Genomic Analysis of Leaf Cuticle Development and Functional Diversity in Maize

迈克尔·戈尔（康奈尔大学）；迈克尔·斯坎伦（康奈尔大学）；主要合作者Alisa Huffaker（加州大学圣地亚哥分校）和Andrew French（美国农业部/农业研究局干旱土地农业研究中心）保护作物免受疾病和不利生长条件的侵害是实现可持续粮食生产的关键。角质层是植物叶和茎外表面的蜡状防水层，在防止水分流失方面起着至关重要的作用。这也是植物首先与大多数昆虫和疾病相互作用的地方。因此，角质层在保持植物健康的同时防止它们在微风中干燥是很重要的。虽然许多先前的项目已经对角质层的组成、发育和功能做出了贡献，但很少有项目关注谷类作物的成叶，其角质层对这些关键作物的农业生产性能有重大影响。该项目将发现控制玉米角质层发育和功能的基因，评估改善叶片角质层的潜力，以帮助生产更具耐旱性和抗病性的作物，并开发指导这些工作的工具。以往的研究已经为了解植物角质层的生物发生和功能奠定了基础，但很少有研究集中在玉米等具有重要经济意义的谷类作物的成叶上，而且还没有研究转化为作物改良。本项目将分析成年玉米叶片角质层的生物发生及其遗传基础，阐明由遗传决定的角质层变异对玉米抗旱性和病原菌渗透的影响。第一个目标是将表皮基因表达的全基因组分析与整个发育过程中角质层结构、组成和功能的变化联系起来。第二个目标是通过全基因组关联研究（GWAS）确定控制成年叶片角质层蒸发（CE）速率的位点。第三个目标是分析角质层功能多样性选择的玉米品系，以阐明角质层特征（组织学、超微结构和组成）、角质层作为水分流失和病原体渗透屏障的功能以及耐旱性之间的关系。第四个目标是通过网络分析来阐明基因表达、角质层组成和角质层功能之间的关系。这一最终目标是确定关键的遗传调控因子，并在系统水平上了解成年玉米叶片角质层生物发生和功能的遗传基础。项目成果将包括关于成年玉米叶片角质层发育及其遗传调控的新见解，角质层修饰对玉米抗旱性和病原体感染影响的新知识，以及指导此类修饰的遗传工具。项目成果和数据将通过多种开放获取出版物、位于http://labs.biology.ucsd.edu/smith/的项目网站和三个长期存储库进行交流：NCBI短读档案（http://www.ncbi.nlm.nih.gov/sra）、Maize GDB （http://www.maizegdb.org/）和一个由加州大学圣地亚哥分校图书馆托管的交互式数据库（http://library.ucsd.edu/dc）。参与这个项目将提供跨学科的培训机会，为处于不同教育阶段的年轻科学家进入未来的科学队伍做好准备。它还将扩大对科学的参与，让所有院校的大约120名本科生参与其中，重点关注那些事先很少获得研究机会和/或对科学职业机会有认识的学生。

CoPIs Michael Gore (Cornell University); Michael Scanlon (Cornell University); and Isabel Molina (Algoma University)Key Collaborators Alisa Huffaker (UCSD) and Andrew French (USDA/ARS Arid Land Agricultural Research Center)Protecting crop plants from diseases and adverse growing conditions is key to achieving sustainable food production. The cuticle is a waxy, water-proof layer on the outer surfaces of plant leaves and stems that plays a vital role in preventing water loss. It is also where plants first interact with most insects and diseases. Therefore, the cuticle is important to keep plants healthy while preventing them from drying out in the breeze. While many prior projects have contributed insights into cuticle composition, development and function, very few have focused on the adult leaves of cereal crops, whose cuticle has a significant impact on the agricultural performance of these key crops. This project will discover genes that control cuticle development and function in corn, evaluate the potential for improvement of the leaf cuticle to help produce crops with increased drought tolerance and resistance to diseases, and generate tools to guide these efforts.Prior studies have laid a foundation for understanding cuticle biogenesis and function in plants, but very few have focused on adult leaves of economically important cereal crops such as maize, and none have yet been translated to crop improvements. This project will analyze the biogenesis of adult maize leaf cuticle and its genetic basis, and will elucidate the impact of genetically determined cuticle variation on drought tolerance and pathogen penetration. The first aim is to relate genome-wide analysis of epidermal gene expression to changes in cuticle structure, composition, and function across a developmental timecourse. The second aim is to identify loci controlling cuticular evaporation (CE) rate in adult leaves via a genome-wide association study (GWAS). The third aim is to analyze maize lines selected for diversity in cuticle function to elucidate relationships between cuticle characteristics (histology, ultrastructure and composition), cuticle function as a barrier against water loss and pathogen penetration, and drought tolerance. The fourth aim is to elucidate, via network analysis, the relationships between gene expression, cuticle composition, and cuticle function. This final aim is expected to identify key genetic regulators and a systems-level understanding of the genetic basis for cuticle biogenesis and function in adult maize leaves. Project outcomes will include new insights regarding adult maize leaf cuticle development and its genetic regulation, new knowledge of the impact of cuticle modification on drought tolerance and pathogen infection in maize, and genetic tools to guide such modifications. Project outcomes and data will be communicated through multiple open access publications, a project website housed at http://labs.biology.ucsd.edu/smith/, and deposition of data to three long-term repositories: the NCBI Short Read Archive (http://www.ncbi.nlm.nih.gov/sra), Maize GDB (http://www.maizegdb.org/), and an interactive database to be hosted by the UCSD library (http://library.ucsd.edu/dc). Participation in this project will provide interdisciplinary training opportunities preparing young scientists at various stages of their education to enter the science workforce of the future. It will also broaden participation in science by involving approximately 120 undergraduates at all institutions combined, with a focus on students with minimal prior access to research opportunities and/or awareness of science career opportunities.