Interplay Between TTL3 and BIK1 Control Cellulose Biosynthesis under Salt Stress
Vítor Amorim-Silva (Spain)1; Francisco Percio (Spain)1; Raquel Pagano-Márquez (Spain)1; Ángel Del-Espino (Spain)1; Ryan Toth (Switzerland)2; Jessica Pérez-Sancho (Spain)1; Alberto P. Macho (China)3; Thomas A. DeFalco (Switzerland)2 4; Staffan Persson (Denmark)5; Cyril Zipfel (Switzerland)2; Miguel A. Botella (Spain)1;
1 - Área de Mejora y Fisiología de Plantas, Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora”, Universidad de Málaga‐Consejo Superior de Investigaciones Científicas (IHSM La Mayora UMA‐CSIC), Universidad de Málaga, Málaga, Spain.; 2 - Institute of Plant and Microbial Biology and Zürich-Basel Plant Science Center, University of Zürich, Zürich, Switzerland.; 3 - Shanghai Center for Plant Stress Biology, Shanghai Institutes of Biological Sciences, Chinese Academy of Sciences, Shanghai, China.; 4 - Present address: Department of Biology, Western University, London, Ontario, Canada.; 5 - Copenhagen Plant Science Center (CPSC), Department of Plant & Environmental Sciences, University of Copenhagen, Copenhagen, Denmark.;
Keywords: Cellulose synthase complex regulation; TTL3 phosphorylation; Salt stress;
Abstract Topics: Theme 9: Cell Wall Function and Signaling in plant adaptation to Biotic and Abiotic Stresses
Type of Presentation: Poster
Abstract text: Land plants account for nearly 80% of Earth’s biomass, with cellulose representing approximately one-third of this total. Adaptive remodeling of the primary cell wall is essential for growth under adverse conditions, yet the molecular pathways linking abiotic stress perception to cellulose synthase complex (CSC) regulation are largely unknown.
We previously identified TETRATRICOPEPTIDE THIOREDOXIN-LIKE (TTL) proteins as components of the CSC, displaying a dynamic association with the CSC under salt stress. Moreover, TTL proteins are required to sustain cellulose synthesis under high salinity, linking salt stress perception to CSC regulation at the plasma membrane.
Here we report that TTL3 association with the plasma membrane localized CSC is dependent on the phosphorylation of Serine 93 that is localized in the N-terminus Intrinsic Disordered Region of TTL3. We have further identified the receptor-like cytoplasmic kinase BOTRYTIS-INDUCED KINASE1 (BIK1) as the kinase responsible for this phosphorylation and therefore we show that BIK1 is a central regulator of TTL3 localization and function. Although BIK1 has been primarily characterized in plant immunity, our results uncover a role in modulating cell wall biosynthesis under salt stress.