State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, 210023 Nanjing, China.
Institute of Food Crops, Jiangsu Academy of Agricultural Sciences, 210014 Nanjing, China.
Proc Natl Acad Sci U S A. 2019 Sep 10;116(37):18479-18487. doi: 10.1073/pnas.1910229116. Epub 2019 Aug 26.
Tetep is a rice cultivar known for broad-spectrum resistance to blast, a devastating fungal disease. The molecular basis for its broad-spectrum resistance is still poorly understood. Is it because Tetep has many more genes than other cultivars? Or does Tetep possess multiple major genes that can individually confer broad-spectrum resistance to blast? Moreover, are there many interacting pairs in the Tetep genome? We sequenced its genome, obtained a high-quality assembly, and annotated 455 nucleotide-binding site leucine-rich repeat () genes. We cloned and tested 219 genes as transgenes in 2 susceptible cultivars using 5 to 12 diversified pathogen strains; in many cases, fewer than 12 strains were successfully cultured for testing. Ninety cloned s showed resistance to 1 or more pathogen strains and each strain was recognized by multiple s. However, few s showed resistance to >6 strains, so multiple s are apparently required for Tetep's broad-spectrum resistance to blast. This was further supported by the pedigree analyses, which suggested a correlation between resistance and the number of Tetep-derived s. In developing a method to identify pairs each of which functions as a unit, we found that >20% of the s in the Tetep and 3 other rice genomes are paired. Finally, we designed an extensive set of molecular markers for rapidly introducing clustered and paired s in the Tetep genome for breeding new resistant cultivars. This study increased our understanding of the genetic basis of broad-spectrum blast resistance in rice.
特特普是一种水稻品种，以广谱抗稻瘟病而闻名，稻瘟病是一种破坏性很强的真菌病。其广谱抗性的分子基础仍知之甚少。是因为特特普比其他品种拥有更多的基因吗？还是因为特特普拥有多个能够单独赋予广谱抗稻瘟病的主要基因？此外，特特普基因组中是否存在许多相互作用的基因对？我们对其基因组进行了测序，获得了高质量的组装，并注释了 455 个核苷酸结合位点富含亮氨酸重复（）基因。我们克隆并测试了 219 个基因作为转基因，在 2 个易感品种中使用 5 到 12 种多样化的病原体菌株进行测试；在许多情况下，成功培养的菌株少于 12 种用于测试。90 个克隆的基因对 1 种或多种病原体菌株表现出抗性，每种菌株都被多个基因识别。然而，很少有基因对 >6 种菌株表现出抗性，因此特特普对稻瘟病的广谱抗性显然需要多个基因。系谱分析进一步支持了这一点，该分析表明抗性与特特普衍生基因的数量之间存在相关性。在开发一种识别每个作为一个单位发挥作用的基因对的方法时，我们发现特特普和其他 3 个水稻基因组中的基因对 >20%是成对的。最后，我们设计了一整套广泛的分子标记，用于快速引入特特普基因组中的聚类和成对基因，以培育新的抗性品种。这项研究增加了我们对水稻广谱稻瘟病抗性遗传基础的理解。
