The Role of the Arabidopsis HYL1 Gene in Hormone Signaling

植物的生长和发育，以及植物对胁迫的反应，是由几种激素协调的。 植物和单个细胞内激素的作用取决于传递激素信号的蛋白质，以引起生物化学和转录变化。该项目的目的是分析拟南芥转座子插入突变，指定hyponastic叶（hyl1），改变植物的反应，同时几种激素。初步证据表明，突变基因编码一种与双链RNA结合的核蛋白。变异植物矮小，开花缓慢，叶子卷曲，种子很少，根生长缓慢，对重力没有正常反应。 突变体植物表现出对生长素和细胞分裂素激素的敏感性降低，并且对激素脱落酸（阿坝）高度敏感。 该项目的遗传和分子实验旨在了解HYL1基因编码的蛋白质如何参与植物对不同激素的感知和反应。这些实验的重要性在于，它们将有助于我们理解植物如何协调它们对冲击其细胞的多种激素信号的反应。 虽然这些实验是在模式植物拟南芥中进行的，但在这样一个系统中获得的知识可以很容易地转移到作物植物中，因为高等植物使用相同或相似的系统来调节生长和胁迫反应。 这些知识将在今后努力提高农业植物在不利条件下保持生产力的能力方面非常重要。

Plant growth and development, as well as plant responses to stress, are orchestrated by several hormones. The action of the hormones within the plant and within individual cells depends on proteins that transmit the hormone signals to evoke both biochemical and transcriptional changes. This project has the objective of analyzing an Arabidopsis transposon insertion mutation, designated hyponastic leaves (hyl1), that alters the plant's responses to several hormones simultaneously. Preliminary evidence suggests that the mutant gene encodes a nuclear protein that binds to double-stranded RNA. Mutant plants are short, slow to flower, have curled leaves, produce few seeds, and have slow-growing roots that do not respond to gravity normally. Mutant plants show a reduced sensitivity to the auxin and cytokinin hormones and are hypersensitive to the hormone abscisic acid (ABA). Genetic and molecular experiments in the project are designed to understand how the protein encoded by the HYL1 gene participates in the plant's perception and response to different hormones. The importance of these experiments is that they will contribute to our understanding of how plants coordinate their responses to the multiple hormone signals that impinge on their cells. Although the experiments are being performed in the model plant Arabidopsis, knowledge gained in such a system can be transferred readily to crop plants because higher plants use the same or similar systems to regulate growth and stress responses. Such knowledge will be very important in future efforts to improve the ability of agricultural plants to maintain productivity under adverse conditions.