摘要
【目的】探究外源茉莉酸甲酯(MeJA)调控夏黑葡萄(Vitis vinifera‘Summer Black’)抗坏血酸-谷胱甘肽(AsAGSH)循环对低温胁迫的响应机制。【方法】以1年生夏黑葡萄植株为材料,设置不同浓度MeJA处理组和低温胁迫处理组,测定生长指标、AsA-GSH循环相关指标,并进行相关性分析。【结果】常温下,MeJA处理对夏黑葡萄生长指标、叶绿素含量和光合指标、AsA-GSH循环指标无显著影响。低温胁迫下,与喷施清水的对照相比,100μmol·L^(-1) MeJA处理组的茎粗和叶片数量显著增加,叶绿素含量及净光合速率(P_(n))、气孔导度(G_(s))和胞间二氧化碳浓度(C_(i))显著上升,蒸腾速率(T_(r))显著下降,缓解了低温对光合的抑制作用;同时100μmol·L^(-1) MeJA处理组的谷胱甘肽(GSH)含量及脱氢抗坏血酸还原酶(DHAR)、单脱氢抗坏血酸还原酶(MDHAR)和谷胱甘肽还原酶(GR)活性显著高于对照,提高了循环运转效率。相关性分析表明,经外源MeJA处理后,各指标间存在显著相关性。AsA含量与DHAR活性、MDHAR活性、GR活性、GSH含量、P_(n)等指标均呈极显著正相关,说明外源MeJA有助于增强AsA-GSH循环关键酶活性,提升AsA含量,促进GSH合成,提高光合效率。DHAR活性、MDHAR活性和GR活性之间呈极显著正相关,表明它们在AsA-GSH循环中协同作用,共同维持循环高效运转,清除活性氧。GSH含量与P_(n)、G_(s)呈显著正相关,说明GSH含量增加有利于提升光合作用效率。叶绿素a含量、叶绿素b含量与P_(n)、G_(s)呈显著正相关,与T_(r)呈显著负相关,表明叶绿素含量增加能促进光合作用,减少水分散失。此外,株高、茎粗和叶片数量等生长指标与部分光合及抗氧化指标存在一定相关性,说明植株生长与光合作用、抗氧化防御紧密相关,MeJA处理可通过调节这些指标间的关系,促进植株生长发育,提高抗寒性。【结论】明确了MeJA对低温胁迫下夏黑葡萄AsA-GSH循环的调控效果,筛选出MeJA最佳处理浓度为100μmol·L^(-1),为葡萄抗寒栽培提供了理论依据和技术支持。
【Objective】The aim of this study was to explore the response mechanism of the exogenous Methyl jasmonate(MeJA)regulating the ascorbic acid-glutathione(AsA-GSH)cycle of Vitis vinifera Summer Black grape to low-temperature stress.【Methods】One-year-old Summer Black grape plants were used as materials,and different concentrations of MeJA treatment groups and low-temperature stress treatment groups were set up.(1)MeJA treatment:the selected 1-year-old Summer Black grape plants were randomly divided into 5 groups,with 10 plants in each group.0(CK),50,100,150,200μmol·L^(-1) MeJA solution were sprayed on the leaves,and the spraying amount was suitable for the uniform wetting of the leaf surface without water dripping.The spraying time was selected in the evening of a sunny day to reduce the evaporation and photolysis of the solution.After treatment,the grape plants were cultured in normal growth environment(temperature 25±2℃,relative humidity 60%-70%,light intensity 2000-3000 lx,light time 16 h·d^(-1))for 24 h,so that MeJA could be fully absorbed and utilized by the plants;(2)low temperature stress treatment:24 h after MeJA treatment,each group of grape plants were randomly divided into two subgroups,one subgroup were continously placed in normal growth environment as normal temperature control,and the other subgroup was transferred to low temperature stress environment(temperature 0℃,relative humidity 60%-70%,light intensity 2000-3000 lx,light time 16 h·d^(-1)).The low temperature stress treatment time was set to 0(sampling before treatment as initial control),1,3 and 5 days.At each treatment time point,three grape plants were randomly selected from the normal temperature control group and the low temperature stress treatment group,and their functional leaves(the third to fifth fully expanded leaves from the top of the plant)were collected for the determination of various indicators.The collected leaf samples were quickly frozen with liquid nitrogen and stored in a refrigerator at -80℃ for standby.The growth indexes and AsA GSH cycle related indexes were measured.