Transcript Dynamics at Early Stages of Molecular Interactions of MYMIV with Resistant and Susceptible Genotypes of the Leguminous Host, Vigna mungo

Abstract

Initial phases of the MYMIV- Vigna mungo interaction is crucial in determining the infection phenotype upon challenging with the virus. During incompatible interaction, the plant deploys multiple stratagems that include extensive transcriptional alterations defying the virulence factors of the pathogen. Such molecular events are not frequently addressed by genomic tools. In order to obtain a critical insight to unravel how V. mungo respond to Mungbean yellow mosaic India virus (MYMIV), we have employed the PCR based suppression subtractive hybridization technique to identify genes that exhibit altered expressions. Dynamics of 345 candidate genes are illustrated that differentially expressed either in compatible or incompatible reactions and their possible biological and cellular functions are predicted. The MYMIV-induced physiological aspects of the resistant host include reactive oxygen species generation, induction of Ca2+ mediated signaling, enhanced expression of transcripts involved in phenylpropanoid and ubiquitin-proteasomal pathways; all these together confer resistance against the invader. Elicitation of genes implicated in salicylic acid (SA) pathway suggests that immune response is under the regulation of SA signaling. A significant fraction of modulated transcripts are of unknown function indicating participation of novel candidate genes in restricting this viral pathogen. Susceptibility on the other hand, as exhibited by V. mungo Cv. T9 is perhaps due to the poor execution of these transcript modulation exhibiting remarkable repression of photosynthesis related genes resulting in chlorosis of leaves followed by penalty in crop yield. Thus, the present findings revealed an insight on the molecular warfare during host-virus interaction suggesting plausible signaling mechanisms and key biochemical pathways overriding MYMIV invasion in resistant genotype of V. mungo. In addition to inflate the existing knowledge base, the genomic resources identified in this orphan crop would be useful for integrating MYMIV-tolerance trait in susceptible cultivars of V. mungo.

High throughput transcriptome analysis of coffee reveals prehaustorial resistance in response to Hemileia vastatrix infection

“…The results suggest that this gene may be involved in regulating the expression of some resistance genes or defense mechanisms only in resistant genotype. Kundu et al (2015) evidenced that the expression profiling of transcription factor of this same family (bHLH) may play a complementary and/or overlapping role in enhancing expression of downstream components of the defense pathway.…”

Breeding for Enhancing Legumovirus Resistance in Mungbean: Current Understanding and Future Directions

“…They also observed major changes in the gene expression in resistant genotypes upon MYMIV infection in the jasmonic acid biosynthesis and signal transduction pathways, cell wall modifications, and metabolic pathways (Table 5). Likewise, Kundu et al [167] found 345 candidate genes that illustrate differential expression during compatible or incompatible interactions. They categorized ESTs into nine different functional categories based on their putative functions.…”

“…Since ESTs do not provide any quantitative estimation of gene expression, gene expression of selected ESTs through quantitative PCR will give more accurate information. Kundu et al [167] studied 19 genes related to R-protein such as, the suppressor of the G2 allele of skp1 (SGT1) and heat shock protein 90 (HSP 90), systemic acquired resistance (SAR) indicator gene, pathogenesis-related (PR) genes, genes related to reactive oxygen species (ROS) homeostasis (superoxide dismutase (SOD), ascorbate peroxidase (APOX), thioredoxin (TRX), and metallothionein (MET)), signal transduction gene (such as calmodulin (CAM), and other genes like WRKY, glutathione S transferase (GST), phenylalanine ammonia lyase (PAL), ubiquitin ligase, tryptophan synthase (TS), cysteine protease (CSP), rubisco activase (RuAc), MADS box protein (MADS), auxin response factor (ARF), and oxygen-evolving complex (OEC)), at different time point intervals in both the resistant and susceptible cultivar of V. mungo against MYMIV. They also observed the coordinate action of salicylic acid-responsive pathways, Ca 2+ signaling, redox imbalance, and PR genes.…”

An Integrated Approach to Comprehend MYMIV-Susceptibility of Blackgram Cv. T9 Possessing Allele of <i>CYR1</i>, the Cognate R-Gene

“…In a previous study we have shown that in MYMIV-resistant genotype of blackgram HSP 90 was over-expressed at early hours of viral infection than in Cv. T9 [8]. This further indicates the possibility of functional inability of cyr1 in recognizing MYMIV-CP, perhaps due to folding impairment.…”

“…Likewise another set of experimental plants were forcefully fed by the starved, non-viruliferous whiteflies and referred to as mock inoculated control. Accumulation of MYMIV particles in the host plants after challenging with the virus was determined by qPCR as previously reported by Kundu et al [8].…”