The ABSCISIC ACID INSENSITIVE 3 (ABI3) gene is modulated by farnesylation and is involved in auxin signaling and lateral root development in Arabidopsis
The ABSCISIC ACID INSENSITIVE 3 (ABI3) gene is modulated by farnesylation and is involved in auxin signaling and lateral root development in Arabidopsis
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DOI：
10.1046/j.1365-313x.2003.01707.x
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发表时间：
2003-04-01
期刊：
影响因子：
7.2
通讯作者：
McCourt, P
中科院分区：
文献类型：
--
作者：
Brady, SM;Sarkar, SF;McCourt, P
遗传筛选已经确定了一些基因，调节脱落酸（阿坝）的反应在拟南芥。使用抑制筛选和双突变体分析的组合，我们已经确定了这些阿坝反应位点的遗传关系。基于在外源阿坝存在下的萌发，ABI1和ABI2磷酸酶在ERA 1法尼基转移酶处或上游起作用，ABI3和ABI5转录因子在ERA 1处或下游起作用。与ABI3和ABI5相反，ABI4转录因子似乎作用于ERA1或其上游。基于报告基因构建体，ERA1对ABI3的上游调控至少部分发生在转录水平，表明这种脂质修饰是减弱ABI3表达所必需的。类似的实验还表明，ABI3是生长素诱导的侧根原基。与此相关的是，功能丧失的abi3等位基因在生长素和生长素运输抑制剂存在下表现出降低的侧根反应性，而era1突变体具有增加的侧根数量。这些结果表明，通过阿坝响应萌发筛选鉴定的基因，如ERA1和ABI 3在拟南芥中具有生长素作用的可能性。
Genetic screens have identified a number of genes that regulate abscisic acid (ABA) responsiveness in Arabidopsis . Using a combination of suppressor screens and double mutant analysis, we have determined a genetic relationship for a number of these ABA response loci. Based on germination in the presence of exogenous ABA, the ABI1 and ABI2 phosphatases act at or upstream of the ERA1 farnesyl transferase and the ABI3 and ABI5 transcription factors act at or downstream of ERA1 . In contrast with ABI3 and ABI5 , the ABI4 transcription factor appears to act at or upstream of ERA1 . Based on reporter gene constructs, the upstream regulation of ABI3 by ERA1 occurs at least partially at the level of transcription, suggesting that this lipid modification is required to attenuate ABI3 expression. Similar experiments also indicate that ABI3 is auxin inducible in lateral root primordia. Related to this, loss-of-function abi3 alleles show reduced lateral root responsiveness in the presence of auxin and an auxin transport inhibitor, and era1 mutants have increased numbers of lateral roots. These results suggest the possibility that genes identified through ABA responsive germination screens such as ERA1 and ABI3 have functions in auxin action in Arabidopsis .