Redundant and Diversified Roles Among Selected Arabidopsis thaliana EXO70 Paralogs During Biotic Stress Responses

Frontiers in Plant Science

卷:11

Viktor Žárský¹  Martin Potocký¹  Fatima Cvrčková¹  Matěj Drs¹  Tamara Pečenková¹  Edita Janková Drdová¹  Přemysl Pejchar¹  Hana Soukupová²  Jitka Ortmannová²  Lukáš Synek²  Andrea Potocká² 

[1] Department of Experimental Plant Biology, Faculty of Science, Charles University, Prague, Czechia;

[2] Institute of Experimental Botany, CAS, Prague, Czechia;

关键词: exocyst;    EXO70;    Arabidopsis thaliana;    redundancy;    gene expression;    lipid binding;   

DOI  :  10.3389/fpls.2020.00960

来源: DOAJ

【 摘 要 】

The heterooctameric vesicle-tethering complex exocyst is important for plant development, growth, and immunity. Multiple paralogs exist for most subunits of this complex; especially the membrane-interacting subunit EXO70 underwent extensive amplification in land plants, suggesting functional specialization. Despite this specialization, most Arabidopsis exo70 mutants are viable and free of developmental defects, probably as a consequence of redundancy among isoforms. Our in silico data-mining and modeling analysis, corroborated by transcriptomic experiments, pinpointed several EXO70 paralogs to be involved in plant biotic interactions. We therefore tested corresponding single and selected double mutant combinations (for paralogs EXO70A1, B1, B2, H1, E1, and F1) in their two biologically distinct responses to Pseudomonas syringae, root hair growth stimulation and general plant susceptibility. A shift in defense responses toward either increased or decreased sensitivity was found in several double mutants compared to wild type plants or corresponding single mutants, strongly indicating both additive and compensatory effects of exo70 mutations. In addition, our experiments confirm the lipid-binding capacity of selected EXO70s, however, without the clear relatedness to predicted C-terminal lipid-binding motifs. Our analysis uncovers that there is less of functional redundancy among isoforms than we could suppose from whole sequence phylogeny and that even paralogs with overlapping expression pattern and similar membrane-binding capacity appear to have exclusive roles in plant development and biotic interactions.

【 授权许可】

Unknown