome and physiological analyses. The basal position of panicles showed more degenerated spikelets compared with the upper under normal temperature and HT, with HT aggravating this degeneration. Spikelet development depends on carbohydrate availability. In total, 1144 genes associated with spikelet development were differentially expressed in the upper and basal, primarily involving starch and sucrose metabolism. Under normal temperature and HT, the expression levels of sucrose transporter genes were lower in the basal, indicating sucrose transport was blocked there. Sucrose, a type of soluble sugar, accumulated more appreciably in the basal position under HT, whereas total soluble sugar content exhibited the opposite trend. It is associated with sucrose hydrolysis enzyme activities were markedly reduced, indicating impaired sucrose utilization. Simultaneously, decreased activities of TCA cycle-related enzymes led to NAD+ accumulation and increase in reactive oxygen species production. Lower antioxidant enzyme activities in the basal resulted in substantial reactive oxygen species accumulation. In conclusion, significant positional differences in spikelet formation along the panicle are characterized by extensive degeneration of spikelets in the basal position, owing to impaired sucrose utilization in this region, leading to peroxide accumulation and inhibition of spikelet development.
{"title":"Positional differences of rice spikelet formation under high temperature are associated with sucrose utilization discrepancy","authors":"Jingqing Wang, Hui Li, Tianming Lan, Chenghan Tang, Peng Zhang, Yulin Chen, Huizhe Chen, Jing Xiang, Yikai Zhang, Zhigang Wang, Yuping Zhang, Yaliang Wang","doi":"10.1016/j.envexpbot.2025.106114","DOIUrl":"10.1016/j.envexpbot.2025.106114","url":null,"abstract":"<div><div>In rice (<em>Oryza sativa</em>), the upper position (top 1/3) of the panicle exhibits superior spikelet development compared with the basal position (basal 1/3), particularly under high temperature (HT). In this study, the rice cultivar Yongyou 538 (susceptible to spikelet degeneration) was subjected to HT to investigate the physiological mechanism underlying positional differences in spikelet degeneration in the panicle by conducting comparative transcriptome and physiological analyses. The basal position of panicles showed more degenerated spikelets compared with the upper under normal temperature and HT, with HT aggravating this degeneration. Spikelet development depends on carbohydrate availability. In total, 1144 genes associated with spikelet development were differentially expressed in the upper and basal, primarily involving starch and sucrose metabolism. Under normal temperature and HT, the expression levels of sucrose transporter genes were lower in the basal, indicating sucrose transport was blocked there. Sucrose, a type of soluble sugar, accumulated more appreciably in the basal position under HT, whereas total soluble sugar content exhibited the opposite trend. It is associated with sucrose hydrolysis enzyme activities were markedly reduced, indicating impaired sucrose utilization. Simultaneously, decreased activities of TCA cycle-related enzymes led to NAD<sup>+</sup> accumulation and increase in reactive oxygen species production. Lower antioxidant enzyme activities in the basal resulted in substantial reactive oxygen species accumulation. In conclusion, significant positional differences in spikelet formation along the panicle are characterized by extensive degeneration of spikelets in the basal position, owing to impaired sucrose utilization in this region, leading to peroxide accumulation and inhibition of spikelet development.</div></div>","PeriodicalId":11758,"journal":{"name":"Environmental and Experimental Botany","volume":"232 ","pages":"Article 106114"},"PeriodicalIF":4.5,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143535048","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-26DOI: 10.1016/j.envexpbot.2025.106122
Xiaoqun Cao , Yan Xiang , Yuanfeng Hu , Ming Zhang , Xufeng Xiao , Fengrui Yin , Liangdeng Wang , Meilan Sui , Yuekeng Yao
Cadmium (Cd) is one of the highly toxic heavy metals that restricts plant growth, affects crop yields, and triggers food crises. Dimethyl sulfoxide (DMSO) is frequently used solvent in biological studies, and its potential application in resistance to Cd toxicity in plants and animals has not been reported. Here, low concentrations of DMSO alone were demonstrated to increase the biomass of pak choi seedlings; more importantly, under Cd stress conditions, DMSO was shown to reduce Cd accumulation, and thereby alleviate Cd-induced damages. Specifically, DMSO could enhance plant defense mechanisms against Cd stress by strengthening the activities of endogenous reactive oxygen species (ROS) -scavenging enzymatic or non-enzymatic antioxidants, regulating the expression of key stress-responsive genes, as well as activating autophagy and apoptosis protection in root cells, thereby scavenging excessive ROS, restoring integration of cell membranes, and conferring tolerance to Cd-induced phytotoxicity. Our results showed that DMSO could play a vital role in mitigating Cd-induced oxidative damage by activating the protective mechanisms generated by the synergistic effects of both autophagy and antioxidants. These findings will help to formulate strategies to mitigate Cd contamination and to ensure the safety of cabbage production, an important vegetable source.
