Departamento de Agronomia, Universidade Estadual de Maringá, Maringá, Paraná, Brasil.
Laboratório de Melhoramento Genético Vegetal, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Campos dos Goytacazes, Rio de Janeiro, Brasil.
PLoS One. 2018 Jun 28;13(6):e0199539. doi: 10.1371/journal.pone.0199539. eCollection 2018.
Gray leaf spot is a maize foliar disease with worldwide distribution and can drastically reduce the production in susceptible genotypes. Published works indicate that resistance to gray leaf spot is a complex trait controlled by multiple genes, with additive effect and influenced by environment. The aim of this study was to identify genomic regions, including putative genes, associated with resistance to gray leaf spot under natural conditions of disease occurrence. A genome wide association study was conducted with 355,972 single nucleotide polymorphism markers on a phenotypic data composed by 157 tropical maize inbred lines, evaluated at Maringá -Brazil. Seven single nucleotide polymorphisms were significantly associated with gray leaf spot, some of which were localized to previously reported quantitative trait loci regions. Three gene models linked to the associated single nucleotide polymorphism were expressed at flowering time and tissue related with gray leaf spot infection, explaining a considerable proportion of the phenotypic variance, ranging from 0.34 to 0.38. The gene model GRMZM2G073465 (bin 10.07) encodes a cysteine protease3 protein, gene model GRMZM2G007188 (bin 1.02) expresses a rybosylation factor-like protein and the gene model GRMZM2G476902 (bin 4.08) encodes an armadillo repeat protein. These three proteins are related with plant defense pathway. Once these genes are validated in next studies, they will be useful for marker-assisted selection and can help improve the understanding of maize resistance to gray leaf spot.
灰斑病是一种世界性分布的玉米叶部病害，可严重降低感病基因型的产量。已发表的研究表明，对灰斑病的抗性是一种由多个基因控制的复杂性状，具有累加效应，并受环境影响。本研究旨在鉴定与自然发病条件下灰斑病抗性相关的基因组区域，包括潜在的基因。在巴西马兰加进行了一项全基因组关联研究，使用了 355972 个单核苷酸多态性标记，对由 157 个热带玉米自交系组成的表型数据进行了评估。有 7 个单核苷酸多态性与灰斑病显著相关，其中一些位于先前报道的数量性状位点区域。与相关单核苷酸多态性相关的 3 个基因模型在开花期和与灰斑病感染相关的组织中表达，解释了相当大比例的表型方差，范围从 0.34 到 0.38。基因模型 GRMZM2G073465（bin 10.07）编码半胱氨酸蛋白酶 3 蛋白，基因模型 GRMZM2G007188（bin 1.02）表达核糖体蛋白样蛋白，基因模型 GRMZM2G476902（bin 4.08）编码一个盔甲蛋白重复蛋白。这三种蛋白质都与植物防御途径有关。一旦这些基因在下一阶段的研究中得到验证，它们将有助于标记辅助选择，并有助于提高对玉米灰斑病抗性的理解。
