Joint NSF/ERA-CAPS: Host Targets of Fungal Effectors as Keys to Durable Disease Resistance

----------------------------------------------------------------------------------------------------------------------PI：丹·内特尔顿(爱荷华州立大学)高级人事：罗杰·怀斯(USDA-ARS)，Adam Bogdanove(康奈尔大学)、Roger Innes(印第安纳大学)、Fredy Altpeter(佛罗里达大学)、Adah Lesem(爱荷华州立大学)和Jaquelyn Jackson(塔斯基吉大学)ERA-CAPS合作者：Patrick Schweizer[德国莱布尼茨植物遗传学和作物植物研究所(IPK)]和Pietro Span u(英国帝国学院)疾病造成的作物损失仍然是发达国家和发展中国家的最大农业挑战之一。专性真菌病原体，即需要寄主生存的病原体，是世界范围内农作物生产的主要威胁。这些病原体分泌的效应蛋白抑制宿主防御，促进营养物质的获取和定植。然而，这些效应器操纵这些过程的分子机制却知之甚少。该项目旨在通过鉴定大麦-白粉病、宿主-微生物系统中相互作用的寄主和病原菌蛋白网络来填补这一知识空白。之前由NSF-BBSRC联合资助的研究发现了一组由白粉菌Blumeria graminis f.sp.分泌的新型效应物。霍尔德伊，这有助于病原菌的毒力。这组效应器将用于识别宿主靶蛋白，使用酵母双杂交筛选，目的是识别多个效应器靶标的蛋白质。这些宿主靶标以及关键效应器将通过RNA干扰沉默(RNAi)和在细菌III型递送系统中过度表达来评估它们在宿主免疫中的作用。那些影响宿主免疫调节的基因将通过TAL效应核酸酶(TALEN)突变或RNAi介导的基因沉默在稳定的大麦转基因中得到进一步表征。到目前为止，已鉴定和鉴定的真菌效应物中有一种预测的金属蛋白酶(BEC1019)，它是毒力所必需的，抑制宿主防御，在进化上至少在96种不同的真菌中保守，包括经济上重要的植物病原体、动物病原体和自由生活的非病原体。作为概念的证明，大麦将采用一种新发现的系统进行工程设计，该系统将在检测到BEC1019活性时激活防御反应，预计BEC1019活性将赋予对广泛的真菌病原体的抗性。破译进化上保守的真菌效应子的分子功能，了解寄主基因的反应，将有助于阐明植物的防御机制，促进广泛适用的疾病控制策略。所有研究目标将纳入本科生和研究生、博士后和K-12教师的培训和指导机会。与欧洲ERA-CAPS(http://www.eracaps.org/)伙伴项目，“小麦属植物非寄主成分对真菌疾病持久抗性的功能表征和验证(DURESTrit)”)的国际研究交流将加强对学生和博士后的培训。将向中学、社区大学和1890个批地机构中代表性不足的群体传播“大麦性状和基因遗传”教师探究式研究体验(ITAG大麦)，提供应用于农业和人类健康的遗传学实践培训。将通过项目网站、植物和植物病原体基因表达在线数据库(www.plexd.org)以及NCBI-GEO(http://www.ncbi.nlm.nih.gov/geo/)，Ensambl Genome(http://ensemblgenomes.org/)，)和GrainGenes(ricat.pw.usda.gov))促进公众获取项目数据。因此，该项目将促进研究、教育和向广大受众传播，同时培养新一代农业和计算科学家。

----------------------------------------------------------------------------------------------------------------------PI: Dan Nettleton (Iowa State University) Senior Personnel: Roger Wise (USDA-ARS), Adam Bogdanove (Cornell University), Roger Innes (Indiana University), Fredy Altpeter (University of Florida), Adah Leshem (Iowa State University) and Jaquelyn Jackson (Tuskegee University)ERA-CAPS Collaborators: Patrick Schweizer [Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Germany] and Pietro Spanu (Imperial College, United Kingdom)Crop loss caused by disease remains one of the greatest agricultural challenges in both developed and developing countries. Obligate fungal pathogens, i.e., pathogens that require their host to survive, are a major threat to crop production worldwide. Effector proteins secreted by these pathogens suppress host defenses to promote nutrient acquisition and colonization. However, the molecular mechanisms by which these effectors manipulate these processes are poorly understood. This project aims to fill this knowledge gap by identifying the networks of interacting host and pathogen proteins in the well-characterized barley-powdery mildew, host-microbe system. Previous joint NSF-BBSRC funded research identified a collection of novel effectors secreted by the powdery mildew fungus, Blumeria graminis f. sp. hordei, that contribute to pathogen virulence. This group of effectors will be used to identify host target proteins, using yeast two-hybrid screens, with the goal of identifying proteins that are targeted by multiple effectors. These host targets, as well as key effectors, will be evaluated for their roles in host immunity by silencing via RNA interference (RNAi) and by overexpression in a bacterial type III delivery system. Those that impact host immune regulation will be further characterized using TAL effector nuclease (TALEN) mutagenesis or RNAi-mediated gene silencing in stable barley transgenics. Among the fungal effectors identified and characterized thus far is a predicted metalloprotease (BEC1019) that is required for virulence, suppresses host defenses and is evolutionarily conserved among at least 96 other diverse fungi, including economically important plant pathogens, animal pathogens, and free-living non-pathogens. As a proof of concept, barley will be engineered with a newly discovered system that will activate defense responses upon detection of BEC1019 activity, which is predicted to confer resistance to a wide range of fungal pathogens. Deciphering the molecular functions of evolutionarily conserved fungal effectors and understanding the host genes that respond will elucidate plant defense mechanisms and promote broadly applicable disease control strategies. All research objectives will be incorporated into training and mentoring opportunities for undergraduate and graduate students, postdocs, and K-12 teachers. International research exchanges with the European ERA-CAPS (http://www.eracaps.org/) companion project, "Functional characterization and validation of nonhost components in Triticeae species for durable resistance against fungal diseases (DURESTrit)", will enhance the training of students and postdocs. An inquiry-based Research Experience for Teachers on "Inheritance of Traits and Genes in Barley" (iTAG Barley) will be disseminated to serve underrepresented groups in secondary schools, community colleges, and 1890 land-grant institutions, providing hands-on training in genetics as it applies to agriculture and human health. Public access to project data will be fostered through a project website, the PLEXdb (www.plexdb.org) on-line database for gene expression for plants and plant pathogens, as well as NCBI-GEO (http://www.ncbi.nlm.nih.gov/geo/), Ensembl Genomes (http://ensemblgenomes.org/), and GrainGenes (wheat.pw.usda.gov). Thus, this project will promote research, education, and dissemination to a broad audience, while developing a new generation of agricultural and computational scientists.