Understanding the Molecular Basis of Fusarium solani Mediated Root Rot in Pisum sativum

Primary author: Bruce Williamson-Benavides
Faculty sponsor: Amit Dhingra

Primary college/unit: Agricultural, Human and Natural Resource Sciences
Campus: Pullman

Abstract:

Pisum sativum (pea) yields have declined significantly over the last decades predominantly due to root rot caused by the fungus, Fusarium solani f. sp. pisi (Fsp). Yield losses caused by Fsp range from 15 to 60%. We hypothesize genes exhibiting differential expression and associated polymorphisms in response to Fsp challenge, will confer tolerance or susceptibility of pea to Fsp. To gain a comprehensive insight into the molecular changes that accompany Fsp infection, we performed a comparative time-course gene expression analysis of tolerant and susceptible P. sativum genotypes challenged with the Fsp pathogen. Differential gene expression and molecular pathway analyses revealed that transcription factors, pattern recognition receptors, disease-related genes, as well as genes that participate in the production of hormones and metabolites such as salicylic acid, jasmonate, ethylene, lignin, and flavonoids were differentially expressed between tolerant and susceptible genotypes. 769 differentially expressed genes with single nucleotide polymorphisms (SNPs) were identified and the putative SNPs were evaluated for being polymorphic across four tolerant and four susceptible P. sativum genotypes. The total set of SNPs with validated polymorphisms was used to screen two segregating populations generated from sets of tolerant and susceptible parents and currently a linkage-analysis is being performed. This work is expected to facilitate an understanding of the complex relationship between a host plant and its native pathogen. It is also expected to result in the identification of gene-linked molecular markers that will provide a cost-effective avenue to breed peas for resistance to root rot.