Department of Bioresources Engineering, Sejong University, Seoul 05006, Korea.
ICAR-Indian Institute of Rice Research, Hyderabad 500030, India.
Int J Mol Sci. 2022 Jun 10;23(12):6524. doi: 10.3390/ijms23126524.
Pumpkin ( Duchesne ex Poir.) is a multipurpose cash crop rich in antioxidants, minerals, and vitamins; the seeds are also a good source of quality oils. However, pumpkin is susceptible to the fungus , an obligate biotrophic pathogen, which usually causes powdery mildew (PM) on both sides of the leaves and reduces photosynthesis. The fruits of infected plants are often smaller than usual and unpalatable. This study identified a novel gene that involves PM resistance in pumpkins through a genome-wide association study (GWAS). The allelic variation identified in the gene encoding for AP2-like ethylene-responsive transcription factor () was proven to be involved in PM resistance. Validation of the GWAS data revealed six single nucleotide polymorphism (SNP) variations in the coding sequence between the resistant (IT 274039 [PMR]) and the susceptible (IT 278592 [PMS]). A polymorphic marker (dCAPS) was developed based on the allelic diversity to differentiate these two haplotypes. Genetic analysis in the segregating population derived from PMS and PMR parents provided evidence for an incomplete dominant gene-mediated PM resistance. Further, the qRT-PCR assay validated the elevated expression of during PM infection in the PMR compared with PMS. These results highlighted the pivotal role of in conferring resistance to PM and identifies it as a valuable molecular entity for breeding resistant pumpkin cultivars.
南瓜（Duchesne ex Poir.）是一种多用途的经济作物，富含抗氧化剂、矿物质和维生素；其种子也是优质油的良好来源。然而，南瓜容易感染真菌，这是一种专性活体营养病原体，通常会导致叶片两面出现白粉病（PM），从而降低光合作用。受感染植物的果实通常比正常果实小且口感不佳。本研究通过全基因组关联研究（GWAS）鉴定了一个与南瓜 PM 抗性相关的新基因。基因编码的 AP2 样乙烯响应转录因子（）中鉴定出的等位基因变异被证明与 PM 抗性有关。GWAS 数据的验证揭示了抗性品种（IT 274039 [PMR]）和易感品种（IT 278592 [PMS]）之间编码区的六个单核苷酸多态性（SNP）变异。基于等位基因多样性，开发了一个多态性标记（dCAPS）来区分这两种单倍型。来自 PMS 和 PMR 亲本的分离群体的遗传分析为不完全显性基因介导的 PM 抗性提供了证据。此外，qRT-PCR 检测证实，与 PMS 相比，PMR 在 PM 感染过程中基因的表达水平升高。这些结果强调了在赋予 PM 抗性方面的关键作用，并将其鉴定为培育抗 PM 南瓜品种的有价值的分子实体。
