LiT:HRB1 and PP7 in de-etiolation and Stomatal Opening

智力上的优点。红光和蓝光在自然环境中调节幼苗的脱黄化和气孔开度。将光的感知与去黄化和气孔开放反应联系起来的信号转导通路在很大程度上仍不清楚，对红蓝(HRB)突变体特别敏感的信号转导通路是人们特别感兴趣的。HRB突变体最初被分离出来是因为它们在红光和蓝光下的下胚轴较短的表型。Hrb突变体也更耐脱水，表现出更少的失水和蓝光调节的气孔开度。Hrb1基因已被克隆，hrb2和hrb3突变分别被定位在第2和第4染色体上。HRB1是一种核ZZ型锌指蛋白，与磷酸酶7或PP7物理上相互作用，PP7是以前在细胞核中发现的蓝光信号的正调控因子。HRB1在体内被磷酸化，主要以去磷酸化的形式参与到蛋白质复合体中。本课题的目的是研究HRB1和PP7在蓝光下叶片脱黄化和气孔开度调控中的作用及其相互作用。对这些遗传和生化相互作用的研究将为了解HRB1的功能和光信号机制的网络结构带来新的见解。这项研究将为本科生、研究生和博士后研究员提供机会，获得重要的研究经验，并培养他们批判性分析和解决科学问题的能力。不同的本科生群体将包括非洲裔美国人和西班牙裔美国人，他们来自学术课程和全校生命科学暑期本科生研究项目。已经为本科生设计了具体的培训计划，范围从生理学、遗传学到分子研究。该项目还将通过在规模较小和研究有限的本科机构举办研讨会以及在这些机构招募学生到明尼苏达大学进行暑期研究来支持本科教育。在更广泛的层面上，拟议的研究将打开新的可能性，通过控制气孔功能，从而控制二氧化碳的吸收和蒸腾作用中的水分损失，使植物在干旱中生存下来。

Intellectual merit. Red and blue light regulate seedling de-etiolation and stomatal aperture in natural environments. The signal transduction cascades that link the perception of light to the de-etiolation and stomatal opening responses are still largely unknown, and hypersensitive to red and blue (hrb) mutants are of particular interest. The hrb mutants were initially isolated for their short hypocotyl phenotype under red and blue light. The hrb mutants are also more resistant to dehydration and show reduced water loss and blue light-regulated stomatal aperture. The HRB1 gene has been cloned and the hrb2 and hrb3 mutations have been mapped to chromosomes 2 and 4, respectively. HRB1 is a nuclear ZZ-type zinc finger protein and physically interacts with phosphatase 7 or PP7, a previously identified positive regulator of blue light signaling in the nucleus. HRB1 is phosphorylated in vivo and is involved in a protein complex mostly in its de-phosphorylated form. The goal of this project is to study the function of HRB1 and PP7 and their interaction in the control of de-etiolation and stomatal aperture under blue light. The studies on these genetic and biochemical interactions will bring novel insights into HRB1 function and the network structure of the light signaling machinery.Broader impacts. This research will provide opportunities for undergraduates, graduate students, and postdoctoral fellows to gain significant research experiences and to develop their ability to critically analyze and solve scientific problems. A diverse group of undergraduates will include African Americans and Hispanics drawn from academic courses and from a campus-wide life science summer undergraduate research program. A specific training plan has been designed for the undergraduates, ranging from physiological, genetic, to molecular studies. This project will also support undergraduate education through seminars at small and research-limited undergraduate institutions and recruitment of students at these institutions to perform summer research at the University of Minnesota. On an even broader level, the proposed studies will open new possibilities to engineer plants to survive desiccation by controlling stomatal function and hence CO2 uptake and the loss of water through transpiration.