Heat stress triggers protein secretion into the extracellular matrix of sorghum cell suspension cultures

ABSTRACT: Plants reprogram gene expression as an adaptive response to survive high temperatures. While the identity and functions of intracellular heat stress-responsive proteins have been extensively studied, the heat response of proteins secreted to the extracellular matrix is unknown. Here, we used Sorghum bicolor, a species adapted for growth in hot climates, to investigate the extracellular heat-induced responses. When exposed to 40 C for 72 h, heat-sensitive Arabidopsis cell suspension cultures died, while ICSB338 sorghum cell cultures survived by activation of a transcriptional response characterized by the induction of HSP70 and HSP90 genes. Quantitative proteomic analysis of proteins recovered from cell culture medium revealed specific heat stress-induced protein expression within the sorghum secretome. Of the 265 secreted proteins identified, 100 responded to heat, with the majority (85%) possessing a predicted signal peptide for targeting to the classical secretory pathway. The differentially expressed proteins have putative functions in detoxification (36%), metabolism (32%) and protein modifications (19%), while 13% are unclassified. Extracellular proteins play a vital role in cell-cell communications during stress adaptation. Our study reveals new insights into the adaptive response of sorghum to heat and provides a useful resource of extracellular proteins that could serve as targets for developing thermotolerant crops.

INSTRUMENT(S): TripleTOF 6600

ORGANISM(S): Sorghum Bicolor

TISSUE(S): Plant Cell, Cell Culture

SUBMITTER: Adrian Brown  

LAB HEAD: Stephen Chivasa

PROVIDER: PXD021536 | Pride | 2020-10-29

REPOSITORIES: Pride