Gao Lei, Xiang Cheng-Bin
School of Life Sciences, University of Science and Technology of China, Hefei, Anhui, China.
Plant Mol Biol. 2008 May;67(1-2):125-34. doi: 10.1007/s11103-008-9306-8. Epub 2008 Feb 26.
An Arabidopsis mutant with improved salt tolerant germination was isolated from a T-DNA insertion library and designated as AT6. This mutant also exhibited improved salt tolerance phenotype in later developmental stages. But no apparent difference was observed in response to ABA, GA or ethylene during germination between the mutant and the wildtype. The T-DNA was inserted in the At1g73660 locus that coded for a putative MAPKKK. Genetic and multiple mutant allele analyses confirmed that the knockout of this gene resulted in improved salt tolerance phenotype and provided strong evidence that the genetic locus At1g73660 negatively regulated salt tolerance in Arabidopsis. The At1g73660 was down regulated in response to salt stress in the mutants, which is consistent with its role as a negative regulator. It is therefore hypothesized that the AT1g73660 may serve as one of the off-switches of stress responses that are required for unstressed conditions.
从一个T-DNA插入文库中分离出一个具有耐盐萌发特性的拟南芥突变体，并将其命名为AT6。该突变体在后期发育阶段也表现出耐盐表型。但在萌发过程中，突变体与野生型在对脱落酸（ABA）、赤霉素（GA）或乙烯的反应上未观察到明显差异。T-DNA插入到编码一个假定的促分裂原活化蛋白激酶激酶激酶（MAPKKK）的At1g73660基因座中。遗传分析和多个突变等位基因分析证实，该基因的敲除导致了耐盐表型的改善，并提供了强有力的证据表明At1g73660基因座在拟南芥中对耐盐性起负调控作用。在突变体中，At1g73660基因响应盐胁迫而下调，这与其作为负调控因子的作用一致。因此推测，AT1g73660可能是无胁迫条件下应激反应所需的关闭开关之一。
