《植物生理学报》 2017, 53(10): 1893-1900

AhHDA1对花生毛状根干旱的生理调节作用

苏良辰, 钟钰婷, 李玲^*

华南师范大学生命科学学院, 广东省植物发育生物工程重点实验室, 广州510631

通信作者：李；E-mail: liling502@126.com

摘　要：

为研究AhHDA1在花生(Arachis hypogaea)干旱胁迫响应中的作用, 本文分析了四叶期花生根和叶片在20% (m/V)聚乙二醇6000 (PEG6000)模拟干旱胁迫下AhHDA1和干旱响应基因的表达变化, 发现AhHDA1、AhAREB1和AhNCED1在叶片中分别上调表达至原来的4.3、2.6和10.3倍, 在根中分别下调表达91.1%、87.3%和89.2%。基因表达模式提示AhHDA1可能与脱落酸(ABA)合成和信号传导有关。通过测定干旱胁迫下35S::eGFP、35S::AhHDA1和35S::AhHDA1-RNAi毛状根含水量、ABA含量、抗氧化酶活性、过氧化氢(H₂O₂)含量和丙二醛(MDA)含量, 发现35S::AhHDA1-RNAi毛状根具有较高的抗旱性和抗氧化能力, 35S::AhHDA1-RNAi在干旱胁迫处理后的含水量为75.3%, 脱落酸含量为1.23 μg·g^-1, 均显著低于其他两种毛状根, 表明抑制AhHDA1表达可提高毛状根细胞的抗旱能力。染色质免疫沉淀(ChIP)分析花生根在干旱胁迫下AhNCED1和AhAREB1启动子区域H3K14ac抗体富集度变化情况, 结果表明, AhNCED1和AhAREB1在H3K14位点的乙酰化程度改变分别在转录起始位点(TSS)和近TSS区启动子发生。

关键词：AhHDA1; 毛状根; 干旱; 脱落酸; 花生

收稿：2017-06-23   修定：2017-10-08

资助：国家自然科学基金(31471422)。

Physiological regulation effect of AhHDA1 on peanut hairy roots to drought stress

SU Liang-Chen, ZHONG Yu-Ting, LI Ling^*

Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Sciences, South China Normal University, Guangzhou 510631, China

Corresponding author: LI Ling; E-mail: liling502@126.com

Abstract:

To study the function of AhHDA1 on drought response in peanut (Arachis hypogaea), the expression changes of AhHDA1 and drought-responsing genes have been analyzed in roots and leaves of four-leaf peanuts with 20% (m/V) polyethylene glycol 6000 (PEG6000) treatment, which was simulated as the drought stress condition. The expressions of AhHDA1, AhAREB1 and AhNCED1 in leaves were found to be up-regulated to 4.3, 2.6 and 10.3 folds, respectively, while AhHDA1, AhAREB1 and AhNCED1 in roots were found to be reduced by 91.1%, 87.3% and 89.2%, respectively. The expression pattern implies abscisic acid (ABA) synthesis and signal transduction might be related to AhHDA1. By measuring water content, ABA content, antioxidant enzyme activities, H₂O₂ and malondialdehyde (MDA) contents in 35S::eGFP, 35S::AhHDA1 and 35S::AhHDA1-RNAi hairy roots, 35S::AhHDA1-RNAi hairy roots possessed higher level of drought capacity and antioxidant ability. Water content of 35S::AhHDA1-RNAi hairy roots was 75.3% and ABA content of 35S::AhHDA1-RNAi hairy roots was 1.23 μg·g^-1, which were significantly lower than the other two hairy roots. The inhibition of AhHDA1 expression improved the drought capacity of hairy roots cells. The enriched degree of H3K14ac on AhNCED1 and AhAREB1 promoters in the roots with drought treatment was also analyzed. It showed histone acetylation of AhNCED1 and AhAREB1 changes on H3K14 locus at TSS (transcriptional start site) and near TSS, respectively.

Key words: AhHDA1; hairy root; drought; abscisic acid; peanut