Functional and in silico analyses of NRP-mediated cell death pathway components in stress and senescence

• Ano de defesa: 2022
• Autor(a) principal: Fraga Netto, Otto Teixeira
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: eng
• Instituição de defesa: Universidade Federal de Viçosa; Bioquímica Aplicada
• Palavras-chave em Português: Morte celular; Células-Envelhecimento; Stress (Fisiologia); Glycine max; Biologia Molecular
• Link de acesso: https://locus.ufv.br//handle/123456789/29808; https://doi.org/10.47328/ufvbbt.2022.238

Plants are continually exposed to environmental conditions, and complex cell signaling pathways are assembled to deal with unfavorable conditions. The persistence of these environmental stress conditions often activates cell death pathways. The NRP-mediated cell death pathway, first described in soybean, has been implicated as an essential cell signaling in plants induced by multiple stress conditions. The cell death signal is transduced via the GmNRPs/GmNAC81-GmNAC30/VPE signaling module. Here, we provide evidence that the NRP-mediated cell death represents a general plant response to multiple stress and senescence. In the first chapter, we review the regulatory gene networks underlying the GmNAC-SAGs, including GmNAC081 and GmNAC030-positive regulation in leaf senescence, and describe the regulatory circuit that integrates a stress-induced cell death program with developmental leaf senescence via the NRP-NAC-VPE signaling module. In the second chapter, we unveil the superfamily and subfamily of Gm02ERD15, an upstream member of the NRP-mediated cell death response. We provide an extensive in silico analysis of the PAM2 superfamily and the ERD15-like subfamily in Arabidopsis, soybean, and rice. The PAM2 superfamily was subdivided into seven subfamilies (A-G) based on sequence conservation, structure, and domain organization. The ERD15-like subfamily or group A contains 3 conserved domains, PAM2, PAE1, and QPR. We demonstrated the differential expression profile of ERD15-like subfamily members in response to drought, senescence, and hormone induction. The ERD15- like subfamily members exhibited functional redundancy in response to drought, osmotic, and senescence conditions, as judged by complementation assays of an aterd15 mutant. We identified the senescence induction expression profile of GmERD15-like subfamily members, and AtERD15 was described as a modulator of the dark-induced senescence. The subcellular localization of the subfamily members was elucidated; we observed nuclear relocalization of AtERD15 under ER stress, osmotic stress, and ABA treatment; OsERD15 was redistributed to the nucleus under ER stress, whereas Gm03ERD15 fractionated between the nucleus and cytoplasm under all conditions. Collectively, our data indicate that NRP-mediated cell death pathway components and the ERD15-like subfamily represent multiple stress-induced modulators of senescence and stress signaling response. Keywords: Senescence. Drought stress. ERD15. NAC.