Dansana Prasant K, Kothari Kamakshi S, Vij Shubha, Tyagi Akhilesh K
Interdisciplinary Centre for Plant Genomics and Department of Plant Molecular Biology, University of Delhi, South Campus, Benito Juarez Road, New Delhi, 110021, India.
Plant Cell Rep. 2014 Sep;33(9):1425-40. doi: 10.1007/s00299-014-1626-3. Epub 2014 Jun 26.
OsiSAP1, an A20/AN1 zinc-finger protein, confers water-deficit stress tolerance at different stages of growth by affecting expression of several endogenous genes in transgenic rice. Transgenic lines have been generated from rice constitutively expressing OsiSAP1, an A20/AN1 zinc-finger containing stress-associated protein gene from rice, driven by maize UBIQUITIN gene promoter and evaluated for water-deficit stress tolerance at different stages of growth. Their seeds show early germination and seedlings grow better under water-deficit stress compared to non-transgenic (NT) rice. Leaves from transgenic seedlings showed lesser membrane damage and lipid peroxidation under water-deficit stress. Relatively lower rate of leaf water loss has been observed in detached intact leaves from transgenic plants during late vegetative stage. Delayed leaf rolling and higher relative water content were also observed in transgenic plants under progressive water-deficit stress during reproductive developmental stage. Although reduction in grain yield is observed under unstressed condition, the relative water-deficit stress-induced yield losses are lower in transgenic rice vis-à-vis NT plants thereby resulting in yield loss protection. Transcriptome analysis suggests that overexpression of OsiSAP1 in transgenic rice results in altered expression of several endogenous genes including those coding for transcription factors, membrane transporters, signaling components and genes involved in metabolism, growth and development. A total of 150 genes were found to be more than twofold up-regulated in transgenic rice of which 43 genes are known to be involved in stress response. Our results suggest that OsiSAP1 is a positive regulator of water-deficit stress tolerance in rice.
OsiSAP1是一种A20/AN1锌指蛋白，通过影响转基因水稻中几个内源基因的表达，在不同生长阶段赋予其耐旱胁迫耐受性。利用玉米泛素基因启动子驱动的水稻组成型表达OsiSAP1（一种来自水稻的含A20/AN1锌指的胁迫相关蛋白基因），培育出转基因株系，并在不同生长阶段评估其耐旱胁迫耐受性。与非转基因（NT）水稻相比，它们的种子发芽早，幼苗在水分亏缺胁迫下生长更好。水分亏缺胁迫下，转基因幼苗的叶片膜损伤和脂质过氧化程度较低。在营养生长后期，转基因植株离体完整叶片的失水速率相对较低。在生殖发育阶段的渐进性水分亏缺胁迫下，转基因植株还表现出叶片卷曲延迟和相对含水量较高。虽然在非胁迫条件下观察到转基因水稻的籽粒产量有所下降，但与NT植株相比，转基因水稻因水分亏缺胁迫导致的产量损失相对较低，从而实现了产量损失保护。转录组分析表明，转基因水稻中OsiSAP1的过表达导致几个内源基因的表达发生改变，包括那些编码转录因子、膜转运蛋白、信号成分以及参与代谢、生长和发育的基因。共发现150个基因在转基因水稻中上调了两倍以上，其中43个基因已知参与胁迫反应。我们的结果表明，OsiSAP1是水稻耐旱胁迫耐受性的正调控因子。
