Role of brassinosteroids in salt tolerance responses of halophytic woody plants: a study on Strombocarpa strombulifera (Lam.) A. Gray plants.

LLANES, ANALÍA; GATICA, MARIELA; LOPEZ, ELOY; MASCIARELLI, OSCAR; IPARRAGUIRRE, JULIA

Congreso; XXXIV Argentinian Meeting of Plant Physiology RAFV Conference 2023; 2023

SAFV

Brassinosteroids (BR) are a type of hormones that regulate growth and stress responses of plants. However, how BR levels modify the salt tolerance resistance of halophytic woody plants requires further investigation. In this study, the role of BR in growth responses of Strombocarpa strombulifera plants under salinity was analyzed. Plants were grown in hydroponic solutions and exposed to NaCl, Na2SO4, or their iso-osmotic mixture at different osmotic potentials (-1.0, -1.9, and -2.6 MPa). To clarify the role of BR and its relation with abscisic acid (ABA), the control (without salt) and salt-treated plants were sprayed with ABA. Different parameters were measured in all plants, including shoot height, root length, root biomass, shoot biomass, transpiration rate, hydric content, and ABA and BR endogenous levels. Root and leaves of salt-treated plants showed a high production of 24-epibrassinolide and castasterone (BR compounds), which increased in the plants sprayed with ABA. Na2SO4-treated plants showed reduced growth, and elevated levels of ABA and BR. In iso-osmotic mixture-treated plants intermediate values were observed in the levels of these phytohormones as compared to NaCl or Na2SO4 treatment. This study indicates that BR would contribute to sodium salts tolerance responses of halophytic woody S. strombulifera plants. These findings contribute to the understanding of how BR biosynthesis regulation is involved in the responses to different sodium salts in soils, which could be used as new tools for forest breeding.