Lee Hyun-Min, Park Jee-Soo, Kim So-Jeong, Kim Seung-Gyu, Park Young-Doo
Department of Horticultural Biotechnology, Kyung Hee University, 1732 Deogyoung-daero, Giheung-gu, Yongin-si 17104, Gyeonggi-do, Korea.
Genes (Basel). 2022 Mar 18;13(3):542. doi: 10.3390/genes13030542.
Gray mold disease caused by in onions ( L.) during growth and storage negatively affects their yield and quality. Exploring the genes related to gray mold resistance in onion and their application to the breeding of resistant onion lines will support effective and ecological control methods of the disease. Here, the genetic relationship of 54 onion lines based on random amplified polymorphic DNA (RAPD) and in vitro-cultured onion lines infected with gray mold were used for screening resistance and susceptibility traits. Two genetically related onion lines were selected, one with a resistant and one with a susceptible phenotype. In vitro gray mold infection was repeated with these two lines, and leaf samples were collected for gene expression studies in time series. Transcript sequences obtained by RNA sequencing were subjected to DEG analysis, variant analysis, and KEGG mapping. Among the KEGG pathways, 'α-linoleic acid metabolism' was selected because the comparison of the time series expression pattern of (), (), and transcription factor () genes between the resistant and susceptible lines revealed its significant relationship with gray-mold-resistant phenotypes. Expression pattern and SNP of the selected genes were verified by quantitative real-time PCR and high-resolution melting (HRM) analysis, respectively. The results of this study will be useful for the development of molecular marker and finally breeding of gray-mold-resistant onions.
洋葱（L.）在生长和储存期间由引起的灰霉病会对其产量和品质产生负面影响。探索洋葱中与抗灰霉病相关的基因及其在抗灰霉病洋葱品系育种中的应用，将有助于实现对该病害的有效且生态友好的防治方法。在此，基于随机扩增多态性DNA（RAPD）分析了54个洋葱品系的遗传关系，并利用体外培养的感染灰霉病的洋葱品系筛选抗性和感病性状。选择了两个具有遗传相关性的洋葱品系，一个表现为抗病，另一个表现为感病。对这两个品系重复进行体外灰霉病感染，并及时收集叶片样本用于基因表达研究。对通过RNA测序获得的转录本序列进行差异表达基因（DEG）分析、变异分析和KEGG通路映射。在KEGG通路中，选择了“α-亚麻酸代谢”通路，因为对抗病和感病品系之间（）、（）和转录因子（）基因的时间序列表达模式进行比较后发现，该通路与抗灰霉病表型存在显著关联。分别通过定量实时PCR和高分辨率熔解（HRM）分析对所选基因 的表达模式和单核苷酸多态性（SNP）进行了验证。本研究结果将有助于开发分子标记，最终用于培育抗灰霉病洋葱品种。
