Arabidopsis WRKY2 transcription factor mediates seed germination and postgermination arrest of development by abscisic acid
Arabidopsis WRKY2 transcription factor mediates seed germination and postgermination arrest of development by abscisic acid
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DOI：
10.1186/1471-2229-9-96
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发表时间：
2009-07-22
影响因子：
5.3
通讯作者：
Yu, Diqiu
中科院分区：
文献类型：
--
作者：
Jiang, Wenbo;Yu, Diqiu
背景：植物WRKY DNA结合转录因子是某些发育过程中的关键调控因子。许多研究表明WRKY基因可能介导种子萌发和萌发后生长。然而，目前还不清楚WRKY基因是否介导ABA依赖的种子萌发和萌发后growth arrest.Results：为了直接确定拟南芥WRKY 2转录因子在ABA依赖的种子萌发和萌发后生长停滞过程中的作用，我们分离了T-DNA插入突变体。WRKY 2的两个独立的T-DNA插入突变体仅在种子萌发和萌发后早期生长期间对阿坝反应过敏。wrky 2突变体显示ABI 5和ABI 3的表达延迟或降低，但Em 1和Em 6的表达增加或延长。wrky 2突变体和野生型显示miR 159及其靶基因MYB 33和MYB 101的表达水平相似。对ABA不敏感突变体abi 5 -1、abi 3 -1、aba 2 -3和aba 3 -1中WRKY 2表达水平的分析进一步表明，ABA诱导的WRKY 2在萌发和萌发后早期生长过程中的积累需要ABI 5、ABI 3、ABA 2和ABA 3。wrky 2突变体在种子萌发和萌发后早期幼苗建立期间的阿坝超敏性可归因于ABI 5、ABI 3和ABI 5诱导突变体中的Em 1和Em 6。WRKY 2介导的阿坝反应不依赖于miR 159及其靶基因MYB 33和MYB 101。ABI 5、ABI 3、ABA 2和ABA 3是阿坝诱导WRKY 2基因转录的重要调控因子。我们的研究结果表明，WRKY 2转录因子介导的种子萌发和萌发后发育受阻的阿坝。
Background: Plant WRKY DNA-binding transcription factors are key regulators in certain developmental programs. A number of studies have suggested that WRKY genes may mediate seed germination and postgermination growth. However, it is unclear whether WRKY genes mediate ABA-dependent seed germination and postgermination growth arrest.Results: To determine directly the role of Arabidopsis WRKY2 transcription factor during ABA-dependent seed germination and postgermination growth arrest, we isolated T-DNA insertion mutants. Two independent T-DNA insertion mutants for WRKY2 were hypersensitive to ABA responses only during seed germination and postgermination early growth. wrky2 mutants displayed delayed or decreased expression of ABI5 and ABI3, but increased or prolonged expression of Em1 and Em6. wrky2 mutants and wild type showed similar levels of expression for miR159 and its target genes MYB33 and MYB101. Analysis of WRKY2 expression level in ABA-insensitive and ABA-deficient mutants abi5-1, abi3-1, aba2-3 and aba3-1 further indicated that ABA-induced WRKY2 accumulation during germination and postgermination early growth requires ABI5, ABI3, ABA2 and ABA3.Conclusion: ABA hypersensitivity of the wrky2 mutants during seed germination and postgermination early seedling establishment is attributable to elevated mRNA levels of ABI5, ABI3 and ABI5-induced Em1 and Em6 in the mutants. WRKY2-mediated ABA responses are independent of miR159 and its target genes MYB33 and MYB101. ABI5, ABI3, ABA2 and ABA3 are important regulators of the transcripts of WRKY2 by ABA treatment. Our results suggest that WRKY2 transcription factor mediates seed germination and postgermination developmental arrest by ABA.