The impact of low light intensities on plant disease outbreaks represents a major challenge for global crop security,as it frequently results in significant yield losses.However,the underlying mechanisms of the effect...The impact of low light intensities on plant disease outbreaks represents a major challenge for global crop security,as it frequently results in significant yield losses.However,the underlying mechanisms of the effect of low light on plant defense are still poorly understood.Here,using an RNA-seq approach,we found that the susceptibility of tomato to Pseudomonas syringae pv.tomato DC3000(Pst DC3000)under low light was associated with the oxidation-reduction process.Low light conditions exacerbated Pst DC3000-induced reactive oxygen species(ROS)accumulation and protein oxidation.Analysis of gene expression and enzyme activity of ascorbate peroxidase 2(APX2)and other antioxidant enzymes revealed that these defense responses were significantly induced by Pst DC3000 inoculation under normal light,whereas these genes and their associated enzyme activities were not responsive to pathogen inocula-tion under low light.Additionally,the reduced ascorbate to dehydroascorbate(AsA/DHA)ratio was lower under low light compared with normal light conditions upon Pst DC3000 inoculation.Furthermore,the apx2 mutants generated by a CRISPR-Cas9 gene-editing approach were more susceptible to Pst DC3000 under low light conditions.Notably,this increased susceptibility could be significantly reduced by exogenous AsA treatment.Collectively,our findings suggest that low-light-induced disease susceptibility is associated with increased cellular oxidative stress in tomato plants.This study sheds light on the intricate relationship between light conditions,oxidative stress,and plant defense responses,and may pave the way for improved crop protection strategies in low light environments.展开更多
Prolonged exposure to low temperatures during agricultural production often leads to fruit malformation in crops,significantly reducing market value.However,the underlying molecular mechanisms remain poorly understood...Prolonged exposure to low temperatures during agricultural production often leads to fruit malformation in crops,significantly reducing market value.However,the underlying molecular mechanisms remain poorly understood.In this study,we identify sugar transport protein 2(STP2)as a critical regulator of tomato fruit locule development under cold conditions.Low temperatures impair long-distance sucrose transport from leaves to shoot apices,resulting in reduced accumulation of glucose and arabinose.In response,STP2 expression is strongly upregulated in shoot apices,promoting glucose and arabinose transport.We found that the CLAVAT3-WUSCHEL(CLV3-WUS)regulatory module,which governs locule formation,relies on STP2-mediated sugar transport for CLV3 arabinosylation.Overexpression of STP2 promotes glucose and arabinose accumulation in shoot apices,enhances CLV3 arabinosylation and the WUS suppression,mitigating the multi-locular malformations induced by low temperatures.Conversely,disruption of STP2 function exacerbates locule number increases under low temperatures,which could not be rescued by exogenous sugar supplementation.Our findings reveal a key mechanism by which STP2-mediated sugar transport supports CLV3 arabinosylation to maintain fruit locule development under low temperatures,offering potential strategies to alleviate fruit malformations in winter crop cultivation.展开更多
基金Thisworkwas supported by the National Natural Science Foundation of China(32172650)the Key Research and Development Program of Zhejiang Province(2021C02040).
文摘The impact of low light intensities on plant disease outbreaks represents a major challenge for global crop security,as it frequently results in significant yield losses.However,the underlying mechanisms of the effect of low light on plant defense are still poorly understood.Here,using an RNA-seq approach,we found that the susceptibility of tomato to Pseudomonas syringae pv.tomato DC3000(Pst DC3000)under low light was associated with the oxidation-reduction process.Low light conditions exacerbated Pst DC3000-induced reactive oxygen species(ROS)accumulation and protein oxidation.Analysis of gene expression and enzyme activity of ascorbate peroxidase 2(APX2)and other antioxidant enzymes revealed that these defense responses were significantly induced by Pst DC3000 inoculation under normal light,whereas these genes and their associated enzyme activities were not responsive to pathogen inocula-tion under low light.Additionally,the reduced ascorbate to dehydroascorbate(AsA/DHA)ratio was lower under low light compared with normal light conditions upon Pst DC3000 inoculation.Furthermore,the apx2 mutants generated by a CRISPR-Cas9 gene-editing approach were more susceptible to Pst DC3000 under low light conditions.Notably,this increased susceptibility could be significantly reduced by exogenous AsA treatment.Collectively,our findings suggest that low-light-induced disease susceptibility is associated with increased cellular oxidative stress in tomato plants.This study sheds light on the intricate relationship between light conditions,oxidative stress,and plant defense responses,and may pave the way for improved crop protection strategies in low light environments.
基金supported by the Key Research and Development Program of China(2023YFD2000600)the National Natural Science Foundation of China(32430092)the Starry Night Science Fund of Zhejiang University Shanghai Institute for Advanced Study(SN-ZJU-SIAS-0011).
文摘Prolonged exposure to low temperatures during agricultural production often leads to fruit malformation in crops,significantly reducing market value.However,the underlying molecular mechanisms remain poorly understood.In this study,we identify sugar transport protein 2(STP2)as a critical regulator of tomato fruit locule development under cold conditions.Low temperatures impair long-distance sucrose transport from leaves to shoot apices,resulting in reduced accumulation of glucose and arabinose.In response,STP2 expression is strongly upregulated in shoot apices,promoting glucose and arabinose transport.We found that the CLAVAT3-WUSCHEL(CLV3-WUS)regulatory module,which governs locule formation,relies on STP2-mediated sugar transport for CLV3 arabinosylation.Overexpression of STP2 promotes glucose and arabinose accumulation in shoot apices,enhances CLV3 arabinosylation and the WUS suppression,mitigating the multi-locular malformations induced by low temperatures.Conversely,disruption of STP2 function exacerbates locule number increases under low temperatures,which could not be rescued by exogenous sugar supplementation.Our findings reveal a key mechanism by which STP2-mediated sugar transport supports CLV3 arabinosylation to maintain fruit locule development under low temperatures,offering potential strategies to alleviate fruit malformations in winter crop cultivation.
