S-nitrosation modulates auxin signaling during thermomorphogenesis in Arabidopsis.

TEBEZ, NURIA MALENA; IGLESIAS, MARÍA JOSÉ; SALVAT, SILVANA; CASALONGUÉ, CLAUDIA ANAHÍ; TERRILE, MARIA CECILIA

Mendoza

Congreso; Congreso SAIB 2022; 2022

Plasticity is the ability of plants to modulate their growth and development in response to environmental fluctuations. A mild increase in environmental temperature stimulates the growth of Arabidopsis seedlings by promoting the biosynthesis of the plant hormone auxin. Additionally, an increase in ambient temperature also induces an accumulation of HSP90 protein that enhances the stability of the auxin co-receptor TIR1, required for adequate auxin signaling activation. This work aimed to determine if nitric oxide (NO) through S-nitrosation of TIR1 is part of an additional layer of regulation involved in temperature-induced hypocotyl elongation in Arabidopsis. Twenty-nine degrees stimulated hypocotyl length; however, the treatment with the NO scavenger cPTIO inhibited temperature-induced hypocotyl elongation. Additionally, seedlings triggered an increase in NO level (measured by NO-sensitive DAF-FM DA probe) after 5 h at 29 ºC, and nia1 nia2 mutant seedlings showed impaired hypocotyl elongation at 29 ºC, suggesting that NO production through Nitrate Reductase enzyme is required for thermomorphogenesis. Finally, plants overexpressing a non-nitrosable tir1 mutant protein (tir1 C140A) failed to elongate their hypocotyl at 29 °C suggesting that NO, at least in part, through S-nitrosation of TIR1 protein participates in the modulation of auxin signaling in response to temperature changing environment