Two for the price of one: Tomato TPK09 sensitizes plants to both pathogen attack and light stress

Title : Two for the price of one: Tomato TPK09 sensitizes plants to both pathogen attack and light stress

Abstract:

Plant responses to pathogens often rely on receptor-like cytoplasmic kinases (RLCKs) that mediate signaling through interactions with receptor kinases and downstream components. Here, we studied the functions of the tomato RLCK, TPK1b Related Protein Kinase (TPK09) in pathogen and light mediated pathogen responses. Tomato tpk09 mutants generated through CRISPR-Cas9 gene editing were susceptible to B. cinerea with increasing disease severity under light-emitting diode (LED) when compared to Fluorescence light (FL) and F. oxysporum. Mutant plants showed severe necrosis and elevated H2O2 accumulation under LED lighting conditions in the absence of pathogen inoculation. Further, TPK09 mitigates damage to the photosynthetic system under elevated light stress, demonstrated by a decrease in the effective photochemical quantum yield of PSII and electron transport rate in the mutant plants. In addition, TPK09 expression is induced by light but suppressed under dark conditions, and the mutant seedlings were insensitive to hypocotyl growth responses to light. RNA-seq studies suggest TPK09 is required for expression of genes involved in light harvesting, photosynthesis, and stress response functions. In summary, TPK09 plays a key role in enhancing fungal resistance, maintaining the homeostasis of the photosynthetic apparatus and ROS levels, and mitigating photooxidative damage.

Biography:

Sara Gebremeskel Hailemariam is a molecular plant pathologist whose research focuses on plant immune signaling, gene editing, and the development of resilient crops under biotic and abiotic stress. She earned her Ph.D. in Botany and Plant Pathology from Purdue University, where she characterized receptor-like cytoplasmic kinases (RLCKs) in tomato and uncovered their roles in defence signaling and light-mediated plant–pathogen interactions. She is currently a Postdoctoral Scientist at Corteva Agriscience in Johnston, Iowa, where she works on resistance gene discovery in a major crop. Her research combines molecular biology, functional genomics, and multi-omics approaches. She is passionate about global food security and sustainable agriculture and actively engages in professional development and outreach, including youth policy boards and agricultural innovation forums.