Proteomic analysis reveals molecular mechanism of Cd tolerance in the leaves of halophyte Halogeton glomeratus.

Halogeton glomeratus (H. glomeratus) is categorized as a halophyte, it can potentially endure not only salt but also heavy metals. The aim of this work was to study the molecular mechanisms underlying the Cd tolerance of halophyte H. glomeratus seedlings. For that we used a combination of physiological characteristics and data-independent acquisition-based proteomic approaches. The results revealed that the significant changes of physiological characteristics of H. glomeratus occurred under approximately 0.4 mM Cd condition and that Cd accumulated in Cd-treated seedling roots, stems and leaves. At the early stage of Cd stress, numerous differentially abundant proteins related to "phosphoenolpyruvate carboxylase", "transmembrane transporters", and "vacuolar protein sorting-associated protein" took important roles in the response of H. glomeratus to Cd stress. At the later stage of Cd stress, some differentially abundant proteins involved in "alcohol-forming fatty acyl-CoA reductase", "glutathione transferase", and "abscisic acid receptor" were considered to regulate the adaptation of H. glomeratus exposed to Cd stress. Finally, we found various detoxification-related differentially abundant proteins related to Cd stress. These biological processes and regulators synergistically regulated the Cd tolerance of H. glomeratus. SIGNIFICANCE: The halophyte, H.glomeratus, has a strong tolerance to salinity, also survives in the heavy metal stress. At present, there are few reports on the comprehensive characterization and identification of Cd response and adaption related regulators in H.glomeratus. This research focuses on the molecular mechanisms of H. glomeratus tolerance to Cd stress at proteome levels to uncover the novel insight of the Cd-related biological processes and potential candidates involved in the response and adaption mechanism. The results will help elucidate the genetic basis of this species' tolerance to Cd stress and develop application prospect of wild genetic resources to heavy metal phytoremediation.