过量表达OsYUC2转基因水稻幼苗对干旱和H2O2胁迫的生长生理应答

OsYUC2基因是控制水稻生长素合成的关键基因家族OsYUCs成员之一。本研究以过量表达pUbi-OsYUC2-GUS转基因水稻(G3株系)和野生型水稻(WT,Oryza sativa L .sppj.aponica,v.nipponbare,日本晴)为材料,分别比较了二者在干旱和 H2O2 胁迫下生长生理的变化。结果显示,20%PEG-6000和0.06% H2O2 处理条件下,G3的株高、初生根上侧根的长度(特别是不定根上侧根的数量和长度)都大于WT的;而G3的MDA和H2O2积累量则都少于WT的。与对照组比,PEG和H2O2处理后G3根系的GUS活性都降低且由均匀分布变为梯度分布,说明PEG和H2O2影响OsYUC2基因的表达部位和空间分布。相同处理条件下,G3根系与DR5-GUS转基因水稻根系GUS活性和分布样式的变化类似,显示PEG和H2O2减少生长素的积累并影响其梯度分布。OsYUC2过量表达在一定程度上缓解了由于PEG和 H2O2 胁迫导致生长素减少引起的伤害,转基因水稻幼苗的抗逆水平有所提高。

Response of Growth and Physiological Indicators in OsYUC2-overexpressing Rice Seedlings to Drought and H2O2 Stress

OsYUC2 gene is a member of OsYUCs gene familythat controls auxin biosynthesis in rice. In this paper, we investigated the changes of growth and physiological indicators between transgenic rice plants (G3 lines which containing pUbi-OsYUC2-GUS fragment) and wild-type plants (Oryza sativa L. spp. japonica,v. nipponbare) in response to drought-or H2O2- treatment. The results showed that the plant height and the length of lateral roots at primary root (especially the number and length of lateral roots at adventitious root) of G 3 lines were greater than those in wild-type ones after treating with 20% PEG-6000 and 0.06% H2O2, while the accumulation of MDA and H2 O2 in G 3 lines were both less than that of wildtype rice plants. Compared with the controls, GUS activity in roots of G 3 lines decreased and the activity changed from uniform distribution to gradient distribution after PEG- or H2 O2" treatment, which indicated that PEG and H2 O2 could affect the expression site and spatial distribution of OsYUC2 gene. Meanwhile, the changes of GUS activity and distribution pattern in both G 3 lines roots and DR5-GUS lines roots under the same treatment were consistent, which indicated that PEG and H2O2 reduced auxin accumulation and affected its gradient distribution. In a word,O5YL/C2-Overexpression could alleviate auxin-decreasing damage caused by PEG and H2 O2 stress to a certain extent, and the stress-resistance in transgenic rice seedlings was improved.