Dual RNA-Seq analysis of Medicago truncatula and the pea powdery mildew Erysiphe pisi uncovers distinct host transcriptional signatures during incompatible and compatible interactions and pathogen effector candidates

Powdery mildew is a serious fungal disease of legumes. A research article published in Genomics by Dr. Chandran’s group provides novel insights into powdery mildew pathogenesis and host resistance mechanisms.  Dual RNA-Seq was used to simultaneously capture host and pathogen transcriptomes at 1 d post-inoculation of resistant and susceptible Medicago truncatula genotypes with the powdery mildew Erysiphe pisi (Ep). Differential expression analysis revealed that R-gene mediated resistance against Ep involves extensive transcriptional reprogramming. Functional enrichment of differentially expressed host genes and in silico analysis of co-regulated promoters suggests that amplification of PTI, activation of the JA/ET signaling network, and regulation of growth-defense balance correlate with resistance. In contrast, processes that favour biotrophy, including suppression of defense signaling and programmed cell death, and weaker cell wall defenses are important susceptibility factors. Lastly, Ep effector candidates and genes with known/putative virulence functions were identified, representing a valuable resource that can be leveraged to improve our understanding of legume-powdery mildew interactions.

Full article: https://www.sciencedirect.com/science/article/pii/S0888754319306123?via%3Dihub