Transcriptomic analyses of xylem specific tissues form Fusarium infected chickpea roots

Fusarium wilt is the most destructive soil-borne disease that poses a major threat to chickpea production. Plant resistance towards Fusarium wilt is a very complex phenomenon. In a compatible interaction, the main interface between the host and fungus is the root xylem vessels. The resistant plants known for early pathogen perception triggered molecular reprogramming leading to the activation of downstream defense responses for pathogen restriction. To comprehensively understand the interaction between Fusarium oxysporum and chickpea, the xylem-specific transcriptome analysis of wilt-susceptible (JG62) and wilt-resistant (WR315) genotypes at an early time point was investigated. Differential expression analysis showed that 1,368 and 348 DEGs responded to pathogen infection in resistant and susceptible genotypes, respectively. Transcriptional reprogramming in response to Foc2 was detected in both genotypes but the responses were more drastic in WR315 as compared to JG62. KEGG pathway analysis revealed that metabolic pathways, biosynthesis of secondary metabolites, phenylpropanoid biosynthesis, plant hormone signal transduction and carbon metabolism were enriched in both the genotypes under Fusarium wilt. Genes associated with defense-related metabolites synthesis such as thaumatin-like protein 1b, cysteine-rich receptor-like protein kinases, MLP-like proteins, polygalacturonase inhibitor 2-like, ethylene-responsive transcription factors, glycine-rich cell wall structural protein-like, beta-galactosidase like, subtilisin-like protease, thioredoxin-like protein, chitin elicitor receptor kinase-like, proline transporter-like, non-specific lipid transfer protein and sugar transporter were mostly up-regulated in resistant as compared to susceptible genotypes. This study's result may contribute to identifying disease resistance genes, which would help in understanding the Foc resistance mechanism in chickpea