Bárány, IvettBerenguer, EduardoSolís González, María TeresaPérez Pérez, YolandaSantamaría, EstrellaCrespo, José LuisRisueño, MaríaDíaz, IsabelTestillano, Pilar2024-01-302024-01-302018Bárány I, Berenguer E, Solís MT, Pérez-Pérez Y, Santamaría ME, Crespo JL, Risueño MC, Díaz I, Testillano PS. Autophagy is activated and involved in cell death with participation of cathepsins during stress-induced microspore embryogenesis in barley. J Exp Bot. 2018 Mar 14;69(6):1387-1402. doi: 10.1093/jxb/erx455. PMID: 29309624; PMCID: PMC6019037.0022-095710.1093/JXB/ERX455https://hdl.handle.net/20.500.14352/96741This work is supported by projects AGL2014-52028-R and AGL2017-82447-R funded by the Spanish Ministry of Economy and Competitiveness (MINECO) and the European Regional Development Fund (ERDF/FEDER). YPP is the recipient of a grant (PEJ15/BIO/AI-01S8) funded by Comunidad de Madrid and European Commission through ERDF/FEDER.Microspores are reprogrammed towards embryogenesis by stress. Many microspores die after this stress, limiting the efficiency of microspore embryogenesis. Autophagy is a degradation pathway that plays critical roles in stress response and cell death. In animals, cathepsins have an integral role in autophagy by degrading autophagic material; less is known in plants. Plant cathepsins are papain-like C1A cysteine proteases involved in many physiological processes, including programmed cell death. We have analysed the involvement of autophagy in cell death, in relation to cathepsin activation, during stress-induced microspore embryogenesis in Hordeum vulgare. After stress, reactive oxygen species (ROS) and cell death increased and autophagy was activated, including HvATG5 and HvATG6 up-regulation and increase of ATG5, ATG8, and autophagosomes. Concomitantly, cathepsin L/F-, B-, and H-like activities were induced, cathepsin-like genes HvPap-1 and HvPap-6 were up-regulated, and HvPap-1, HvPap-6, and HvPap-19 proteins increased and localized in the cytoplasm, resembling autophagy structures. Inhibitors of autophagy and cysteine proteases reduced cell death and promoted embryogenesis. The findings reveal a role for autophagy in stress-induced cell death during microspore embryogenesis, and the participation of cathepsins. Similar patterns of activation, expression, and localization suggest a possible connection between cathepsins and autophagy. The results open up new possibilities to enhance microspore embryogenesis efficiency with autophagy and/or cysteine protease modulators.engAttribution 4.0 Internationaljournal article1460-2431https://doi.org/10.1093/jxb/erx45529309624open access576.32AutophagyBarleyCaspase-like activity,CathepsinsCell deathCysteine C1A proteasesMicrospore embryogenesisROSStress responseBiología celular (Biología)Biotecnología2407 Biología Celular