Ottawa Research and Development Centre (ORDC), Agriculture and Agri-Food Canada, 960 Carling Ave, Ottawa, ON, K1A 0C6, Canada.
Morden Research and Development Centre, Agriculture and Agri-Food Canada, 101 Route 100, Morden, MB, R6M 1Y5, Canada.
BMC Genomics. 2018 Feb 9;19(1):131. doi: 10.1186/s12864-018-4513-4.
Gibberella ear rot (GER) is one of the most economically important fungal diseases of maize in the temperate zone due to moldy grain contaminated with health threatening mycotoxins. To develop resistant genotypes and control the disease, understanding the host-pathogen interaction is essential.
RNA-Seq-derived transcriptome profiles of fungal- and mock-inoculated developing kernel tissues of two maize inbred lines were used to identify differentially expressed transcripts and propose candidate genes mapping within GER resistance quantitative trait loci (QTL). A total of 1255 transcripts were significantly (P ≤ 0.05) up regulated due to fungal infection in both susceptible and resistant inbreds. A greater number of transcripts were up regulated in the former (1174) than the latter (497) and increased as the infection progressed from 1 to 2 days after inoculation. Focusing on differentially expressed genes located within QTL regions for GER resistance, we identified 81 genes involved in membrane transport, hormone regulation, cell wall modification, cell detoxification, and biosynthesis of pathogenesis related proteins and phytoalexins as candidate genes contributing to resistance. Applying droplet digital PCR, we validated the expression profiles of a subset of these candidate genes from QTL regions contributed by the resistant inbred on chromosomes 1, 2 and 9.
By screening global gene expression profiles for differentially expressed genes mapping within resistance QTL regions, we have identified candidate genes for gibberella ear rot resistance on several maize chromosomes which could potentially lead to a better understanding of Fusarium resistance mechanisms.
由于霉变谷物污染了对健康有威胁的真菌毒素，镰刀菌穗腐病（GER）是温带地区玉米最重要的经济上的真菌病害之一。为了开发抗性基因型并控制该疾病，了解宿主-病原体相互作用至关重要。
使用真菌和模拟接种的两个玉米自交系发育籽粒组织的 RNA-Seq 衍生转录组谱，鉴定差异表达的转录本，并提出在 GER 抗性数量性状位点（QTL）内定位的候选基因。由于在感病和抗病自交系中真菌感染，共有 1255 个转录本显著上调（P≤0.05）。前者（1174 个）比后者（497 个）上调的转录本更多，并且随着接种后 1 至 2 天感染的进展而增加。专注于位于 GER 抗性 QTL 区域内差异表达的基因，我们鉴定了 81 个涉及膜转运、激素调节、细胞壁修饰、细胞解毒和与致病相关蛋白和植保素生物合成的基因，这些基因被认为是抗性的候选基因。通过应用数字 PCR，我们验证了来自染色体 1、2 和 9 的抗性自交系贡献的 QTL 区域中这些候选基因的一部分的表达谱。
通过筛选位于抗性 QTL 区域内差异表达基因的全基因表达谱，我们已经鉴定出了几个玉米染色体上的 GER 抗性候选基因，这可能有助于更好地了解镰刀菌抗性机制。
