Exocyst subunits regulate plant immune receptor FLS2.
Researchers from the IPB in together with Chinese colleagues have recently shed light on the homeostasis of the FLAGELLIN SENSING 2 (FLS2) receptor at the plasma membrane. Their results were published in New Phytologist. The plasma membrane-localized receptor kinase FLS2 recognizes bacterial flagellin and initiates microbe-associated molecular pattern-triggered immunity, which inhibits infection by bacterial pathogens. The localization, abundance, and activity of FLS2 are under dynamic control. Now, the researchers could show that Arabidopsis thaliana EXO70B1, a subunit of the exocyst complex, plays a critical role in FLS2 signaling. In both exo70B1‐3 and exo70B2‐1 mutants, the abundance of FLS2 at the plasma membrane was decreased and the flg22 response was impaired. Consistently, EXO70B1-GFP-expressing plants showed increased FLS2 accumulation at the plasma membrane and therefore enhanced FLS2 signaling. Their data revealed that EXO70B1 and its homolog EXO70B2 associate with FLS2 and with each other and mediate the trafficking of FLS2 to the plasma membrane. With these insights, the researchers could present a new layer of regulation of FLS2 function in plant immunity.
Original publication:
Wang, W., Liu, N., Gao, C., Cai, H., Romeis, T. and Tang, D. (2020), The Arabidopsis exocyst subunits EXO70B1 and EXO70B2 regulate FLS2 homeostasis at the plasma membrane. New Phytol, 227: 529-544. doi:10.1111/nph.16515