{"title":"Dimethyl sulfoxide synergistically mitigates cadmium-induced oxidative damage in pak choi by activating antioxidant and autophagy mechanisms","authors":"Xiaoqun Cao , Yan Xiang , Yuanfeng Hu , Ming Zhang , Xufeng Xiao , Fengrui Yin , Liangdeng Wang , Meilan Sui , Yuekeng Yao","doi":"10.1016/j.envexpbot.2025.106122","DOIUrl":"10.1016/j.envexpbot.2025.106122","url":null,"abstract":"<div><div>Cadmium (Cd) is one of the highly toxic heavy metals that restricts plant growth, affects crop yields, and triggers food crises. Dimethyl sulfoxide (DMSO) is frequently used solvent in biological studies, and its potential application in resistance to Cd toxicity in plants and animals has not been reported. Here, low concentrations of DMSO alone were demonstrated to increase the biomass of pak choi seedlings; more importantly, under Cd stress conditions, DMSO was shown to reduce Cd accumulation, and thereby alleviate Cd-induced damages. Specifically, DMSO could enhance plant defense mechanisms against Cd stress by strengthening the activities of endogenous reactive oxygen species (ROS) -scavenging enzymatic or non-enzymatic antioxidants, regulating the expression of key stress-responsive genes, as well as activating autophagy and apoptosis protection in root cells, thereby scavenging excessive ROS, restoring integration of cell membranes, and conferring tolerance to Cd-induced phytotoxicity. Our results showed that DMSO could play a vital role in mitigating Cd-induced oxidative damage by activating the protective mechanisms generated by the synergistic effects of both autophagy and antioxidants. These findings will help to formulate strategies to mitigate Cd contamination and to ensure the safety of cabbage production, an important vegetable source.</div></div>","PeriodicalId":11758,"journal":{"name":"Environmental and Experimental Botany","volume":"232 ","pages":"Article 106122"},"PeriodicalIF":4.5,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143593457","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-26DOI: 10.1016/j.envexpbot.2025.106121
Ties Ausma , Chiel-Jan Riezebos , Parisa Rahimzadeh Karvansara , Casper J. van der Kooi , Luit J. De Kok
The increased cultivation of highly productive C4 crop plants may contribute to a second green revolution in agriculture. However, the regulation of mineral nutrition is rather poorly understood in C4 plants. To understand the impact of C4 photosynthesis on the regulation of sulfate uptake by the root and sulfate assimilation into cysteine at the whole plant level, seedlings of the monocot C4 plant maize (Zea mays) were exposed to a non-toxic level of 1.0 µl l−1 atmospheric H2S at sulfate-sufficient and sulfate-deprived conditions. Sulfate deprivation not only affected growth and the levels of sulfur- and nitrogen-containing compounds, but it also enhanced the expression and activity of the sulfate transporters in the root and the expression and activity of APS reductase (APR) in the root and shoot. H2S exposure alleviated the establishment of sulfur deprivation symptoms and seedlings switched, at least partly, from sulfate to H2S as sulfur source. Moreover, H2S exposure resulted in a downregulation of the expression and activity of APR in both shoot and root, though it hardly affected that of the sulfate transporters in the root. These results indicate that maize seedlings respond similarly to sulfate deprivation and atmospheric H2S exposure as C3 monocots, implying that C4 photosynthesis in maize is not associated with a distinct whole plant regulation of sulfate uptake and assimilation into cysteine.
