ABI5 interacts with abscisic acid signaling effectors in rice protoplasts
ABI5 interacts with abscisic acid signaling effectors in rice protoplasts
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DOI：
10.1074/jbc.m109980200
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发表时间：
2002-01-18
影响因子：
4.8
通讯作者：
Rock, CD
中科院分区：
文献类型：
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作者：
Gampala, SSL;Finkelstein, RR;Rock, CD
脱落酸（ABA）调节种子的成熟、萌发和营养组织对环境胁迫的适应。ABA的作用机制和重叠通路中信号成分的特异性尚不完全清楚。拟南芥ABI5基因（ABA不敏感5）编码一种基本亮氨酸拉链因子，这是种子和营养组织对ABA反应所必需的。通过在水稻原生质体中的瞬时基因表达，我们为ABI5与ABA信号效应因子VP1（胎生1）和ABI1 （ABA不敏感1）的功能相互作用提供了证据。用ABI5 cDNA构建的共转化实验结果表明，aba诱导的小麦Em、拟南芥AtEm6、豆类β - phaseolin和大麦HVA1和HVA22启动子特异性转激活。此外，ABI5与ABA协同作用并共同表达VP1，表明ABI5参与了VP1介导的ABA调控转录。abi5介导的转激活被ABI1 -1（蛋白磷酸酶ABI1的显性负等位基因）和1-丁醇（参与ABA信号传导的磷脂酶D的竞争性抑制剂）的过表达所抑制。镧是一种三价离子，作为ABA信号的激动剂，增强了ABI5的交易激活。这些结果表明，ABI5是植物中保守的ABA信号通路的关键靶点。
Abscisic acid (ABA) regulates seed maturation, germination, and adaptation of vegetative tissues to environmental stresses. The mechanisms of ABA action and the specificity conferred by signaling components in overlapping pathways are not completely understood. The ABI5 gene (ABA insensitive 5) of Arabidopsis encodes a basic leucine zipper factor required for ABA response in the seed and vegetative tissues. Using transient gene expression in rice protoplasts, we provide evidence for the functional interactions of ABI5 with ABA signaling effectors VP1 (viviparous 1) and ABI1 (ABA insensitive 1). Co-transformation experiments with ABI5 cDNA constructs resulted in specific transactivation of the ABA-inducible wheat Em, Arabidopsis AtEm6, bean beta-Phaseolin, and barley HVA1 and HVA22 promoters. Furthermore, ABI5 interacted synergistically with ABA and co-expressed VP1, indicating that ABI5 is involved in ABA-regulated transcription mediated by VP1. ABI5-mediated transactivation was inhibited by overexpression of abi1-1, the dominant-negative allele of the protein phosphatase ABI1, and by 1-butanol, a competitive inhibitor of phospholipase D involved in ABA signaling. Lanthanum, a trivalent ion that acts as an agonist of ABA signaling, potentiated ABI5 transactivation. These results demonstrate that ABI5 is a key target of a conserved ABA signaling pathway in plants.