Effect of SnRK1 on dynamics of proline accumulation under salt stress in Arabidopsis thaliana

BARBIERI G; PAROLA R; MARTÍNEZ NOËL G; RODRIGUEZ M

Lisboa

Workshop; EMBO workshop Target of Rapamycin in photosynthetic organisms; 2021

EMBO

Most abiotic stresses induce metabolic alterations and entail a great energy cost, restricting plant growth. Balancing energy requirements with supplies is a major challenge where the kinase SnRK1 plays a central role in response to energy homeostasis. Under stress conditions, proline accumulation is a typical response in plants, and it is due to the regulation of the genes that encode the biosynthesis (P5CS1, P5CR, OAT) and catabolism (ProDH, p5CDH) enzymes. Considering that the catabolism of proline generates energy and that SnRK1 is involved in plant energy homeostasis, we hypothesized that SnRK1 will be crucial in this process. Thus, we analyzed the spatio-temporal accumulation of proline under salt stress in Arabidopsis plants with altered expression of the catalytic subunit of SnRK1 (SnRK1.1ox, snrk1.1) and wild-type. Our results showed a delayed accumulation of proline under NaCl 100 mM in the SnRK1.1ox with respect to the wild-type in root and shoot, meanwhile, the snrk1.1 showed a slight rise in the proline content in roots with respect to control. Regarding transcriptional regulation, main differences were observed at catabolism level, where shoot of SnRK1.1ox plants subjected to salt stress for 3h up-regulate proDH1 and p5CDH genes while col-0 and snrk1.1 did not modify the proDH1 expression and had a minor increase of p5CDH. All data suggest that SnRK1 is involved in the dynamic of proline accumulation under salt stress, possibly through the increase of the catabolism at short-term stress and later in the metabolite accumulation.Financial support: INTA-2019-PD-E6-I116-001, INTA- 2019-PE-E6-I142-001