Mutants at the Slender1 locus of barley cv Himalaya. molecular and physiological characterization
Mutants at the Slender1 locus of barley cv Himalaya. molecular and physiological characterization
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DOI：
10.1104/pp.010917
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发表时间：
2002-05-01
期刊：
影响因子：
7.4
通讯作者：
Gubler, F
中科院分区：
文献类型：
--
作者：
Chandler, PM;Marion-Poll, A;Gubler, F
描述了大麦的一个显性矮秆突变体，该突变体类似于其他物种中的显性赤霉素(GA)“不敏感”或“无反应”突变体。突变株胚乳半粒产生α-淀粉酶需要赤霉素GA，其浓度约为WT的100倍。突变体对GA(3)只有轻微的生长反应，即使在很高的浓度下也是如此。然而，当附加矮化时，生长速率在正常浓度范围内对GA3作出响应，尽管仅返回到原始(矮化)伸长速率。遗传研究表明，显性矮秆基因座与SLn1(Slender1)基因座紧密连锁或完全相同。分离到一个与拟南芥GAI/RGA相关的大麦序列，通过对sln1突变体的分析表明，该序列代表了sln1基因座。显性矮秆突变体在该序列中也发生了改变，表明它也是SLn1的等位基因。因此，SLn1的突变产生了完全不同表型的植物；要么是主要显性的、GA“不敏感/无反应”的矮生植物，要么是CA反应似乎是结构性的隐性细长类型。免疫印迹研究表明，在生长的叶片中，SLN1蛋白几乎只定位在叶片伸长区。在SLn1位点的突变体中，SLN1蛋白的丰度和分布存在差异，生物活性气体及其代谢前体和分解代谢产物的数量也发生了较大变化。这些结果表明，在决定叶片伸长速率时，SLN1蛋白和GA含量之间存在动态交互作用。
A dominant dwarf mutant of barley (Hordeum vulgare) that resembles dominant gibberellin (GA) "-insensitive" or "-nonresponsive" mutants in other species is described. alpha-Amylase production by endosperm half-grains of the mutant required GA, at concentrations about 100 times that of the WT. The mutant showed only a slight growth response to GA(3), even at very high concentrations. However, when additionally dwarfed, growth rate responded to GA3 over the normal concentration range, although only back to the original (dwarf) elongation rate. Genetic studies indicated that the dominant dwarf locus was either closely linked or identical to the Sln1 (Slender1) locus. A barley sequence related to Arabidopsis GAI/RGA was isolated, and shown to represent the Sln1 locus by the analysis of sln1 mutants. The dominant dwarf mutant was also altered in this sequence, indicating that it too is an allele at Sln1. Thus, mutations at Sln1 generate plants of radically different phenotypes; either dwarfs that are largely dominant and GA "-insensitive/-nonresponsive," or the recessive slender types in which CA responses appear to be constitutive. Immunoblotting studies showed that in growing leaves, SLN1 protein localized almost exclusively to the leaf elongation zone. In mutants at the Sln1 locus, there were differences in both the abundance and distribution of SLN1 protein, and large changes in the amounts of bioactive GAs, and of their metabolic precursors and catabolites. These results suggest that there are dynamic interactions between SLN1 protein and GA content in determining leaf elongation rate.