Stimulus-reversible Co-repression in Regulation of a Plant bZIP Factor

0091927 Jonathan Arias生物和工业活动导致有机毒素在环境中积累。 通过改变碱性/亮氨酸拉链（bZIP）转录因子的活性，增加核解毒基因的转录速率，提供针对这种“异生素应激”剂的细胞保护。 已经阐明了动物和酵母的外源性响应bZIP因子的关键结构和调控特征。 相比之下，对它们在植物中的功能对应物知之甚少。 这项研究的长期目标是了解涉及烟草bZIP因子TGA 1a的转录如何受到细胞和应激信号的调节。 最近研究表明，2，4-二氯苯氧乙酸诱导的外源性胁迫可刺激TGA 1a的DNA结合和反式激活功能。 一个核TGA 1a结合蛋白称为p120，具有共阻遏物的特性，强烈涉及这些转录活动的应激反应调节。 PI的实验室将通过对其克隆基因的体内功能研究来研究p120辅阻遏物的作用模式。 TGA 1a及其同源as-1型顺式元件参与了许多植物解毒和寄主防御基因的调控。 因此，阐明这一转录反应途径的分子基础对于推进细胞解毒过程的基础知识，以及开发有效的遗传策略来操纵植物的天然保护基因是重要的。 由于外源毒素在作物中积累，并保留显着的潜在活性，研究旨在了解植物的解毒途径的转录控制可能对人类健康有重要意义。

0091927 Jonathan AriasBiotic and industrial activities result in the environmental accumulation of organic toxins. Cellular protection against such "xenobiotic stress" agents is afforded by increasing the rate of transcription of nuclear detoxification genes, through changes in the activity of basic/leucine-zipper (bZIP) transcription factors. Key structural and regulatory features of xenobiotic-responsive bZIP factors of animals and yeast have been elucidated. By comparison, less is known about their functional counterparts in plants. The long-term goal of this research is to understand how transcription involving a tobacco bZIP factor termed TGA1a is regulated by cellular and stress cues. Recently it has been shown that xenobiotic stress induced by 2,4-dichlorophenoxyacetic acid can stimulate DNA-binding and trans-activation functions of TGA1a. A nuclear TGA1a-binding protein termed p120, with properties of a co-repressor, is strongly implicated in stress-responsive regulation of these transcription activities. The PI's laboratory will investigate the mode of action of the p120 co-repressor, through in vivo functional studies with its cloned gene. TGA1a and its cognate as-1-type cis-elements have been implicated in the regulation of a number of plant detoxification and host-defense genes. Thus, elucidating the molecular basis of this transcriptional response pathway is important for advancing basic knowledge of cellular detoxification processes, and for developing effective genetic strategies to manipulate natural protective genes of plants. Because xenobiotic toxins accumulate in crop plants and retain significant latent activity, research aimed at understanding plant transcriptional control of detoxification pathways may have important implications for human health.