- Author: Kathy Keatley Garvey
Kaloshian will speak on "Root-Knot Nematode Perception and Immune Signaling in Arabidopsis" at a hybrid seminar, both in-person and virtual, at 4:10 p.m., Wednesday, June 1 in 122 Briggs Hall. The Zoom link is https://ucdavis.zoom.us/j/99515291076.
Kaloshian will discuss her recent research, "A G-lectin Receptor Kinase is a Negative Regulator of Arabidopsis Immunity Against Root-Knot Nematode Meloidogyne incognita," published in bioRxiv in October 2021. She and her colleagues found that "A plasma membrane localized G-lectin receptor kinase acts as a negative immune regulator by interfering with defense responses activated by nematode and microbial elicitors."
"Root-knot nematodes (Meloidogyne spp., RKN) are responsible for extensive crop losses worldwide," she and her colleagues wrote in their abstract. "For infection, they penetrate plant roots, migrate between plant cells, and establish feeding sites, known as giant cells, in the root pericycle. Previously, we found that nematode perception and early plant responses were similar to those for microbial pathogens and require the BAK1 co-receptor in Arabidopsis thaliana and tomato. To identify additional receptors involved in this process, we implemented a reverse genetic screen for resistance or sensitivity to RKN using Arabidopsis T-DNA alleles of genes encoding transmembrane receptor-like kinases. This screen identified a pair of allelic mutations with enhanced resistance to RKN in a gene we named ENHANCED RESISTANCE TO NEMATODES 1 (ERN1). ERN1 encodes a G-type lectin receptor kinase (G-LecRK) with a single pass transmembrane domain. Further characterization showed that ern1 mutants displayed stronger activation of MAP kinases, elevated levels of the defense marker MYB51, and enhanced H202 accumulation in roots upon RKN elicitor treatments. Elevated MYB51expression and ROS burst were also observed in leaves of ern1 mutants upon flg22 treatment. Complementation of ern1.1 with 35S- or native promotor-driven ERN1 rescued the RKN infection and enhanced defense phenotypes. Taken together, our results indicate that ERN1 is an important negative regulator of immunity."
Kaloshian, who joined the UC Riverside faculty in 1997 and chaired the Department of Nematology from 2017-2021, was named divisional dean on July 1, 2021. During her three-year term, she is overseeing four departments: Botany and Plant Sciences, Entomology, Environmental Sciences, and Nematology.
As a molecular geneticist, Kaloshian studies the interactions between plants and nematodes, and insect pests. Her grants have been funded by the National Institute of Food and Agriculture and the National Science Foundation. She has served as a senior editor of journals in her field of research. (See UC Riverside news story)
Kaloshian is a fellow of the American Association for the Advancement of Science and a recipient of the Syngenta Award for Excellence in Research from the Society of Nematologists. Her other honors include the Chancellor's Award for Excellence in Undergraduate Research and Creative Achievement, and the UC Riverside Distinguished Service Award for her development of the COVID-19 campus testing lab.
Kaloshian holds a bachelor of science degree in agricultural engineering and master's degree in plant protection from American University of Beirut. She obtained her doctorate in plant pathology from UC Riverside and completed her postdoctoral training at UC Davis.