The rice OsDIL gene plays a role in drought tolerance at vegetative and reproductive stages
The rice OsDIL gene plays a role in drought tolerance at vegetative and reproductive stages
复制标题
DOI：
10.1007/s11103-013-0057-9
复制
发表时间：
2013-06-01
影响因子：
5.1
通讯作者：
Ma, Hong
中科院分区：
文献类型：
--
作者：
Guo, Changkui;Ge, Xiaochun;Ma, Hong
干旱是限制全球水稻和其他作物繁殖产量的关键因素之一。然而，水稻在干旱胁迫下生殖发育的分子机制尚不清楚。为了探索干旱条件下水稻生殖发育的潜在基因功能，我们从微阵列数据中发现了一个干旱诱导基因——Oryza sativa drought - induced LTP (OsDIL)，该基因编码一种脂质转移蛋白。OsDIL主要在花药中表达，主要响应非生物胁迫，包括干旱、寒冷、NaCl和与胁迫相关的植物激素ABA。与野生型相比，过表达osdil的转基因水稻在营养发育过程中对干旱胁迫的耐受性更强，在生殖期干旱处理下，绒毡层缺陷和花药囊缺陷较少。干旱响应基因RD22、SODA1、bZIP46和POD以及ABA合成基因ZEP1的表达量在osdill过表达系中上调，而ABA降解基因ABAOX3的表达量下调。此外，OsDIL的过表达减轻了干旱对花药发育基因（OsC4、CYP704B2和OsCP1）的下调，为干旱条件下支持花粉育性提供了机制。过表达OsDIL显著增强了转基因水稻在生殖发育过程中的抗旱性，而在正常条件下无表型变化或产量损失。因此，OsDIL基因是作物适应不利环境的优良遗传改良候选基因。
Drought is one of the critical factors limiting reproductive yields of rice and other crops globally. However, little is known about the molecular mechanism underlying reproductive development under drought stress in rice. To explore the potential gene function for improving rice reproductive development under drought, a drought induced gene, Oryza sativa Drought-Induced LTP (OsDIL) encoding a lipid transfer protein, was identified from our microarray data and selected for further study. OsDIL was primarily expressed in the anther and mainly responsive to abiotic stresses, including drought, cold, NaCl, and stress-related plant hormone abscisic acid (ABA). Compared with wild type, the OsDIL-overexpressing transgenic rice plants were more tolerant to drought stress during vegetative development and showed less severe tapetal defects and fewer defective anther sacs when treated with drought at the reproductive stage. The expression levels of the drought-responsive genes RD22, SODA1, bZIP46 and POD, as well as the ABA synthetic gene ZEP1 were up-regulated in the OsDIL-overexpression lines but the ABA degradation gene ABAOX3 was down-regulated. Moreover, overexpression of OsDIL lessened the down-regulation by drought of anther developmental genes (OsC4, CYP704B2 and OsCP1), providing a mechanism supporting pollen fertility under drought. Overexpression of OsDIL significantly enhanced drought resistance in transgenic rice during reproductive development, while showing no phenotypic changes or yield penalty under normal conditions. Therefore, OsDIL is an excellent candidate gene for genetic improvement of crop yield in adaption to unfavorable environments.