The genes ABI1 and ABI2 are involved in abscisic acid- and drought-inducible expression of the Daucus carota L. Dc3 promoter in guard cells of transgenic Arabidopsis thaliana (L.) Heynh.
The genes ABI1 and ABI2 are involved in abscisic acid- and drought-inducible expression of the Daucus carota L. Dc3 promoter in guard cells of transgenic Arabidopsis thaliana (L.) Heynh.
复制标题
DOI：
10.1007/s004250050692
复制
发表时间：
2000-05-01
期刊：
影响因子：
4.3
通讯作者：
Rock, CD
中科院分区：
文献类型：
--
作者：
Chak, RKF;Thomas, TL;Rock, CD
ABA INSENSITIVE1(AB11)和AB12基因编码同源的2C型蛋白磷酸酶，在脱落酸(ABA)反应中具有冗余但不同的功能。Northern印迹分析结果表明，ABA和甘露醇诱导的COR47和COR78/LT178/RD29A(COR78)基因在拟南芥abi2突变体中的表达受到严重的抑制。Heynh比abi1中的突变体。此外，ABA+甘露醇处理对COR47基因的表达是相加的；然而，与野生型相比，ABA缺乏的aba1突变体对甘露醇和ABA+甘露醇处理的COR表达降低。这些结果支持这样一种观点，即干旱和脱落酸信号通路是分开的，但却是重叠的。为了便于定量分析组织特异性ABA和脱水反应通路的遗传控制，我们分析了ABA和甘露醇诱导的胡萝卜(Daucus carota L.)DC3启动子：转基因野生型、ABA缺乏的aba1和ABA不敏感的abi1和abi2突变体中的uidA(β-葡萄糖醛酸酶；GUS)嵌合报告基因(DC3-GUS)。DC3启动子引导ABA和甘露醇诱导的GUS在拟南芥保卫细胞中表达，两种处理是相加的。Aba1、abi1和abi2突变体降低了甘露醇对子叶保卫细胞的GUS表达，而abi1和abi2突变体降低了ABA诱导的GUS表达，这与ABA和干旱反应途径重叠一致。叶片提取液的GUS荧光定量分析表明，abi2突变体对外源ABA的响应小于abi1突变体，而abi2突变体对甘露醇的响应大于abi1突变体。我们认为DC3-GUS拟南芥是一个研究组织特异性ABA和干旱信号的简便系统，并认为AB12在COR78和COR47基因表达和保卫细胞DC3-GUS表达方面比AB11发挥更大的功能。
The ABA INSENSITIVE1 (AB11) and AB12 genes encode homologous type-2C protein phosphatases with redundant yet distinct functions in abscisic acid (ABA) responses. Results from Northern blot analysis showed that ABA- and mannitol-inducible expression of the COR47 and COR78/LT178/RD29A (COR78) genes was more impaired in the abi2 mutant of Arabidopsis thaliana (L.) Heynh than in the abi1 mutant. Furthermore, ABA-plus-mannitol treatments were additive towards COR47 gene expression; however, the ABA-deficient aba1 mutant showed reduced COR expression relative to the wild type in response to mannitol and ABA-plus-mannitol treatments. These results support the notion that drought- and ABA-signalling pathways are separate yet overlapping. To facilitate quantitative analysis of the genetic control of tissue-specific ABA- and desiccation-response pathways, we analyzed ABA- and mannitol-inducible expression of a carrot (Daucus carota L.) Dc3 promoter:uidA (beta-glucuronidase; GUS) chimaeric reporter (Dc3-GUS) in transgenic wild-type, ABA-deficient aba1, and ABA-insensitive abi1 and abi2 mutants. The Dc3 promoter directed ABA- and mannitol-inducible GUS expression in Arabidopsis guard cells and the two treatments were additive. The aba1, abi1, and abi2 mutant genotypes had reduced GUS expression in guard cells of cotyledons in response to mannitol, whereas abi1 and abi2 mutants were reduced in ABA-inducible GUS expression, consistent with overlapping ABA- and drought-response pathways. Quantitative fluorometric GUS assays of leaf extracts showed that abi2 mutants responded less to exogenous ABA than did abi1 mutants, and abi2 mutants responded more to mannitol than did abi1 mutants. We conclude that Dc3-GUS Arabidopsis is a tractable system in which to study tissue-specific ABA and drought signalling and suggest that AB12 functions predominantly over AB11 in COR78 and COR47 gene expression and guard-cell Dc3-GUS expression.