Overexpression of the Brassinosteroid Biosynthetic Gene AtDWF4 in Arabidopsis Seeds Overcomes Abscisic Acid-induced Inhibition of Germination and Increases Cold Tolerance in Transgenic Seedlings
Overexpression of the Brassinosteroid Biosynthetic Gene AtDWF4 in Arabidopsis Seeds Overcomes Abscisic Acid-induced Inhibition of Germination and Increases Cold Tolerance in Transgenic Seedlings
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DOI：
10.1007/s00344-010-9150-3
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发表时间：
2010-12-01
影响因子：
4.8
通讯作者：
Krishna, Priti
中科院分区：
文献类型：
--
作者：
Divi, Uday K.;Krishna, Priti
类维生素C（BRs）是植物正常生长和发育所必需的，也保护植物免受各种环境胁迫。种子含有相对高水平的BR，并且BR与胚胎图案化和萌发有关。目前尚不清楚种子中的BR水平如何影响早期幼苗的发芽、生长和胁迫耐受性。为了评估这一点，BR生物合成基因AtDWF4在拟南芥种子特异性油质蛋白启动子的控制下过表达。与野生型和载体对照幼苗相比，所得到的转基因幼苗可以克服外源脱落酸（阿坝）引起的发芽抑制，并且幼苗更耐受冷胁迫。COR15A，一个冷响应基因与建立的功能，在耐寒性，转录水平约为2倍，在转基因幼苗比对照幼苗在寒冷条件下。这些结果确立了BR在对抗阿坝对种子萌发的抑制作用和促进早期拟南芥幼苗耐冷胁迫中的作用。
Brassinosteroids (BRs) are essential for proper plant growth and development and also protect plants from a variety of environmental stresses. Seeds contain relatively high levels of BRs, and BRs have been implicated in embryonic patterning and germination. How BR levels in seeds impact germination, growth, and stress tolerance in early seedlings is currently not known. To assess this, the BR biosynthetic gene AtDWF4 was overexpressed in Arabidopsis under the control of a seed-specific oleosin promoter. The resulting transgenic seedlings could overcome inhibition of germination caused by exogenous abscisic acid (ABA) and the seedlings were more tolerant to cold stress compared to wild-type and vector control seedlings. Transcript levels of COR15A, a cold-responsive gene with an established function in cold tolerance, were approximately twofold higher in transgenic seedlings than in control seedlings under cold conditions. These results establish a role for BRs in opposing the inhibitory effects of ABA in seed germination and in promoting cold stress tolerance in early Arabidopsis seedlings.