Co-transforming bar and CsLEA enhanced tolerance to drought and salt stress in transgenic alfalfa (Medicago sativa L.)
Co-transforming bar and CsLEA enhanced tolerance to drought and salt stress in transgenic alfalfa (Medicago sativa L.)
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共转化棒和 CsLEA 增强了转基因苜蓿 (Medicago sativa L.) 对干旱和盐胁迫的耐受性
DOI：
10.1016/j.bbrc.2016.02.067
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发表时间：
2016
影响因子：
3.1
通讯作者：
Wang Yanrong
中科院分区：
文献类型：
--
作者：
Zhang Jiyu;Duan Zhen;Zhang Daiyu;Zhang Jianquan;Di Hongyan;Wu Fan;Wang Yanrong
干旱和高盐度是制约紫花苜蓿产量的两大非生物因素。将荒漠牧草Cleistgenes songorica中的脱水蛋白CsLEA转化到紫花苜蓿(MedicagosativaL.)以bar1基因为选择标记，通过农杆菌介导法进行转化，并对转基因植株的耐旱性和耐盐性进行了鉴定。经BASTA筛选，119个转化子中有39个转化子为阳性，进一步用聚合酶链式反应和逆转录-聚合酶链式反应进行分子鉴定。表型观察表明，经过15d的干旱胁迫和10d的盐胁迫后，转基因植株的生长情况好于野生型(WT)植株：野生型紫花苜蓿叶片变黄，而转基因紫花苜蓿叶片只萎靡不振；复水后，转基因植株恢复到正常状态，但野生型植株无法恢复。干旱和盐胁迫下的生理生化指标测定表明，转基因植株叶片中的Na+含量相对较低，这将减轻有毒离子的影响。此外，转基因植株能够保持较高的相对含水量(RWC)，较高的地上部生物量，较少的光系统变化，减轻膜伤害，以及较低的渗透胁迫伤害水平。这些结果表明，过表达CsLEA基因可以提高转基因紫花苜蓿的抗旱性和耐盐性；此外，在基因组中携带BarA基因可能会增加除草剂的抗性。
Drought and high salinity are two major abiotic factors that restrict alfalfa productivity. A dehydrin protein, CsLEA, from the desert grassCleistogenes songoricawas transformed into alfalfa (MedicagosativaL.) viaAgrobacterium-mediated transformation using thebargene as a selectable marker, and the drought and salt stress tolerances of the transgenic plants were assessed. Thirty-nine of 119 transformants were positive, as screened by Basta, and further molecularly authenticated using PCR and RT-PCR. Phenotype observations revealed that the transgenic plants grew better than the wild-type (WT) plants after 15d of drought stress and 10d of salt stress: the leaves of WT alfalfa turned yellow, whereas the transgenic alfalfa leaves only wilted; after rewatering, the transgenic plants returned to a normal state, though the WT plants could not be restored. Evaluation of physiologic and biochemical indices during drought and salt stresses showed a relatively lower Na+content in the leaves of the transgenic plants, which would reduce toxic ion effects. In addition, the transgenic plants were able to maintain a higher relative water content (RWC), higher shoot biomass, fewer photosystem changes, decreased membrane injury, and a lower level of osmotic stress injury. These results demonstrate that overexpression of theCsLEAgene can enhance the drought and salt tolerance of transgenic alfalfa; in addition, carrying thebargene in the genome may increase herbicide resistance.