外源甜菜碱对干旱胁迫下小麦幼苗叶绿体抗氧化酶及psbA基因表达的调节  

Effects of Betaine on Chloroplast Protective Enzymes and psbA Gene Expres-sion in Wheat Seedlings under Drought Stress

作　　者：侯鹏飞[1] 马俊青[2] 赵鹏飞[1] 张欢玲[1] 赵会杰[1] 刘华山[1] 赵一丹[1] 汪月霞[1] 

机构地区：[1]河南农业大学生命科学学院,河南郑州450002 [2]河南省林业科学研究院,河南郑州450008

出　　处：《作物学报》2013年第7期1319-1324,共6页Acta Agronomica Sinica

基　　金：国家自然科学基金项目(31000688);河南省教育厅科学技术研究重点项目(13A210487)资助

摘　　要：为了探究外源甜菜碱对干旱胁迫下小麦幼苗的生长调节作用,以优质高产、高抗旱的小麦品种矮抗58为材料,四叶期分别用0.1、1.0和10.0mmolL?1的GB预处理小麦叶片,同时在根部施加30%聚乙二醇(PEG-6000)以模拟干旱环境,研究其对小麦超氧化物歧化酶(SOD),过氧化氢酶(CAT),过氧化物酶(POD),丙二醛(MDA)、超氧阴离子自由基(O???)产生速率、叶绿素含量及相对含水量的影响,并采用Real-timePCR测定叶绿体psbA基因表达水平的变化。结果表明,干旱胁迫明显减少小麦叶片相对含水量和叶绿素含量,降低SOD、CAT及POD活性,提升MDA含量和O???产生速率,抑制psbA基因表达水平,而外施GB具一定浓度效应,在适当浓度下能明显缓解这些胁迫反应,调控干旱胁迫下小麦叶绿体抗氧化酶活性以清除多余活性氧,减缓相对含水量及叶绿素含量的降低,提升psbA基因的表达水平,从而加快受损D1蛋白的周转并提高小麦的抗干旱胁迫能力。With the purpose of revealing the effect of exogenous glycine betaine （GB） on wheat seedlings, Aikang 58 was used as the experimental material, which has the characteristics of high yield and drought resistance. The leaves were sprayed with 0.1, 1.0, and 10.0 mmol L-1 of GB during four-leaf stage, respectively, while the root was applied by 30% polyethylene glycol （PEG-6000） to simulate the drought environment. The effects of exogenous GB treatment on the parameters of superoxide dismu- tase （SOD）, catalase （CAT）, peroxidase （POD） activities, superoxide anion radicals （O~） production rate, malondialdehyde （MDA）, chlorophyll content, and relative water content （RWC） under drought stress were tested three days after treatment. Si- multaneously, the relative transcriptional expression ofpsbA in chloroplast was determined by Real-time PCR assay. The results showed that drought stress obviously decreased the RWC and chlorophyll content of wheat leaves, reduced activities of SOD, CAT, and POD, increased MDA content and the production rate of reactive oxygen species, and suppressed psbA expression. Nevertheless, such stress reactions were alleviated by exogenous GB treatment, and this regulation effect showed a great correla- tion with GB concentration. These results indicated that exogenous GB could remove excess reactive oxygen, and retard the de- crease of RWC and chlorophyll content by regulating antioxidant enzyme activities in wheat chloroplast under drought stress, enhance the transcriptional level ofpsbA gene, accelerate the turnover of D 1 protein in wheat chloroplast, and finally improve the drought resistance in wheat.

关 键 词：小麦 甜菜碱 PSBA基因 干旱胁迫 叶绿体抗氧化酶 

分 类 号：S512.1[农业科学—作物学]