Computational identification, characterization, and expression analysis of MLO genes in two powdery mildew resistant and susceptible lines of sunflower

Abstract

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.