核农学报2017，Vol.31Issue(5)：979-986,8.DOI:10.11869/j.issn.100-8551.2017.05.0979
2,4-表油菜素内酯对亚适温弱光下黄瓜幼苗光合特性和抗氧化系统的影响
Effects of 2, 4-epibrassinolide on Photosynthesis Characteristics and Antioxidant System of Cucumber Seedlings Under Suboptimal Temperature and Low Light
摘要
Abstract
To explore the regulation mechanism of 2,4-epibrassionolide (EBR) on the growth of cucumber (Cucumis sativa L.) seedlings under suboptimal temperature and low light intensity (18/12 ℃,PFD 80 μ mol · m-2 · s-1),cucumber Youbol-5 was used as experimental material and seedlings sprayed with distilled water as the control.The method of spraying the seedling leaves with EBR was employed and the effects of EBR on chlorophyll content,gas exchange parameters,chlorophyll fluorescence parameters,the activities of key enzymes involved in calvin cycle and antioxidant enzymes were measured in cucumber seedlings under suboptimal temperature and low light.The results showed that compared with the control,the photosynthetic rate (Pn) and the relative chlorophyll content (SPAD) of seedlings in suboptimal temperature and low light treatment significantly decreased by 53.61％ and 21.73％,respectively.The malondialdehyde content of cucumber seedlings increased by 78.90％ and thus eventually led to the reduction of dry matter accumulation.However,the stressed cucumber seedlings pretreated with 0.1 μ mol· L-1 EBR maintained a higher value of specific leaf weight,Pn,SPAD,maximal photochemical efficiency of PS Ⅱ (Fv/Fm),actual photochemical efficiency of PS Ⅱ (ΦPS Ⅱ) and photochemical quenching coefficient (qP),but a decreased nonphotochemical quenching coefficient (NPQ).Moreover,EBR treatment significantly increased the activities of ribulose 1,5-biphosphate carboxylase/oxygenase (Rubisco),sedoheptulose-1,7-bisphosphatase (SBPase),fructose-1,6-bisphosphate aldolase (FBA) and transketolase (TK),and also promoted the activities of superoxide dismutase (SOD),peroxidase(POD),catalase(CAT),decreased the membrane lipid peroxidation.The results suggested that EBR could improve photosynthesis by increasing chlorophyll content,photochemistry efficiency and the activities of enzymes involved in Calvin cycle,enhance the antioxidant enzyme activities to decrease membrane lipid peroxidation,and thereby,effectively promote the growth of cucumber seedlings under suboptimal temperature and low light.Therefore,the findings provided a theoretical basis to clarify the regulation mechanism of the alleviation role of EBR on growth of cucumber seedlings under suboptimal temperature and low light.关键词
2,4-表油菜素内酯/亚适温弱光/黄瓜/光合作用/抗氧化Key words
2, 4-epibrassinolide/suboptimal temperature and low light/cucumber/photosynthesis/antioxidant引用本文复制引用
徐晓昀,郁继华,颉建明,胡琳莉..2,4-表油菜素内酯对亚适温弱光下黄瓜幼苗光合特性和抗氧化系统的影响[J].核农学报,2017,31(5):979-986,8.基金项目
甘肃省自然科学基金项目(145RJYA244),公益性行业(农业)科研专项经费(201203001) （145RJYA244）
