The miR394 pathway links plant development and response to abiotic stress in Arabidopsis and maize

MISKEVISH, F; BELÉN, F; DOTTO, M; BERNARDI, Y; VEGETTI, A

Chascomús

Taller; V Taller de Biología Celular y del Desarrollo; 2022

Plants are sessile organisms which need to adjust to constantly changing environmental conditions. When plants are exposed to adverse conditions, they typically reprogram their developmental pathways in order to redirect their resources to survive under stressful conditions. Some miRNAs have been shown to have a dual role both as master regulators of key developmental processes and in the response to abiotic stress, allowing plants to quickly adjust their growth and development under stress conditions. The miR394 pathway is an interesting example that has been shown to play a role in shoot apical meristem organization and leaf development, as well as in salt and drought stress response in Arabidopsis, whereas this pathway in maize is still completely uncharacterized. We report novel aspects of miR394 regulation in Arabidopsis and maize, showing that miR394 plays a role in the control of flowering time in Arabidopsis, indirectly regulating the expression of the floral integrators FLOWERING LOCUS T (FT) and SUPPRESSOR OF OVEREXPRESSION OF CONSTANS 1 (SOC1). Interestingly, the regulation of flowering time in Arabidopsis is independent of LEAF CURLING RESPONSIVENESS (LCR), the only miR394 target reported so far. In addition, we provide evidence that this pathway in maize has a conserved role in the response to drought stress and could play a role in leaf development and in the regulation of flowering time, as reported in Arabidopsis.