Altitudinal Variation of Metabolites, Mineral Elements and Antioxidant Activities of Rhodiola crenulata (Hook.f. & Thomson) H.Ohba

Abstract

Rhodiolacrenulata (Hook.f. & Thomson) H.Ohba is an alpine medicinal plant that can survive in extreme high altitude environments. However, its changes to extreme high altitude are not yet clear. In this study, the response of Rhodiola crenulata to differences in altitude gradients was investigated through chemical, ICP-MS and metabolomic methods. A targeted study of Rhodiola crenulata growing at three vertical altitudes revealed that the contents of seven elements Ca, Sr, B, Mn, Ni, Cu, and Cd, the phenolic components, the ascorbic acid, the ascorbic acid/dehydroascorbate ratio, and the antioxidant capacity were positively correlated with altitude, while the opposite was true for total ascorbic acid content. Furthermore, 1165 metabolites were identified: flavonoids (200), gallic acids (30), phenylpropanoids (237), amino acids (100), free fatty acids and glycerides (56), nucleotides (60), as well as other metabolites (482). The differential metabolite and biomarker analyses suggested that, with an increasing altitude: (1) the shikimic acid-phenylalanine-phenylpropanoids-flavonoids pathway was enhanced, with phenylpropanoids upregulating biomarkers much more than flavonoids; phenylpropanes and phenylmethanes upregulated, and phenylethanes downregulated; the upregulation of quercetin was especially significant in flavonoids; upregulation of condensed tannins and downregulation of hydrolyzed tannins; upregulation of shikimic acids and amino acids including phenylalanine. (2) significant upregulation of free fatty acids and downregulation of glycerides; and (3) upregulation of adenosine phosphates. Our findings provide new insights on the responses of Rhodiola crenulata to extreme high altitude adversity.

Urban Flora Riches: Unraveling Metabolic Variation Along Altitudinal Gradients in Two Spontaneous Plant Species

“…In our case, total polyphenols and flavonoid concentrations slightly increased with altitude, consistent with observations made by other researchers [ 47 , 50 ]. The samples from the 792 m site differed from the trend, potentially due to variations in pedological composition, elevated humidity during the collection period, or other ecological factors.…”

“…Another study pointed out low concentrations of tannins at high altitudes [ 53 , 54 ]. The accumulation of condensed tannins with altitude was reported in other studies [ 50 , 55 ]. Analyzing separately low-molecular-weight polyphenols (LMP) and high-molecular-weight polyphenols—tannins (HMP), other authors [ 56 ] showed that the concentration of HMP was positively correlated with altitude, unlike LMP accumulation, which was independent of altitude in the species as Pteridium caudatum (L.) Maxon and Pteridium arachnoideum (Kaulf.)…”