Seri-Biotech Research Laboratory, Central Silk Board, Kodathi, Bangalore, 560035, India.
Central Silk Board, Bangalore, 560068, India.
Mol Biol Rep. 2020 Apr;47(4):2889-2900. doi: 10.1007/s11033-020-05395-6. Epub 2020 Apr 1.
Mulberry is a fast growing economically important tree for sericulture industry and contains compounds for preventing and treating several diseases and ailments. The quality and quantity of mulberry leaf available to produce silk fibre and for medicinal purpose is greatly affected by number of foliar diseases, out of which powdery mildew is the major one. Imparting genetic resistance becomes an important approach in disease management in mulberry as spraying of fungicides has harmful effects on silkworm growth and development. Deployment of non-functional susceptible genes such as Mildew resistance Locus O (MLO) against powdery mildew in few crops stimulated to identify and characterize MLO genes in mulberry. In this study, genome wide analysis identified 16 MLO genes in Morus notabilis. Phylogenetic analysis found that MnMLO2, MnMLO6A, MnMLO6B, MnMLO12A and MnMLO12B clustered with functionally characterized MLOs associated with powdery mildew susceptibility in dicot species. Gene expression analysis indicated increased transcript abundance of MnMLO2, MnMLO6A, and MnMLO12A in response to powdery mildew infection. Further, conserved motifs exclusive to functionally characterized MLOs were identified in MnMLO1C, MnMLO2 and MnMLO6A proteins. Combined analysis of the phylogenetic relationship, conserved motif analysis and gene expression in response to infection identified MnMLO2 and MnMLO6A as potential candidate genes involved in powdery mildew susceptibility in mulberry. Identification and deployment of natural and induced mutations in the candidate genes can be useful for mulberry breeding programs to develop powdery mildew resistant varieties.
桑树是一种生长迅速的经济树种，对养蚕业具有重要意义，其体内的化合物可预防和治疗多种疾病。叶片疾病会极大地影响桑树的产丝纤维质量和药用数量，其中白粉病是主要疾病。在桑树病虫害管理中，遗传抗性是一种重要方法，因为喷洒农药会对蚕的生长和发育产生有害影响。在少数作物中部署非功能易感基因（如白粉病抗性基因 O（MLO））以对抗白粉病，这刺激了在桑树中鉴定和表征 MLO 基因。在这项研究中，全基因组分析在野桑树种中鉴定出 16 个 MLO 基因。系统发育分析发现，MnMLO2、MnMLO6A、MnMLO6B、MnMLO12A 和 MnMLO12B 与在双子叶物种中与白粉病易感性相关的功能表征 MLO 聚类。基因表达分析表明，MnMLO2、MnMLO6A 和 MnMLO12A 的转录本丰度在白粉病感染后增加。此外，在 MnMLO1C、MnMLO2 和 MnMLO6A 蛋白中鉴定到仅存在于功能表征 MLO 中的保守基序。基于系统发育关系、保守基序分析和对感染的基因表达的综合分析，鉴定出 MnMLO2 和 MnMLO6A 是与桑树白粉病易感性相关的潜在候选基因。候选基因的天然和诱导突变的识别和部署可用于桑树育种计划，以开发抗白粉病品种。
