PDF(Pubmed)
Abstract：
The transcription factor GT2-LIKE 1 (GTL1) has been implicated in orchestrating a transcriptional network of diverse physiological, biochemical, and developmental processes. In response to water-limiting conditions, GTL1 is a negative regulator of stomatal development, but its potential rolein other water-deficit responses is unknown. We hypothesized that GTL1 regulates transcriptome changes associated with drought tolerance over leaf developmental stages. To test the hypothesis, gene expression was profiled by RNA-seq analysis in emerging and expanding leaves of wild-type and a drought-tolerant gtl1-4 knockout mutant under well-watered and water-deficit conditions. Our comparative analysis of genotype-treatment combinations within leaf developmental age identified 459 and 1073 differentially expressed genes in emerging and expanding leaves, respectively, as water-deficit responsive GTL1-regulated genes. Transcriptional profiling identified a potential role of GTL1 in two important pathways previously linked to drought tolerance: flavonoid and polyamine biosynthesis. In expanding leaves, negative regulation of GTL1 under water-deficit conditions promotes biosynthesis of flavonoids and anthocyanins that may contribute to drought tolerance. Quantification of polyamines did not support a role for GTL1 in these drought-responsive pathways, but this is likely due to the complex nature of polyamine synthesis and turnover. Our global transcriptome analysis suggests that transcriptional repression of GTL1 by water deficit allows plants to activate diverse pathways that collectively contribute to drought tolerance.
摘要：
转录因子GT2-LIKE1（GTL1）参与了多种生理，生物化学，和发展过程。为了应对水限制条件，GTL1是气孔发育的负调控因子,但其潜在的rolein其他缺水反应是未知的。我们假设GTL1在叶片发育阶段调节与耐旱性相关的转录组变化。为了检验假设，在水分充足和缺水条件下，通过RNA-seq分析在野生型和耐旱gtl1-4敲除突变体的新叶片和扩展叶片中对基因表达进行了分析。我们对叶片发育年龄内的基因型处理组合的比较分析确定了459和1073在新兴和扩张叶片中差异表达的基因，分别,作为缺水响应GTL1调节基因。转录谱分析确定了GTL1在先前与耐旱性相关的两个重要途径中的潜在作用：类黄酮和多胺生物合成。在不断扩大的叶子中，在缺水条件下GTL1的负调节促进黄酮类化合物和花色苷的生物合成，这可能有助于耐旱性。多胺的定量不支持GTL1在这些干旱响应途径中的作用，但这可能是由于多胺合成和周转的复杂性。我们的全球转录组分析表明，水分亏缺对GTL1的转录抑制使植物能够激活共同促进耐旱性的多种途径。
