Faculty Member

Profile

Research Interest

To understand the molecular mechanisms by which plants defend themselves against wide array of insect herbivores, and to use this knowledge in developing insect control strategies. We use forward and reverse genetics approach, biochemical techniques, metabolomics and imaging to expedite novel discoveries in plant defense against insect herbivory.

Key interests: Plant-Insect interactions, Chemical Ecology, Calcium Channels and Chemical Defense, Jasmonic Acid signaling, Metabolomics, Spodoptera, Piriformospora indica

Research Area

1) Mechanisms underlying rapid plant perception of insect attack: More than 1 million herbivorous insect species are known, and many lead to crop loss worldwide. Plants have evolved sophisticated defense mechanism to counteract insect attack very rapidly using calcium signals. The early events in plant perception of insect attack is largely unexplored and we have uncovered a major role for the calcium channel, Cyclic Nucleotide Gated Channels (CNGC19) in plant defense against herbivory (Meena et al., 2019, Plant Cell). We identified a key functional role for CNGC19 in plant defense against S. litura, via Ca2+-mediated defense signaling that modulates phytohormones (jasmonates) and secondary metabolites (glucosinolates). We are further characterizing the role of additional CNGCs in herbivory induced plant immunity. Majority of plant defense upon lepidopteran insect feeding is co-ordinated by jasmonic acid (JA/JA-Ile) dependent signaling cascade. We also study the role of JA-Ile as a possible damage signal and novel players involved in its biosynthesis and perception in plants, using R-Geco based imaging and Aequorin based forward genetic screen. We further use metabolomics to identify the plant response to herbivory and how alterations in early signaling genes impact secondary metabolite production.  We have identified novel metabolites involved in the interaction of Spodoptera with its host plants Tomato (Kundu et al., 2018, Planta) and Maize.

 Key to plant survival against voraciously feeding insects is quick local and systemic communication between cells. Plants possess a rapid systemic stress signaling system in the absence of a central nervous system, as in animals. We identified for the first time that upon insect herbivory, plants send systemic calcium signals to unwounded leaf (Kiep et al., 2015, New Phytologist). Changes in electrical signal, membrane potential, and Ca2+ result in systemic signaling upon herbivory. Molecular components involved in production local and systemic signals, the factor that moves from leaf to leaf and decoding mechanisms are our further areas of interest.

 Mechanisms of plant-microbial symbiont recognition:

Mutualistic relationships between the plant roots and the microbes that inhabit the rhizosphere are crucial factor in plant survival as they aid in improving plant growth and overcome stress. The endophytic fungi, Piriformospora indica colonizes the roots of many plant species including Arabidopsis and promotes their growth, development and seed production. The fungus stimulates nutrient uptake and confers resistance to various biotic and abiotic stresses. Using plant growth promoting fungus, Piriformopsora indica and its host, Arabidopsis thaliana we intend to understand the molecular mechanisms by which symbiotic fungi in roots provide growth advantage to whole plants (Jogawat et al., 2020, JExB, Kundu et al., Plant Physiology, 2022) and utilize the knowledge to develop novel strategies to improve crop yields.