miR156/SPL network negatively regulates aluminum stress tolerance in Medicago sativa by targeting SPL13
Gamalat Allam, Yousef Papadopoulos, Mark A. Bernards, Abdelali Hannoufa (2022) miR156/SPL network negatively regulates aluminum stress tolerance in Medicago sativa by targeting SPL13. 2022 Meeting of the Canadian Association for Plant Biotechnology, May 22-25, Quebec City, Quebec (oral presentation)
Aluminum (Al) toxicity is a serious environmental stress facing global crop production in acidic soils. Al toxicity triggers oxidative damage, contributing to extensive losses in alfalfa, necessitating development of crops tolerant to this stress. microRNA156 (miR156), is highly conserved in plants and functions by downregulating SQUAMOSA-PROMOTER BINDING PROTEIN-LIKE (SPL) transcription factors. At least sixteen SPL genes are targeted for silencing by miR156 in alfalfa. In this study, we determined the function of miR156 in regulating aluminum tolerance by investigating the phenotypic changes associated with altered expression of miR156. For this, we used three miR156 overexpression alfalfa plants to investigate miR156 function at the phenotypic level. We then conducted qPCR analysis of alfalfa roots to identify SPL genes that are regulated in response to Al stress. Phenotypic analysis revealed that alfalfa plants with increased expression of miR156 had inhibited root growth, plant height, reduced number of branches, stem width, root and shoot biomass, internode length, and relative water content under Al stress. Transcript analysis revealed that SPL13 is differentially regulated in response to Al stress. The current findings suggest that miR156 OE negatively regulates alfalfa’s response to Al by inhibiting root growth and plant height, reduced number of branches, stem width, root and shoot biomass, internode length, and relative water content under Al stress by regulating SPL13.