Poplar PdPTP1 Gene Negatively Regulates Salt Tolerance by Affecting Ion and ROS Homeostasis in Populus

Abstract

High concentrations of Na+ in saline soil impair plant growth and agricultural production. Protein tyrosine phosphorylation is crucial in many cellular regulatory mechanisms. However, regulatory mechanisms of plant protein tyrosine phosphatases (PTPs) in controlling responses to abiotic stress remain limited. We report here the identification of a Tyrosine (Tyr)-specific phosphatase, PdPTP1, from NE19 (Populus nigra × (P. deltoides × P. nigra). Transcript levels of PdPTP1 were upregulated significantly by NaCl treatment and oxidative stress. PdPTP1 was found both in the nucleus and cytoplasm. Under NaCl treatment, transgenic plants overexpressing PdPTP1 (OxPdPTP1) accumulated more Na+ and less K+. In addition, OxPdPTP1 poplars accumulated more H2O2 and O2·−, which is consistent with the downregulation of enzymatic ROS-scavengers activity. Furthermore, PdPTP1 interacted with PdMAPK3/6 in vivo and in vitro. In conclusion, our findings demonstrate that PdPTP1 functions as a negative regulator of salt tolerance via a mechanism of affecting Na+/K+ and ROS homeostasis.

Physiological metabolic topology analysis of Halomonas elongata DSM 2581T in response to sodium chloride stress

“…On the one hand, the proportion of carbon source utilized for CO 2 formation was lower in the comparisons between NaClL and NaClM, and on the other hand, upregulation of PPP suppled R5P and NADPH, leading to an increase in biomass. Multiple reports had implicated that salt stress led to the accumulation of high levels of ROS (Y. Lu et al, 2020; Rasouli et al, 2020), which would cause serious damage to cells. As for NADPH, it plays a vital role in both reductive biosynthesis and in the protection of cells from ROS, so that upregulation of PPP under 8% NaCl stress can improve biomass and protect cells against oxidative damage.…”

“…Multiple reports had implicated that salt stress led to the accumulation of high levels of ROS (Y. Lu et al, 2020;Rasouli et al, 2020), which would cause serious damage to cells. As for NADPH, it plays a vital role in both reductive biosynthesis and in the protection of cells from ROS, so that upregulation of PPP under 8% NaCl stress can improve biomass and protect cells against oxidative damage.…”

S-Nitrosation of Arabidopsis thaliana Protein Tyrosine Phosphatase 1 Prevents Its Irreversible Oxidation by Hydrogen Peroxide

“…This process was linked to increased levels of ROS and perturbations in Na + and K + ion homeostasis. PdPTP1 was also shown to interact with PdMPK3 and PdMPK6 in vitro and in vivo (Lu et al, 2020). Thus, it appears that the PTP1 protein has an important role in the response to salt stress in plants.…”

Quercus suber Roots Activate Antioxidant and Membrane Protective Processes in Response to High Salinity

“…The cellular and molecular mechanisms involved in adaptation to salinity is starting to be unveiled in model tree species, such as Populus and crops [6][7][8][9]. Several studies support an increase of transcripts associated to antioxidant enzymes in response to abiotic stress [3], namely CSD1 and MSD1 (coding for cytosolic and mitochondrial superoxide dismutase), and CAT2 and APX2 coding, respectively, for catalase and ascorbate peroxidase proteins, however, the stress response remains unclear in cork oak.…”