A Cotton MYB Transcription Factor, GbMYB5, is Positively Involved in Plant Adaptive Response to Drought Stress
A Cotton MYB Transcription Factor, GbMYB5, is Positively Involved in Plant Adaptive Response to Drought Stress
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棉花 MYB 转录因子 GbMYB5 积极参与植物对干旱胁迫的适应性反应
DOI：
10.1093/pcp/pcv019
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发表时间：
2015-05-01
影响因子：
4.9
通讯作者：
Zhang, Baolong
中科院分区：
文献类型：
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作者：
Chen, Tianzi;Li, Wenjuan;Zhang, Baolong
干旱胁迫对植物生长产生负面影响，并限制植物生产力。在植物对干旱胁迫的反应中起作用的基因对于耐旱作物的发育是必不可少的。在这里，我们报告了一个R2R3型MYB转录因子基因在海岛棉，GbMYB 5，赋予棉花和转基因烟草的耐旱性。GbMYB5基因沉默降低了棉花幼苗对干旱胁迫的耐受性，使复水后的恢复成活率从野生型（WT）的90%降低到50%。在干旱胁迫下，沉默GbMYB 5基因降低了棉花脯氨酸含量和抗氧化酶活性，增加了丙二醛（MDA）含量。干旱诱导基因NCED3、RD22和RD26的表达水平不受GbMYB 5沉默的影响。然而，GbMYB5过表达烟草株系表现出对阿坝的敏感性，提高了存活率，并降低了干旱胁迫下的失水率。此外，转基因烟草的气孔大小和气孔开放率也明显降低。在干旱胁迫下，GbMYB5基因的过表达促进了脯氨酸和抗氧化酶的积累，同时降低了MDA的产生。在干旱胁迫下，GbMYB 5过表达烟草中抗氧化基因SOD、CAT和GST、多胺合成基因ADC 1和SAMDC、胚胎发育后期丰富蛋白编码基因ERD10 D以及干旱响应基因NCED3、BG和RD26的转录水平普遍高于WT。总的来说，我们的数据表明，GbMYB 5是积极参与植物适应干旱胁迫的反应。
Drought stress negatively affects plant growth and limits plant productivity. Genes functioning in plant responses to drought stress are essential for the development of drought-tolerant crops. Here, we report that an R2R3-type MYB transcription factor gene in Gossypium barbadense, GbMYB5, confers drought tolerance in cotton and transgenic tobacco. Virus-induced gene silencing of GbMYB5 compromised the tolerance of cotton plantlets to drought stress and reduced the post-rewatering water recovery survival rate to 50% as compared with the 90% survival rate in the wild type (WT). Silencing GbMYB5 decreased proline content and antioxidant enzyme activities and increased malondialdehyde (MDA) content in cotton under drought stress. The expression levels of drought-inducible genes NCED3, RD22 and RD26 were not affected by the silencing of GbMYB5. However, GbMYB5-overexpressing tobacco lines displayed hypersensitivity to ABA and improved survival rates as well as reduced water loss rates under drought stress. Furthermore, stomatal size and the rate of opening of stomata were markedly decreased in transgenic tobacco. The overexpression of GbMYB5 enhanced the accumulation of proline and antioxidant enzymes while it reduced production of MDA in transgenic tobacco as compared with the WT under drought stress. The transcript levels of the antioxidant genes SOD, CAT and GST, polyamine biosynthesis genes ADC1 and SAMDC, the late embryogenesis abundant protein-encoding gene ERD10D and drought-responsive genes NCED3, BG and RD26 were generally higher in GbMYB5-overexpressing tobacco than in the WT under drought stress. Collectively, our data suggested that GbMYB5 was positively involved in the plant adaptive response to drought stress.