{"title":"Regulation of sulfur metabolism in seedlings of the C4 plant maize upon sulfate deprivation and atmospheric H2S exposure","authors":"Ties Ausma , Chiel-Jan Riezebos , Parisa Rahimzadeh Karvansara , Casper J. van der Kooi , Luit J. De Kok","doi":"10.1016/j.envexpbot.2025.106121","DOIUrl":"10.1016/j.envexpbot.2025.106121","url":null,"abstract":"<div><div>The increased cultivation of highly productive C<sub>4</sub> crop plants may contribute to a second green revolution in agriculture. However, the regulation of mineral nutrition is rather poorly understood in C<sub>4</sub> plants. To understand the impact of C<sub>4</sub> photosynthesis on the regulation of sulfate uptake by the root and sulfate assimilation into cysteine at the whole plant level, seedlings of the monocot C<sub>4</sub> plant maize (<em>Zea mays</em>) were exposed to a non-toxic level of 1.0 µl l<sup>−1</sup> atmospheric H<sub>2</sub>S at sulfate-sufficient and sulfate-deprived conditions. Sulfate deprivation not only affected growth and the levels of sulfur- and nitrogen-containing compounds, but it also enhanced the expression and activity of the sulfate transporters in the root and the expression and activity of APS reductase (APR) in the root and shoot. H<sub>2</sub>S exposure alleviated the establishment of sulfur deprivation symptoms and seedlings switched, at least partly, from sulfate to H<sub>2</sub>S as sulfur source. Moreover, H<sub>2</sub>S exposure resulted in a downregulation of the expression and activity of APR in both shoot and root, though it hardly affected that of the sulfate transporters in the root. These results indicate that maize seedlings respond similarly to sulfate deprivation and atmospheric H<sub>2</sub>S exposure as C<sub>3</sub> monocots, implying that C<sub>4</sub> photosynthesis in maize is not associated with a distinct whole plant regulation of sulfate uptake and assimilation into cysteine.</div></div>","PeriodicalId":11758,"journal":{"name":"Environmental and Experimental Botany","volume":"232 ","pages":"Article 106121"},"PeriodicalIF":4.5,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143549777","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-25DOI: 10.1016/j.envexpbot.2025.106120
Xinrui Wang , Xu Wang , Zhihui Sun, Chenhao Zhou, Zipei Fan, Guochao Yan, Yong He, Zhujun Zhu, Yunmin Xu
As sessile organisms, plants can modify their growth to adapt to the changed environment. Here, our results showed that shoot growth was more severely inhibited than root growth, resulting root:shoot ratio was increased in cucumber under osmotic stress. CsaMIR396E was highly expressed under well-watered condition, however, it was dramatically down-regulated to release its Growth-regulating factor (GRF) targets under osmotic stress in roots, but not in shoots. Exogenous abscisic acid (ABA) treatment suggested that down-regulation of CsaMIR396E in roots was depended on ABA signal. CmoMIR396E, the homolog of CsaMIR396E in pumpkin, exhibited a similar osmotic stress response pattern in pumpkin roots, and bioinformatic analysis showed that two motifs were conservatively presented within the promoter of MIR396E in cucurbits. Motif 1 harbored an ABA-response element (ABRE), while motif 2 harbored a (CT)n/(GA)n dinucleotide repeat element and functioned as an enhancer. Additionally, the role of CsaMIR396E in regulating root:shoot ratio under osmotic stress was confirmed by transgenic overexpression in Arabidopsis. In summary, our results suggested that CsaMIR396E acts as an osmotic stress response gene in roots, and it regulates root:shoot ratio by miR396-GRFs pathway under osmotic stress in cucumber.
