摘要
为研究质体末端氧化酶(PTOX)在大豆干旱胁迫中的作用,采用盆栽土培法考察干旱对大豆幼苗叶片中PTOX及环式光合电子传递(CET)的关键传递体([NAD(P)H]脱氢酶复合体NDH的H亚基NDH-H,质子梯度调节蛋白PGR5)基因表达的影响。结果表明,在干旱胁迫下PTOX表达水平明显升高,PGR5表达水平也有所升高,而NDH-H表达水平基本不变。同时,叶片蒸腾速率、气孔导度、胞间CO2浓度、净光合速率、叶绿素含量均明显降低,而类胡萝卜素的含量有所增加,表明干旱对大豆的光合作用产生了明显的影响。可推测,大豆叶片可能通过PTOX和PGR5转录水平的升高来响应干旱胁迫,通过依赖PGR5的CET及质体醌末端氧化能力的提高,避免光合链的过度还原;并且通过类胡萝卜素含量的升高,增强抗氧化的能力,对大豆起到一定的保护作用。
To understand the effect of plastid terminal oxidase（ PTOX） in soybean under drought,PTOX gene was studied. 2 essential components of CET（ cyclic electron transport）,NDH- H（ H- subunit of reduced nicotinamide adenine di（ tri）- nucleotide phosphate [NAD（ P） H] dehydrogenase complex） and PGR5（ the proton gradient regulation） were observed in leaves of pot- cultured soybean seedlings. Results showed that PTOX expression was up- regulated obviously under drought,and PGR5 was also up- regulated,while NDH- H remained unchanged. Simultaneously,transpiration rate,stomatal conduction,intercellular CO2 concentration,net photosynthetic rate and chlorophyll content of leaves decreased obviously,while carotenoid content increased,indicating a significant influence of drought on photosynthesis of soybean. Results suggested the up- regulation of PTOX and PGR5 expression were soybean responses to drought. Enhanced PGR5- dependent CET and terminal oxidation of plastoquinol could protect photosynthetic electron transport chain from over- reduction. In addition,increased carotenoid content might improve antioxidant capacity,which was beneficial for soybean under drought.
出处
《中国油料作物学报》
CAS
CSCD
北大核心
2015年第5期649-653,共5页
Chinese Journal of Oil Crop Sciences
基金
国家自然科学基金(31371555
31401308)
大学生创新训练计划项目
关键词
大豆
干旱
质体末端氧化酶
Soybean
Drought
Plastid terminal oxidase（PTOX）
