GSE136268
The LRX-RALF-FER cell wall integrity sensing module controls plant growth and salt stress responses by modulating multiple plant hormones
Plants have evolved cell wall integrity signaling pathways to maintain cell wall homeostasis during rapid growth and in response to environmental stress. The cell wall leucine-rich repeat extensins LRX3/4/5, the RAPID ALKALINIZATION FACTOR (RALF) peptides RALF22/23, and FERONIA (FER) function as a module to regulate plant growth and salt stress responses via the sense of cell wall integrity. However, the intracellular signaling pathways that mediate the effects of the LRX3/4/5-RALF22/23-FER module are still largely unknown. Here, we report that jasmonic acid (JA), salicylic acid (SA), and abscisic acid (ABA) accumulate constitutively in lrx345 and fer mutants. Blocking JA pathway rescues the retarded growth phenotype of the lrx345 and fer-4 mutants, while disruption of ABA biosynthesis suppresses the salt-hypersensitivity of these mutants. Many salt stress-responsive genes display abnormal expression patterns in the lrx345 and fer-4 mutants, as well as in wild type plants treated with epigallocatechin gallate (EGCG), an inhibitor of pectin methylesterases, suggesting that the cell wall integrity is a critical factor that determines the expression of stress-responsive genes. Production of reactive oxygen species (ROS) is constitutively increased in the lrx345 and fer-4 mutants, and inhibition of ROS accumulation suppresses the salt-hypersensitivity of these mutants. Together, our results suggest that the LRX3/4/5-RALF22/23-FER module controls plant growth and salt stress responses by regulating hormonal homeostasis and ROS accumulation. Overall design: RNA-Seq of 8 samples. The samples are wild type ( WT ) and lrx345 after NaCl treatment for 0, 6, 24, and 72 h.