Signaling

Melatonin (N-acetyl-5-methoxytryptamine) is a highly conserved molecule and at least 20 plant families are known where it plays a universal role in various physiological functions. Melatonin in plants is synthesized from tryptophan, through tryptamine, serotonin and N-acetylserotonin as intermediaries. It acts as a long distance messenger due to its amphiphilic nature and can easily be transported via the xylem from roots to other plant organs. As a signalling molecule, melatonin has an impact on the plant metabolism via regulating other phytohormones. Also, melatonin influences the plant's internal clock, regulating circadian rhythms essential for physiological processes. Accumulating evidence over the past decade suggests that melatonin fortifies plants against biotic stress responses. In this project, we aim to uncover whether and how melatonin mediates the molecular dialogue between plants and parasitic nematodes.

Calcium acts as a signaling molecule, regulating the expression of defense-related genes, initiating the synthesis of antimicrobial compounds, and prompting the reinforcement of cell walls to hinder pathogen invasion. Calcium sensory proteins, including calmodulins (CaMs), Calmodulin-like proteins (CMLs) and calcium-dependent protein kinases (CDPKs), interpret these calcium signals, modulating various defense pathways. In the early stages of plant-nematode interaction, such as root invasion and the induction of feeding sites, calcium as signaling components within the plant's signal transduction system are presumed to play a crucial role in initiating an effective defense response. In our research, we aim to comprehend how plant cells perceive and process information via calcium and calcium signalling network while fighting with these parasitic enemies.

The G protein signalling pathway is one of the most highly conserved mechanisms that enables cells to sense and respond to changes in their environment. Heteromeric G proteins stand as essential signaling components in plants, playing a significant role in regulating fundamental processes including cell division, maintaining meristems, shaping root structures, facilitating nitrogen assimilation, and more. These proteins transmit signals, regulating host immunity against pathogens through complex signaling cascades. Research highlights their involvement in activating defense responses by modulating receptor-like kinase (RLK) and other downstream effectors. Recently, we found that G protein signaling is activated in plants during the early stage of nematode infection. In this research endeavor, our focus is on understanding the roles and contributions of diverse G protein components, their accompanying complexes, and downstream effectors pivotal in governing plant processes amidst parasitic interactions with nematodes.