{"title":"The role of CsaMIR396E-CsaGRFs in regulating root:shoot ratio under osmotic stress in cucumber","authors":"Xinrui Wang , Xu Wang , Zhihui Sun, Chenhao Zhou, Zipei Fan, Guochao Yan, Yong He, Zhujun Zhu, Yunmin Xu","doi":"10.1016/j.envexpbot.2025.106120","DOIUrl":"10.1016/j.envexpbot.2025.106120","url":null,"abstract":"<div><div>As sessile organisms, plants can modify their growth to adapt to the changed environment. Here, our results showed that shoot growth was more severely inhibited than root growth, resulting root:shoot ratio was increased in cucumber under osmotic stress. <em>CsaMIR396E</em> was highly expressed under well-watered condition, however, it was dramatically down-regulated to release its <em>Growth-regulating factor</em> (<em>GRF</em>) targets under osmotic stress in roots, but not in shoots. Exogenous abscisic acid (ABA) treatment suggested that down-regulation of <em>CsaMIR396E</em> in roots was depended on ABA signal. <em>CmoMIR396E</em>, the homolog of <em>CsaMIR396E</em> in pumpkin, exhibited a similar osmotic stress response pattern in pumpkin roots, and bioinformatic analysis showed that two motifs were conservatively presented within the promoter of <em>MIR396E</em> in cucurbits. Motif 1 harbored an ABA-response element (ABRE), while motif 2 harbored a (CT)<sub>n</sub>/(GA)<sub>n</sub> dinucleotide repeat element and functioned as an enhancer. Additionally, the role of <em>CsaMIR396E</em> in regulating root:shoot ratio under osmotic stress was confirmed by transgenic overexpression in Arabidopsis. In summary, our results suggested that <em>CsaMIR396E</em> acts as an osmotic stress response gene in roots, and it regulates root:shoot ratio by miR396-GRFs pathway under osmotic stress in cucumber.</div></div>","PeriodicalId":11758,"journal":{"name":"Environmental and Experimental Botany","volume":"232 ","pages":"Article 106120"},"PeriodicalIF":4.5,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143528885","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-24DOI: 10.1016/j.envexpbot.2025.106119
Alison R. Gill , Aaron L. Phillips , Stephen D. Tyerman , Tracy Lawson , Timothy R. Cavagnaro , Rachel A. Burton , Beth R. Loveys
As rainfall becomes increasingly erratic due to climate change, reliable water availability for crops will decrease, leading to reductions in crop productivity. Crops that can moderate water loss during periods of water deficit but rapidly upregulate physiological and photosynthetic processes when water is available will be valuable. In a controlled environment study, we used gas exchange and chlorophyll fluorescence methods to investigate how industrial hemp (Cannabis sativa L.) responds to differing watering frequencies (well-watered every two, four, or six days). Here, we report that hemp has a strong conserved relationship between stomatal conductance (gs) and assimilation (An), limiting water loss at the expense of biomass production. Generally, hemp exhibits low gs relative to high An, meaning that while a decrease in gs limits An, it shows favourable high intrinsic water use efficiency (Wi). Hemp stomata respond quickly to water re-supply, recovering rapidly from periods of water deficit via stomatal behavioural mechanisms and rapidly upregulating An. These stomatal behaviour traits mean hemp may be a suitable choice for water-efficient cropping in climates with sporadic water availability. Rapid stomatal responses in hemp could also be used to understand the interactions between An and Wi, and to help meet plant productivity targets without significant water losses.
