Faculty of Jilin Provincial Key Laboratory of Plant Spectral Regions Science and Green Production, Jilin Normal University, Siping 136000, China.
Faculty of Biological Science and Technology, Baotou Teachers' College, Baotou 014030, China.
Funct Plant Biol. 2021 Oct;48(11):1175-1185. doi: 10.1071/FP20386.
Excessive UVB reaching the earth is a cause for concern. To decipher the mechanism concerning UVB resistance of plants, we studied the effects of UVB radiation on photosynthesis and metabolic profiling of Rhododendron chrysanthum Pall. by applying 2.3Wm-2 of UVB radiation for 2days. Results showed that maximum quantum yield of PSII (Fv/Fm) and effective quantum yield of PSII (φPSII) decreased by 7.95% and 8.36%, respectively, following UVB exposure. Twenty five known metabolites were identified as most important by two different methods, including univariate and multivariate statistical analyses. Treatment of R. chrysanthum with UVB increased the abundance of flavonoids, organic acids, and amino acids by 62%, 22%, and 5%, respectively. UVB irradiation also induced about 1.18-fold increase in 11 top-ranked metabolites identified: five organic acids (d-2,3-dihydroxypropanoic acid, maleic acid, glyceric acid, fumaric acid and suberic acid), four amino acids (l-norleucine, 3-oxoalanine, l-serine and glycine), and two fatty acids (pelargonic acid and myristoleic acid). In addition, UVB irradiation increased the intermediate products of arginine biosynthesis and the TCA cycle. Taken together, the accumulation of flavonoids, organic acids, amino acids and fatty acids, accompanied by enhancement of TCA cycle and arginine biosynthesis, may protect R. chrysanthum plants against UVB deleterious effects.
过量到达地球的 UVB 是一个值得关注的问题。为了解析植物对 UVB 抵抗的机制，我们通过应用 2.3Wm-2 的 UVB 辐射处理 2 天，研究了 UVB 辐射对映山红光合作用和代谢轮廓的影响。结果表明，UVB 暴露后 PSII 的最大光化学量子产量（Fv/Fm）和有效量子产量（φPSII）分别降低了 7.95%和 8.36%。通过两种不同的方法，包括单变量和多变量统计分析，确定了 25 种已知代谢物为最重要的代谢物。用 UVB 处理映山红增加了类黄酮、有机酸和氨基酸的丰度，分别增加了 62%、22%和 5%。UVB 照射还诱导了 11 种排名最高的代谢物的含量增加了约 1.18 倍：五种有机酸（d-2,3-二羟基丙酸、马来酸、甘油酸、富马酸和琥珀酸）、四种氨基酸（l-正亮氨酸、3-酮丙氨酸、l-丝氨酸和甘氨酸）和两种脂肪酸（葵酸和豆蔻酸）。此外，UVB 照射增加了精氨酸生物合成和 TCA 循环的中间产物。总之，类黄酮、有机酸、氨基酸和脂肪酸的积累，伴随着 TCA 循环和精氨酸生物合成的增强，可能保护映山红植物免受 UVB 的有害影响。
