Nutrient availability regulates Deschampsia antarctica photosynthetic and stress tolerance performance in Antarctica

GAGO J; NADAL M; CLEMENTE-MORENO MJ; FIGUEROA CM; MEDEIROS DB; CUBO-RIBAS N; CAVIERES, LOHENGRIN; GULÍAS J; FERNIE AR; FLEXAS J; BRAVO LA

JOURNAL OF EXPERIMENTAL BOTANY

OXFORD UNIV PRESS

Lugar: Oxford; Año: 2023 vol. 74 p. 2620 - 2637

0022-0957

Deschampsia antarcticais one of the only two native vascular plants in Antarctica, mostly locatedin the ice-free areas of the Peninsula’s coast and adjacent islands. Thisregion is characterized by a short growing season, frequent extreme climaticevents, and soils with reduced nutrient availability. However, it is unknownwhether its photosynthetic and stress tolerance mechanisms are affected by theavailability of nutrients to deal with this particular environment. We studiedthe photosynthetic, primary metabolic, and stress tolerance performance of D. antarctica plants growing on threeclose sites (<500 m) with contrasting soil nutrient conditions. Plants fromall sites showed similar photosynthetic rates, but mesophyll conductance andphotobiochemistry were more limiting (~25%) in plants growing on low-nutrientavailability soils. Additionally, these plants showed higher stress levels andlarger investments in photoprotection and carbon pools, most probably driven bythe need to stabilize proteins and membranes, and remodel cell walls. Incontrast, when nutrients were readily available, plants shifted their carboninvestment towards amino acids related to osmoprotection, growth, antioxidants,and polyamines, leading to vigorous plants without appreciable levels ofstress. Taken together, these findings demonstrate that D. antarctica displays differential physiological performances tocope with adverse conditions depending on resource availability, allowing it tomaximize stress tolerance without jeopardizing photosynthetic capacity.