Arabidopsis EXO70B2 exocyst subunit contributes to papillae and encasement formation in antifungal defence

0557185 - ÚEB 2023 RIV GB eng J - Journal Article
Ortmannová, Jitka - Sekereš, Juraj - Kulich, I. - Šantrůček, J. - Dobrev, Petre - Žárský, Viktor - Pečenková, Tamara
Arabidopsis EXO70B2 exocyst subunit contributes to papillae and encasement formation in antifungal defence.
Journal of Experimental Botany. Roč. 73, č. 3 (2022), s. 742-755. ISSN 0022-0957. E-ISSN 1460-2431
R&D Projects: GA MŠMT(CZ) EF16_019/0000738; GA MŠMT(CZ) LM2015062
Grant - others:OPPK(XE) CZ.2.16/3.1.00/21519
Institutional support: RVO:61389030
Keywords : nonhost resistance * callose synthase * plasma-membrane * snare-protein * complex * transport * pathogen * immune * growth * identification * Callose * exocyst * non-host resistance * penetration * secretion * snare
OECD category: Cell biology
Impact factor: 6.9, year: 2022
Method of publishing: Open access
http://doi.org/10.1093/jxb/erab457

The exocyst complex containing the EXO70B2 subunit has a specific role in papilla and encasement formation, implemented in coordination with the pathway regulated by the SYP121 SNARE complex in defence. In the reaction to non-adapted Blumeria graminis f. sp. hordei (Bgh), Arabidopsis thaliana leaf epidermal cells deposit cell wall reinforcements called papillae or seal fungal haustoria in encasements, both of which involve intensive exocytosis. A plant syntaxin, SYP121/PEN1, has been found to be of key importance for the timely formation of papillae, and the vesicle tethering complex exocyst subunit EXO70B2 has been found to contribute to their morphology. Here, we identify a specific role for the EXO70B2-containing exocyst complex in the papillae membrane domains important for callose deposition and GFP-SYP121 delivery to the focal attack sites, as well as its contribution to encasement formation. The mRuby2-EXO70B2 co-localizes with the exocyst core subunit SEC6 and GFP-SYP121 in the membrane domain of papillae, and EXO70B2 and SYP121 proteins have the capacity to directly interact. The exo70B2/syp121 double mutant produces a reduced number of papillae and haustorial encasements in response to Bgh, indicating an additive role of the exocyst in SYP121-coordinated non-host resistance. In summary, we report cooperation between the plant exocyst and a SNARE protein in penetration resistance against non-adapted fungal pathogens.
Permanent Link: http://hdl.handle.net/11104/0331251