A new study led by Prof. ZHANG Daoyuan from the Xinjiang Institute of Ecology and Geography of the Chinese Academy of Sciences has uncovered the phosphorylation-mediated regulatory mechanisms of desiccation tolerance of Syntrichia caninervis, a model moss for desiccation tolerance research. Their work was published in The Plant Journal.
The researchers used four dimensional (4D) label-free high-throughput proteomics and phosphoproteomics to quantitatively analyze proteins and phosphoproteins during the dehydration-rehydration process of Syntrichia caninervis, and identified a key phosphorylated protein, ScDHAR1.
They found that the phosphorylation of ScDHAR1 at two specific serine sites (S29 and S218) significantly boosts its activity. This enhancement enables the moss to more effectively scavenge reactive oxygen species (ROS) and mitigate oxidative damage, thereby improving its desiccation tolerance.
Integrative proteomic and phosphoproteomic analyses demonstrated that phosphorylation dynamically regulates distinct metabolic pathways at different stages of dehydration and rehydration.
During dehydration, processes such as photosynthesis, glutathione metabolism, the citric acid cycle, phenylpropanoid biosynthesis, and DNA repair coordinate to maintain cellular stability and bolster protective responses.
Upon rehydration, phosphorylation activates critical recovery pathways, including ribosome biogenesis, energy metabolism, phenylalanine metabolism, and macromolecular complex assembly, ensuring the restoration of cellular functions. Glutathione metabolism emerged as a central phosphorylation-regulated pathway that mediates this complex response.
"This study significantly advances our understanding of extreme dehydration resistance and rapid rehydration capabilities of Syntrichia caninervis, and provides vital genetic insights for developing more drought-resilient crop varieties," said Prof. LI Xiaoshuang, corresponding author of the study.