{"title":"Water conservation and assimilation is driven by stomatal behaviour in industrial hemp (Cannabis sativa L.)","authors":"Alison R. Gill , Aaron L. Phillips , Stephen D. Tyerman , Tracy Lawson , Timothy R. Cavagnaro , Rachel A. Burton , Beth R. Loveys","doi":"10.1016/j.envexpbot.2025.106119","DOIUrl":"10.1016/j.envexpbot.2025.106119","url":null,"abstract":"<div><div>As rainfall becomes increasingly erratic due to climate change, reliable water availability for crops will decrease, leading to reductions in crop productivity. Crops that can moderate water loss during periods of water deficit but rapidly upregulate physiological and photosynthetic processes when water is available will be valuable. In a controlled environment study, we used gas exchange and chlorophyll fluorescence methods to investigate how industrial hemp (<em>Cannabis sativa</em> L.) responds to differing watering frequencies (well-watered every two, four, or six days). Here, we report that hemp has a strong conserved relationship between stomatal conductance (<em>g</em><sub>s</sub>) and assimilation (<em>A</em><sub>n</sub>), limiting water loss at the expense of biomass production. Generally, hemp exhibits low <em>g</em><sub>s</sub> relative to high <em>A</em><sub>n</sub>, meaning that while a decrease in <em>g</em><sub>s</sub> limits <em>A</em><sub>n</sub>, it shows favourable high intrinsic water use efficiency (<em>W</em><sub>i</sub>). Hemp stomata respond quickly to water re-supply, recovering rapidly from periods of water deficit via stomatal behavioural mechanisms and rapidly upregulating <em>A</em><sub>n</sub>. These stomatal behaviour traits mean hemp may be a suitable choice for water-efficient cropping in climates with sporadic water availability. Rapid stomatal responses in hemp could also be used to understand the interactions between <em>A</em><sub>n</sub> and <em>W</em><sub>i</sub>, and to help meet plant productivity targets without significant water losses.</div></div>","PeriodicalId":11758,"journal":{"name":"Environmental and Experimental Botany","volume":"232 ","pages":"Article 106119"},"PeriodicalIF":4.5,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143549855","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-22DOI: 10.1016/j.envexpbot.2025.106108
Kai Jiang , Xiaochen Hu , Qi Sun , German Spangenberg , Wei Tang , Wangdan Xiong , Yuzhu Wang , Xuanyang Wu , Zeng-yu Wang , Xueli Wu
Wetland salinization represents a significant global environmental challenge, threatening the viability and stability of both plant communities and ecosystems. There are few studies focused on species selection for the restoration of saline wetlands, specifically studies that integrate plant functional traits and molecular mechanisms. Juncus articulatus and Paspalum vaginatum, common perennial herbaceous species in freshwater or saline wetlands, are considered potential candidates for the restoration of saline wetlands. This study assessed phenotypic and physiological disparities in salt and cold tolerance and further employed an integrated transcriptomic and metabolomic approach to comprehensively elucidate the underlying mechanisms of cold tolerance. Under salinity treatments (400 mM NaCl for 5 days followed by 700 mM NaCl for 7 days with uniform irrigation), the survival rate of P. vaginatum reached 87.76 %. P. vaginatum exhibited significantly greater plant height and salt tolerance compared to J. articulatus. It also demonstrated higher proline content and elevated activities of SOD, POD, APX, ASA, and GSH. Additionally, Pn, Fv/Fm, and enzyme activities related to sucrose metabolism were significantly higher. Notably, under 700 mM NaCl salt conditions, P. vaginatum maintained significantly lower Na⁺ concentrations and higher K⁺/Na⁺ ratios in its leaves, as well as higher K⁺ concentrations and K⁺/Na⁺ ratios in its roots. J. articulatus possessed an extensive root system and exhibited significantly higher cold tolerance. After exposure to natural cold conditions during winter, with a minimum ground temperature of-6.5°C for 5 days, the plants exhibited markedly higher proline content and significantly higher activities of SOD, CAT, APX, and GSH. Although Pn exhibited a declining trend, it remained significantly higher than P. vaginatum. Cold stress induced significant transcription-associated metabolomic alterations in J. articulatus, enhancing cold tolerance through upregulated metabolic pathways including glutathione, starch and sucrose, and flavonoid biosynthesis. Under cold stress, it augmented its antioxidant defense by escalating glutathione synthesis and its precursors, L-Glutamate and NADP+. Meanwhile, it upregulated sucrose and trehalose levels and significantly increased activities of SS, SPS, and FBPase, which enhanced cold tolerance through the accumulation of soluble sugars. These findings provide valuable insights into the adaptive mechanisms of J. articulatus and P. vaginatum, offering crucial guidance for selecting resilient species in the restoration of saline and cold-affected wetlands.
