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

知识价值。在自然环境中，红蓝光调节着幼苗的去黄化和气孔开度。将光感知与去黄化和气孔打开反应联系起来的信号转导级联在很大程度上仍然未知，对红色和蓝色（hrb）突变体的超敏反应尤其令人感兴趣。hrb突变体在红蓝光下具有短的下胚轴表型。草本突变体也更耐脱水，表现出较少的水分流失和蓝光调节的气孔开度。HRB1基因已被克隆，hrb2和hrb3突变已分别定位于染色体2和4。HRB1是一种核zz型锌指蛋白，与磷酸酶7或PP7相互作用，PP7是一种核蓝光信号的正调节因子。HRB1在体内被磷酸化，主要以去磷酸化的形式参与蛋白质复合体。本项目的目的是研究蓝光下HRB1和PP7在去黄化和气孔开度调控中的作用及其相互作用。这些遗传和生化相互作用的研究将为HRB1的功能和光信号机制的网络结构提供新的见解。更广泛的影响。这项研究将为本科生、研究生和博士后提供获得重要研究经验的机会，并培养他们批判性地分析和解决科学问题的能力。一个多元化的本科生群体将包括非裔美国人和西班牙裔美国人，他们来自学术课程和校园范围内的生命科学暑期本科生研究项目。为本科生设计了从生理学、遗传学到分子学的具体训练计划。该项目还将通过在小型和研究有限的本科院校举办研讨会，以及在这些院校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，拟议的研究将开辟新的可能性，通过控制气孔功能，从而通过蒸腾作用吸收二氧化碳和水分损失来设计植物，使其在干燥中存活下来。

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.