Redundant and distinct functions of the ABA response loci ABA-INSENSITIVE(ABI)5 and ABRE-BINDING FACTOR (ABF)3
Redundant and distinct functions of the ABA response loci ABA-INSENSITIVE(ABI)5 and ABRE-BINDING FACTOR (ABF)3
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DOI：
10.1007/s11103-005-8767-2
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发表时间：
2005-09-01
影响因子：
5.1
通讯作者：
Rock, CD
中科院分区：
文献类型：
--
作者：
Finkelstein, R;Gampala, SSL;Rock, CD
脱落酸反应性基因表达受到多种转录因子的调节，包括碱性亮氨酸拉链因子的亚组，其与被称为 ABA 反应性元件的保守顺式作用序列结合。尽管其中一个因子 ABA 不敏感 5 (ABI5) 已通过基因鉴定，但由于其他家族成员的遗传数据缺乏，尚不清楚它们是否具有独特的功能，或者对 ABI5 或彼此是否具有冗余作用。为了测试 ABI5 的潜在冗余，我们鉴定了在瞬时表达系统（ABF3 和 ABF1）中具有最相似效应和相互作用的家族成员，然后对这些位点的功能丧失系进行了表征。 abf1 和 abf3 单基因突变株系对发芽或种子特异性基因表达的影响至多最小，但 abf3 abi5 双突变体增强的 ABA 和胁迫抗性揭示了这些基因在种子和幼苗的多重胁迫反应中的冗余作用。尽管 ABI5、ABF3 和 ABF1 具有一些重叠的作用，但它们似乎在特定阶段相互拮抗地调节彼此的表达。因此，任何一种因子的损失都可以通过其他家族成员表达的增加来部分补偿。
Abscisic acid-responsive gene expression is regulated by numerous transcription factors, including a subgroup of basic leucine zipper factors that bind to the conserved cis-acting sequences known as ABA-responsive elements. Although one of these factors, ABA-insensitive 5 (ABI5), was identified genetically, the paucity of genetic data for the other family members has left it unclear whether they perform unique functions or act redundantly to ABI5 or each other. To test for potential redundancy with ABI5, we identified the family members with most similar effects and interactions in transient expression systems (ABF3 and ABF1), then characterized loss-of-function lines for those loci. The abf1 and abf3 monogenic mutant lines had at most minimal effects on germination or seed-specific gene expression, but the enhanced ABA- and stress-resistance of abf3 abi5 double mutants revealed redundant action of these genes in multiple stress responses of seeds and seedlings. Although ABI5, ABF3, and ABF1 have some overlapping effects, they appear to antagonistically regulate each other's expression at specific stages. Consequently, loss of any one factor may be partially compensated by increased expression of other family members.