FERONIA-like receptor 1-mediated calcium ion homeostasis is involved in the immune response.

Calcium (Ca) is the most abundant divalent cation in plants, and cellular levels of Ca, which functions as a nutrient and secondary messenger, play a critical role in plant immunity. In the present study, we found that FERONIA-like receptor 1 (FLR1) positively regulates resistance and that expression of FLR1 is strongly induced in response to Ca deficiency. In addition, the Ca content in the shoots of was lower than that in wild-type, and the -sensitive phenotype of the mutant was not rescued by exogenous application of Ca. Moreover, RNA sequencing revealed 2,697 differentially expressed genes (DEGs) in the mutant compared with wild-type, and some of these DEGs are involved in cellular metal ion homeostasis and transition metal ion homeostasis. Changes in expression of overlapping genes between the mutant and in plants under low-Ca treatment were consistent in terms of direction, indicating that FLR1 is involved in Ca homeostasis. In summary, we detected FLR1-mediated resistance to , a phenomenon associated with Ca homeostasis.