Understanding the interactions between plant biotic and abiotic stress through characterization of microRNA effectors in jute (Corchorus spp.)

Abstract

Jute (Corchorus spp.) is an important fibre crop in India. This smallholder’s crop is vulnerable to most devastating pathogen, Macrophomina phaseolina. It causes damping off, root rot and col- lar rot collectively known as stem rot, which results in up to 30% yield loss and low fibre quality. The pathogen first causes root rot upon drought stress and then colonizes physiologically altered stem causing stem rot at maturity, under favorable weather. However, the molecular mechanisms underlying are unknown. Plant–pathogen–weather interface is regulated by a number of genes. Existing, probe-dependent gene regulation analysis meth- SYMPOSIUM 14: PLANT GENETIC ENGINEERING ods require plant and pathogen cells to be physically separated. However, probe-independent RNA sequencing method allows plant and pathogen transcripts to be analyzed simultaneously. MicroRNA effectors serve the conserved gene regulatory mech- anisms which have been reported to control plant–pathogen interactions. Most works on miRNAs have focused only on ini- tial pathogen infection processes under controlled environment. However, miRNA-mediated regulation of disease development throughout life cycle of plants under the influence of abiotic stresses, such as drought has not been studied so far. Since, stem rot becomes severe at maturity under hot and humid weather, despite the colonization of roots by M. phaseolina at early growth stages of jute, under high soil temperature and low soil moisture (drought) conditions, the jute–M. phaseolina interaction system could provide a good model to study whether physiological alterations induced by pathogen colonization or drought stress facilitate the development of disease. Sequencing of miRNAs dur- ing this could elucidate molecular interactions between plant biotic and abiotic stress.