Glutathione-mediated thermomorphogenesis and heat stress responses in Arabidopsis thaliana

Abstract

In the context of climate change, the global rise of temperature and intense heat waves affect plant development and productivity. Among the molecular perturbations that high temperature induces in living cells is the accumulation of reactive oxygen species (ROS), which perturbs the cellular redox state. In plants, the dynamics of the cellular and subcellular redox state has been poorly investigated under high temperature. Glutathione plays a major role in maintaining the cellular redox state. We investigated its contribution in adaptation of Arabidopsis thaliana to contrasted high temperature regimes, high ambient temperature inducing thermomorphogenesis and heat stress affecting plant viability. Using the genetically- encoded redox marker roGFP2, we show that high temperature regimes lead to cytoplasmic and nuclear oxidation and impact the glutathione pool. This pool is restored within a few hours, which likely contributes to plant adaptation to high temperatures. Moreover, low glutathione mutants fail to adapt to heat stress and to induce thermomorphogenesis, suggesting that glutathione is involved in both heat adaptation mechanisms. We also evaluate the transcriptomic signature in the two high temperature regimes and identified gene expression deviations in low glutathione mutants, which might contribute to their sensitivity to high temperature. Thus, we define glutathione as a major actor in the adaptation of the plant to contrasting high temperature regimes.

Localization of four class I glutaredoxins in the cytosol and the secretory pathway and characterization of their biochemical diversification

“…Glutathione is well-established to play key roles in the response to a multitude of abiotic and biotic stresses (Noctor et al, 2012(Noctor et al, , 2018. Partial glutathione deficiency renders Arabidopsis seedlings highly sensitive to moderately high temperatures, which led to the definition of glutathione as a major player in thermomorphogenesis and heat stress responses in Arabidopsis (Dard et al, 2023). While high temperatures lead to oxidation of the glutathione pool in the cytosol and the nucleoplasm, single null mutants grxc1, grxc2, grxc3, and grxc4 did not show hightemperature sensitivity.…”

Localization of four class I glutaredoxins in the cytosol and the secretory pathway and characterization of their biochemical diversification

“…Glutathione is well established to play key roles in the response to a multitude of abiotic and biotic stresses (Noctor et al, 2012; Noctor et al, 2018). Partial glutathione deficiency renders Arabidopsis seedlings highly sensitive to moderately high temperatures, which led to the definition of glutathione as a major player in thermomorphogenesis and heat stress responses in Arabidopsis (Dard et al, 2023). While high temperatures lead to oxidation of the glutathione pool in the cytosol and the nucleoplasm, single null mutants grxc1 , grxc2 , grxc3 , and grxc4 did not show high-temperature sensitivity.…”

“…Glutathione is well established to play key roles in the response to a multitude of abiotic and biotic stresses (Noctor et al, 2012;Noctor et al, 2018). Partial glutathione deficiency renders Arabidopsis seedlings highly sensitive to moderately high temperatures, which led to the definition of glutathione as a major player in thermomorphogenesis and heat stress responses in Arabidopsis (Dard et al, 2023).…”