Sunflower is one of the major oilseeds producing crops in the world. However, the crop production is affected by powdery mildew in the tropics, caused by a fungal pathogen Golovinomyces latisporus. A step towards developing genetic resistance is by identifying potential genes involved. The MLO genes when silenced provide durable and broad-spectrum resistance. In this study, we identified the MLO gene family in the genome of Sunflower using computational methods. We analyzed the chromosomal distribution, gene structure conserved motifs, and phylogenetic relationship of sunflower MLO genes with MLO genes of other species. A total of 38 MLO genes were identified which are distributed unevenly on the chromosomes with varied intron/exon gene structures. These were phylogenetically distributed into six different groups. The cis elements identified in the promoter region had hormone responsive, stress responsive, development related elements along with transcription factors. We developed recombinant inbred lines by crossing H. annuus and H. praecox (F7 generation). Further, we performed RNAseq analysis of transcriptomes sequenced from powdery mildew infected leaf samples of PMR-16 (resistant) and PMS-27 (susceptible) varieties of the recombinant inbred lines. Expression analysis revealed 12 differentially expressed genes between both varieties. Our results can be used as a reference for future functional studies.

向日葵是世界上主要的油料作物之一。然而，热带地区的作物生产受到白粉病的影响，白粉病是由真菌病原体阔孢菌引起的。发展遗传抗性的一个步骤是识别潜在的相关基因。MLO 基因沉默后可提供持久且广谱的抗性。在这项研究中，我们使用计算方法鉴定了向日葵基因组中的 MLO 基因家族。我们分析了向日葵 MLO 基因的染色体分布、基因结构保守基序以及与其他物种 MLO 基因的系统发育关系。共鉴定出38个MLO基因，它们在染色体上分布不均匀，具有不同的内含子/外显子基因结构。这些在系统发育上分为六个不同的组。在启动子区域鉴定的顺式元件具有激素响应、应激响应、发育相关元件以及转录因子。我们通过杂交H. annuus和H. praecox （F7 代）开发了重组自交系。此外，我们对重组自交系的 PMR-16（抗性）和 PMS-27（易感）品种的白粉病感染叶子样品进行了转录组测序分析。表达分析显示两个品种之间有 12 个差异表达基因。我们的结果可以作为未来功能研究的参考。