Transcriptomic analyses of LtEpg1-and VvKINβ1-transgenic plants in response to Lasiodiplodia theobromae infection

Abstract

Botryosphaeria dieback, caused by the notorious pathogenic agent Lasiodiplodia theobromae, severely threatened the yield and quality of grapes globally. A comprehensive understanding of the fungal pathogenesis and plant defence will be of great importance to the development of efficient control measures. In previous publication, a secreted endopolygalacturonase LtEpg1 from L. theobromae was reported to interact with a SNF1-related protein kinase (SnRK) complex regulatory subunit VvKINβ1 from grapevine. Here, we ectopically expressed LtEpg1 and VvKINβ1 genes in Nicotiana benthamiana and profiled the transcriptome of LtEpg1-and VvKINβ1-transgenic lines. It was found that, after infection by L. theobromae, a total of 6676 and 4979 differentially expressed genes (DEGs) were identified in LtEpg1-and VvKINβ1-transgenic N. benthamiana, respectively, in comparison with wild type. The DEGs were involved in a wide range of physiological processes and immune responses, including photosynthesis, carotenoid biosynthesis, glycolysis, plant pathogen interaction, mitogen-activated protein kinase (MAPK) cascades, phytohormone signal transduction, and phenylpropanoid biosynthesis. Moreover, a total of 4990, 1212 and 4227 DEGs were identified in wild type, LtEpg1-and VvKINβ1-transgenic lines infected by L. theobromae, respectively, in comparison with the corresponding line grew under normal condition without inoculation. The DEGs were significantly enriched in photosynthesis and plant hormone signal transduction, suggesting relevant pathways were interrupted during infection. These results provide novel insights for exploring the molecular mechanisms of L. theobromae-grapevine interaction and supply valuable information for the genetic improvement of resistant grapevine in-depth.