{"title":"Integrating phenotypic and molecular approaches to unravel salinity and cold tolerance in wetland plants for ecosystem restoration","authors":"Kai Jiang , Xiaochen Hu , Qi Sun , German Spangenberg , Wei Tang , Wangdan Xiong , Yuzhu Wang , Xuanyang Wu , Zeng-yu Wang , Xueli Wu","doi":"10.1016/j.envexpbot.2025.106108","DOIUrl":"10.1016/j.envexpbot.2025.106108","url":null,"abstract":"<div><div>Wetland salinization represents a significant global environmental challenge, threatening the viability and stability of both plant communities and ecosystems. There are few studies focused on species selection for the restoration of saline wetlands, specifically studies that integrate plant functional traits and molecular mechanisms. <em>Juncus articulatus</em> and <em>Paspalum vaginatum</em>, common perennial herbaceous species in freshwater or saline wetlands, are considered potential candidates for the restoration of saline wetlands. This study assessed phenotypic and physiological disparities in salt and cold tolerance and further employed an integrated transcriptomic and metabolomic approach to comprehensively elucidate the underlying mechanisms of cold tolerance. Under salinity treatments (400 mM NaCl for 5 days followed by 700 mM NaCl for 7 days with uniform irrigation), the survival rate of <em>P. vaginatum</em> reached 87.76 %. <em>P. vaginatum</em> exhibited significantly greater plant height and salt tolerance compared to <em>J. articulatus</em>. It also demonstrated higher proline content and elevated activities of SOD, POD, APX, ASA, and GSH. Additionally, Pn, Fv/Fm, and enzyme activities related to sucrose metabolism were significantly higher. Notably, under 700 mM NaCl salt conditions, <em>P. vaginatum</em> maintained significantly lower Na⁺ concentrations and higher K⁺/Na⁺ ratios in its leaves, as well as higher K⁺ concentrations and K⁺/Na⁺ ratios in its roots. <em>J. articulatus</em> possessed an extensive root system and exhibited significantly higher cold tolerance. After exposure to natural cold conditions during winter, with a minimum ground temperature of-6.5°C for 5 days, the plants exhibited markedly higher proline content and significantly higher activities of SOD, CAT, APX, and GSH. Although Pn exhibited a declining trend, it remained significantly higher than <em>P. vaginatum</em>. Cold stress induced significant transcription-associated metabolomic alterations in <em>J. articulatus</em>, enhancing cold tolerance through upregulated metabolic pathways including glutathione, starch and sucrose, and flavonoid biosynthesis. Under cold stress, it augmented its antioxidant defense by escalating glutathione synthesis and its precursors, L-Glutamate and NADP<sup>+</sup>. Meanwhile, it upregulated sucrose and trehalose levels and significantly increased activities of SS, SPS, and FBPase, which enhanced cold tolerance through the accumulation of soluble sugars. These findings provide valuable insights into the adaptive mechanisms of <em>J. articulatus</em> and <em>P. vaginatum</em>, offering crucial guidance for selecting resilient species in the restoration of saline and cold-affected wetlands.</div></div>","PeriodicalId":11758,"journal":{"name":"Environmental and Experimental Botany","volume":"232 ","pages":"Article 106108"},"PeriodicalIF":4.5,"publicationDate":"2025-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143479062","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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