AcoMYB4, anAnanas comosusL. MYB Transcription Factor, Functions in Osmotic Stress through Negative Regulation of ABA Signaling
AcoMYB4, anAnanas comosusL. MYB Transcription Factor, Functions in Osmotic Stress through Negative Regulation of ABA Signaling
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AcoMYB4，Ananas comosusL.
DOI：
10.3390/ijms21165727
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发表时间：
2020-08-01
影响因子：
5.6
通讯作者：
Qin, Yuan
中科院分区：
文献类型：
--
作者：
Chen, Huihuang;Lai, Linyi;Qin, Yuan
干旱和盐胁迫是影响全球农作物生存、发育、分布和产量的主要环境因子。MYB转录因子在植物的生物学过程中起着重要的作用，但菠萝MYB基因的功能尚不清楚。在这项研究中，菠萝MYB转录因子之一，AcoMYB4，分离和表征。结果表明，AcoMYB 4定位于细胞核，其表达受低温、干旱、盐胁迫和激素刺激的诱导，尤其是脱落酸（阿坝）的诱导。在水稻和拟南芥中过量表达AcoMYB 4可增强植物对渗透胁迫的敏感性，导致盐和干旱胁迫下叶片表面气孔数量增加，发芽率降低。AcoMYB4OE的膜氧化指数、游离脯氨酸和可溶性糖含量均降低。相反，由于膜伤害，电解质渗漏和丙二醛（MDA）含量显著增加，表明对干旱和盐胁迫的敏感性更高。此外，AcoMYB 4转基因植株中几种抗氧化酶的表达量和活性均降低，表明转基因植株抗氧化活性较低。此外，在渗透胁迫下，AcoMYB 4的过表达抑制阿坝合成的基因（ABA 1和ABA 2）和阿坝信号转导因子ABI 5的转录负责阿坝合成的减少。这些结果表明AcoMYB4通过减弱细胞阿坝生物合成和信号转导途径负调节渗透胁迫。
Drought and salt stress are the main environmental cues affecting the survival, development, distribution, and yield of crops worldwide. MYB transcription factors play a crucial role in plants' biological processes, but the function of pineapple MYB genes is still obscure. In this study, one of the pineapple MYB transcription factors,AcoMYB4, was isolated and characterized. The results showed thatAcoMYB4is localized in the cell nucleus, and its expression is induced by low temperature, drought, salt stress, and hormonal stimulation, especially by abscisic acid (ABA). Overexpression ofAcoMYB4in rice and Arabidopsis enhanced plant sensitivity to osmotic stress; it led to an increase in the number stomata on leaf surfaces and lower germination rate under salt and drought stress. Furthermore, inAcoMYB4OE lines, the membrane oxidation index, free proline, and soluble sugar contents were decreased. In contrast, electrolyte leakage and malondialdehyde (MDA) content increased significantly due to membrane injury, indicating higher sensitivity to drought and salinity stresses. Besides the above, both the expression level and activities of several antioxidant enzymes were decreased, indicating lower antioxidant activity in AcoMYB4 transgenic plants. Moreover, under osmotic stress, overexpression ofAcoMYB4inhibited ABA biosynthesis through a decrease in the transcription of genes responsible for ABA synthesis (ABA1andABA2) and ABA signal transduction factorABI5. These results suggest that AcoMYB4 negatively regulates osmotic stress by attenuating cellular ABA biosynthesis and signal transduction pathways.