Nuclear-SnRK1 localization improves salt stress tolerance responses

LANDO A; BARBIERI G; NOME C; MARTÍNEZ NOËL G; RODRIGUEZ M

Congreso; RAFV 2023; 2023

Nuclear-SnRK1 localization improves salt stress tolerance responsesAna Paula Lando (1); Giuliano Barbieri (2;3); Claudia Nome (4); Giselle Martínez-Noël (1); Marianela Rodriguez (2;3) (1)Instituto de Investigaciones en Biodiversidad y Biotecnología (INBIOTEC-CONICET). Fundación para Investigaciones Biológicas Aplicadas (FIBA). Vieytes 3103, Mar del Plata, Argentina. (2) Unidad de Estudios Agropecuarios (UDEA), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Córdoba, Argentina. (3) Instituto de Fisiología y Recursos Genéticos (IFRGV), Centro de Investigaciones Agropecuarias (CIAP), Instituto Nacional de Tecnología Agropecuaria (INTA), Córdoba, Argentina. (4) Instituto de Patología Vegetal (IPAVE), Centro de Investigaciones Agropecuarias (CIAP), Instituto Nacional de Tecnología Agropecuaria (INTA), Córdoba, Argentina.Salinization has long been known as a common environmental problem worldwide which directly affects photosynthesis and crop yield. Because of this, adaptation of metabolism and growth to adverse environmental conditions is essential to maintain cellular homeostasis and, therefore, organism survival. In this context, we studied the SnRK1 kinase which plays a central role to maintain energy and metabolism homeostasis, as a regulator of signaling networks for stress tolerance responses in plants. The aim of this work was to evaluate the impact of subcellular localization of SnRK1α-subunit (nuclear or cytosolic) in ultrastructure cell, chloroplast function, dry biomass in plants under salt stress. We evaluated cellular ultrastructure (TEM) and chlorophyll fluorescence (ChlF) in transgenic plants with forced SnRK1α-subunit localization (NLS- nuclear localization or MYR- cytosolic localization) and Wild-Type (Col-0) subjected to NaCl treatments. Results showed that NLS plants subjected to salt stress had cells with more organelles such as mitochondria and peroxisomes in relation to MYR-plants. NLS-mitochondria showed change in the morphology of their cristae and had shape cupped. MYR-chloroplasts presented structural distortion and possessed swollen thylakoids and poorly developed stroma. This phenotype was reflected in the ChlF analysis of MYR-plants, showing heat energy dissipation (NPQ, qL), changes in thylakoid electron transport with lower proton conductivity (LEF, gH+) in the PCA. Interestingly, at the end of experiment, NLS-plants subjected to salt conditions maintained similar dry biomass to the ones without stress and showed Na/K decrease in relation to MYR-plants. Overall, the results reveal key roles for nuclear SnRK1 in response to tolerance to NaCl stress.Financial support: PICT2019-02118; PIP-1701; PICT2021-00229; INTA I116; INTA I084