摘要
[目的]探讨弱光胁迫对烟草幼苗抗氧化系统及相关基因表达的影响,为后续开展烟草遗传改良提供科学依据。[方法]以自然光(12000 lx)为对照(CK),设T1(7500 lx)、T2(4500 lx)和T3(2500 lx)3个弱光胁迫处理,于烟苗生长至大十字期时随机取样测定不同光照处理下烟草幼苗的抗氧化系统相关指标,利用实时荧光定量PCR(qRT-PCR)检测调控响应光信号内源物质相关基因的差异表达模式,并分析基因表达对胁迫抗性的影响。[结果]一定程度的弱光(7500和4500 lx)胁迫可使烟苗叶片的脯氨酸(Pro)含量上升,可溶性蛋白含量下降,丙二醛(MDA)含量升高,超氧阴离子产生速率提高,超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)活性提高;而重度弱光(2500 lx)胁迫导致抗氧化酶活性大幅度下降,证明重度弱光导致烟苗生长过弱,其体内的防御酶系统不足以抵抗逆境胁迫。在此过程中,烟草生长素早期反应基因GH3.6、过氧化物酶类似物基因peroxidase P7-like和细胞色素基因P450的表达均在轻度弱光(7500 lx)胁迫时下调,在重度弱光(2500 lx)胁迫时进一步下调;抗病蛋白基因RGA3在重度弱光胁迫下显著下调(P<0.05)。[结论]一定程度的弱光胁迫能激活烟草幼苗抗氧化系统,抑制幼苗内源物质相关基因的表达,推测其参与了烟草的光信号应激反应。
[Objective]The effect of low light intensity stress on tobacco seedlings antioxidant system and expression of related genes were explored to provide scientific basic for tobacco genetic improvement in the future.[Method]Taking natural light(12000 lx)as control(CK),three low light stress treatments T1(7500 lx),T2(4500 lx)and T3(2500 lx) were set up. Antioxidant system indexes of randomly sample of tobacco seedlings during the big cross period in different light treatments were determined. Then real-time fluorescence quantitative PCR(qRT-PCR)method was used to analyze the expression patterns of genes involved in endogenous substances responding to low light intensity stress in tobacco seedlings. Finally,the influence of gene expressions on stress resistance was also analyzed.[Result]A certain degree of low light stress(7500 and 4500 lx)initiated a dramatic increase of the proline(Pro)and malonaldehyde(MDA)contents in tobacco leaves,superoxide anion production rate and antioxidant enzyme activity,including superoxide dismutase (SOD),peroxidase(POD)and catalase(CAT),while a decrease of soluble protein content. However,serious stress(2500 lx) led to antioxidant enzyme activity decrease to a very low level,which proved that serious light stress led to the weak growth of the seeding,and the internal defensive enzyme system was insufficient to resist stress. In this process,the ex- pression of auxin early response gene GH3.6,peroxidase analog gene peroxidase P7-like and cytochrome gene P450 were all down-regulated under mild low light stress(7500 lx),further down-regulated under severe low light stress(2500 lx), and disease resistance protein(RGA3)was down-regulated significantly under severe low light stress(P<0.05).[Conclu- sion]The results show that a certain degree of low light stress activates tobacco seedlings antioxidant system and inhibits the expression of these genes,which might be involved in the light signal stress response in tobacco.
作者
关晓溪
隋常玲
胡海军
吴亚男
吴燕
GUAN Xiao-xi;SUI Chang-ling;HU Hai-jun;WU Ya-nan;WU Yan(School of Biological and Agricultural Science and Technology,Zunyi Normal College,Zunyi,Guizhou 563000,China)
出处
《南方农业学报》
CAS
CSCD
北大核心
2019年第5期957-963,共7页
Journal of Southern Agriculture
基金
国家重点研发计划项目(2018YFD0200509)
贵州省科技计划重点项目(黔科合支撑〔2018〕20104)
贵州省教育厅青年人才成长项目(黔教合KY字〔2016〕261)
遵义市科技局联合科技研发资金项目(遵市科合计〔2018〕10号)
关键词
烟草幼苗
弱光胁迫
生长发育
基因表达
tobacco seeding
low light intensity stress
development and growth
gene expression
作者简介
关晓溪(1986-),博士,副教授,主要从事设施栽培生理与分子生物学研究工作,E-mail:guanxiaoxi1208@163.com.