【Results】(1)at room temperature,the growth indexes and photosynthetic characteristics of the Summer Black grape under different concentrations of MeJA treatment had no significant difference fromthose of the control group at each time point after treatment,indicating that under normal growth environment,exogenous MeJA treatment had no significant effect on the growth indexes and photosynthetic characteristics of the Summer Black grape;Under low temperature stress,the plant height,stem diameter and leaf number of the control group increased slowly with the extension of stress time.The growth indexes of the experimental groups treated with MeJA under low temperature stress were better than those of the control group.Among them,the plant height,stem diameter and leaf number of 100μmol·L^(-1) MeJA treatment group increased significantly.100μmol·L^(-1) MeJA treatment could increase the chlorophyll a content,chlorophyll b content and total chlorophyll content,increase the utilization rate of light energy,and alleviate the damage of low temperature stress to grapes.The net photosynthetic rate,stomatal conductance and intercellular carbon dioxide concentration of the experimental groups treated with MeJA under low temperature stress were higher than those of the control group,and the 100μmol·L^(-1) MeJA treatment had significant effect.MeJA could alleviate the inhibition of grape photosynthesis under low temperature stress.The chlorophyll a and chlorophyll b were positively correlated with net photosynthetic rate and stomatal conductance,and negatively correlated with carbon dioxide concentration and transpiration rate.(2)The exogenous MeJA treatment could significantly improve the content of AsA and GSH and the activities of DHAR,MDHAR and GR enzymes in the Summer Black grape under low temperature stress,and enhance the efficiency of AsAGSH cycle.Under low temperature stress,the content of AsA in the control group increased slightly at the initial stage,then gradually decreased,and the content of GSH increased at the initial stage,and then gradually decreased,while the content of AsA and GSH in the experimental groups treated with MeJA were higher than those in the control group under low temperature stress,and the content of AsA and GSH in the 100μmol·L^(-1) MeJA treatment group remained at a high level after 5 days of low temperature stress;At the same time,the activities of DHAR,MDHAR and GR in 100μmol·L^(-1) MeJA treatment group were significantly higher than those in the control group after 5 days of low temperature stress(P<0.05).The exogenous MeJA treatment could maintain high AsA and GSH contents,enhance the antioxidant capacity of plants,and improve the tolerance of grapes to low temperature stress.The AsA content and GSH content in AsA-GSH cycle were positively correlated with the DHAR enzyme activity,MDHAR enzyme activity and GR enzyme activity.【Conclusion】This study clarified the regulation effect of MeJA on AsA-GSH cycle of the Summer Black grape under low temperature stress,and screened out the optimal treatment concentration,which would provide theoretical basis and technical support for cold resistant cultivation of grape.
作者
张少伟
朱乾焰
赵晓改
周冰
李鹏
李桂荣
ZHANG Shaowei;ZHU Qianyan;ZHAO Xiaogai;ZHOU Bing;LI Peng;LI Guirong(The Open University of Henan,Zhengzhou 450046,Henan,China;Henan Provincial Engineering Research Center for Rural Environmental Ecological Restoration and Planning Design,Zhengzhou 450046,Henan,China;School of Horticulture and Landscape Architecture,Henan Institute of Science and Technology,Xinxiang 453003,Henan,China)
出处
《果树学报》
北大核心
2025年第8期1722-1731,共10页
Journal of Fruit Science
基金
河南省重点研发专项(241111113200)
国家级大学生创新创业训练计划项目(202410467028)
河南开放大学2023年度创新人才支持计划(攀登工程:PDGC-2023-007)。
