%0 Journal Article
%T 过表达GH3-5提高拟南芥抗旱的分子机制
%A 刘晓东
%A 李月
%A 王若仲
%A 代培红
%A 刘超
%A 石书兵
%J 南京农业大学学报
%D 2016
%R 10.7685/jnau.201604019
%X [目的] 拟南芥GH3-5和GH3-6基因属于生长素早期应答基因GH3基因家族。GH3-5基因过表达植株gh3.5-1D和GH3-6基因过表达植株dfl1-D都表现出生长素响应缺失的表型,然而与野生型对照相比两者的抗旱能力却完全相反。研究GH3-5基因的抗旱机制,将能解释两者抗旱表型完全相反的原因。[方法] 采用液相色谱-质谱联用技术测定了干旱胁迫后gh3.5-1D、dfl1-D及其对应野生型中水杨酸的含量,同时检测了gh3.5-1D/NahG和gh3.5-1D/npr1两种双突变体的抗旱性。[结果] 与野生型相比,干旱胁迫后dfl1-D中水杨酸(SA)的含量没有差异,而gh3.5-1D中SA的含量增加了1倍。进一步研究发现,gh3.5-1D较高的抗旱能力在gh3.5-1D/NahG双突变体中丧失,而在gh3.5-1D/npr1双突变体中没有明显变化。[结论] 水杨酸的过量积累是gh3.5-1D抗旱性发生逆转的原因,然而这种SA赋予的抗旱性可能并不依赖NPR1。</br>[Objectives] GH3-5 and GH3-6 belong to the same gene family of GH3 that are early auxin-responsive genes in Arabidopsis. Both of gh3.5-1D and dfl1-D,the over expression lines of GH3-5 and GH3-6 respectively,exhibit similar auxin-related defects. However,their phenotypes of drought tolerance are completely opposite compared to wildtype. Here we explored the underlying mechanism of drought tolerance conferred by overexpression of GH3-5 and explained the difference of drought response between gh3.5-1D and dfl1-D.[Methods] The level of salicylic acid (SA) was measured by liquid chromatography-mass spectrometry. Drought tolerance was tested in SA deficient and insensitive background using gh3.5-1D/NahG and gh3.5-1D/npr1.[Results] We found that SA levels before and after drought stress in dfl1-D were comparable to those in the wild-type respectively. In contrast,we found that gh3.5-1D accumulated one more fold of SA than the corresponding wild types after drought stress. Further study found that drought tolerance in gh3.5-1D was compromised in gh3.5-1D/NahG but not in gh3.5-1D/npr1.[Conclusions] Drought tolerance conferred by overexpression of GH3.5 depends on NPR1-independent salicylic acid signaling pathway
%K GH3
%K 抗旱性
%K 水杨酸
%K 生长素&lt
%K /br&gt
%K GH3
%K drought tolerance
%K salicylic acid
%K auxin
%U http://nauxb.njau.edu.cn/oa/darticle.aspx?type=view&id=201604005