Research Projects

Plant-parasitic nematodes (PPNs) are major agricultural pests, causing ~12.3% yield loss globally and ~$157 billion in annual losses, including over $40 million in India. Among them, root-knot nematodes (RKNs), particularly Meloidogyne incognita, are especially destructive due to their broad host range and the severe physiological damage they inflict on crops. Conventional control methods are constrained by the lack of resistant cultivars and limited knowledge of resistance loci. A promising alternative lies in targeting effector proteins secreted by nematodes to suppress host immunity and manipulate plant cellular processes. Unravelling the function of these effectors and identifying their host interactors can reveal novel susceptibility mechanisms and guide resistance breeding. However, the obligate biotrophic nature of M. incognita makes genetic manipulation extremely challenging. Thus, host-delivered RNA interference (RNAi) provides a practical means to assess effector function indirectly via gene silencing in the host plant. Transcriptome profiling of resistant (M36) and susceptible (Pusa Ruby) tomato cultivars in the mentor’s lab identified 49 novel RKN effector candidates. Fifteen effectors, provisionally designated as Nematode Effector Proteins (NEPs), NEP1 to NEP15, were found to be strongly expressed during early stages of infection, suggesting critical roles in the parasitic process. Functional validation via dsRNA feeding to J2-stage nematodes revealed that silencing several effectors impaired infectivity, with NEP1 and NEP3 showing the strongest phenotypes. Further silencing through virus-induced gene silencing (VIGS) in tomato and stable RNAi in Arabidopsis thaliana significantly reduced infection, supporting their roles as critical parasitism factors. This project aims to investigate the molecular function of NEP1 and NEP3 through three specific objectives: 1. To generate transgenic tomato lines delivering RNAi against NEP1 and NEP3 and assess resistance against M. incognita. 2. To identify host protein interactors of NEP1 and NEP3 by overexpressing TAP-tagged versions in Arabidopsis and tomato, followed by affinity purification and subsequent mass spectrometry. 3. To compare NEP1/NEP3 interactomes in Arabidopsis and tomato to identify conserved susceptibility targets. Arabidopsis thaliana will serve as a model for interaction studies, while Solanum lycopersicum (tomato) will be used for translational validation via hairy root transformation. Comparative analysis will help identify conserved molecular nodes for engineering durable nematode resistance. This research will provide mechanistic insight into effector–host interactions and inform biotechnological strategies for managing RKNs in tomato and other crops.