Wang Xiao-Min, Zhao Guo-Qiang, Chen Jie, Jing Fang-Zheng, Li Li, Wang Yu-Ying, Ma Ping, Wu Yu-Hang, Xu Shi-Jian, He Wen-Liang
Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, Gansu Province Key Laboratory of Gene Editing for Breeding, School of Life Sciences, Lanzhou University, Lanzhou 730000, China.
State Key Laboratory of Plateau Ecology and Agriculture, Qinghai University, Xining 810016, China.
Life (Basel). 2025 Aug 29;15(9):1375. doi: 10.3390/life15091375.
Ultraviolet B (UV-B) radiation is a key environmental factor that limits plant growth and development. High UV-B intensity is a typical environmental feature in Turpan-Hami (Tuha) Basin in Xinjiang, China. In this study, the altitude-dependent UV-B adaptation strategies of plants in Tuha Basin were analyzed. Chlorophyll (Chl) and flavonoid (Fla) play an important role in absorbing UV-B radiation, scavenging free radicals, and maintaining photosynthetic performance under UV-B stress. Principal component analysis indicated that the total chlorophyll (Chl t), Chl a, Chl b, and Fla contents and the Chl a/Chl b ratio are important indicators for evaluating plant tolerance to UV-B. Noticeably, with increased altitudes, the roles of Chl b, Chl a/Chl b, and Fla become markedly significant. The characteristics of stomata, epidermal hair, and wax layer are closely correlated with the UV-B amount that reaches leaves. Epidermal hair density and cuticle thickness in leaves decreased with increased altitudes, whereas hydrogen oxide (HO) was significantly accumulated, but superoxide anion (O) remained unchanged. High altitude significantly increased the stomatal apparatus area, density and specific leaf area. Moreover, plants without epidermal hair had a larger stomatal apparatus area compared with plants with epidermal hair. However, the presence or absence of epidermal hair had no effect on cuticle thickness, HO and O levels. The carbon (C), nitrogen (N), and hydrogen (H) contents were high in plant leaves at high altitude, but the sulfur (S) content and C/N ratio were low. Taken together, plants in Tuha Basin could cope with UV-B radiation by synergistically regulating epidermal structures and synthesis of secondary metabolites. Meanwhile, these plants could further allocate and reconstruct organic elements to optimize their resource distribution in adaptation to UV-B radiation with different altitudes.
紫外线B（UV-B）辐射是限制植物生长发育的关键环境因素。高UV-B强度是中国新疆吐鲁番-哈密（吐哈）盆地的典型环境特征。本研究分析了吐哈盆地植物随海拔高度变化的UV-B适应策略。叶绿素（Chl）和类黄酮（Fla）在吸收UV-B辐射、清除自由基以及在UV-B胁迫下维持光合性能方面发挥着重要作用。主成分分析表明，总叶绿素（Chl t）、Chl a、Chl b和Fla含量以及Chl a/Chl b比值是评估植物对UV-B耐受性的重要指标。值得注意的是，随着海拔升高，Chl b、Chl a/Chl b和Fla的作用变得尤为显著。气孔、表皮毛和蜡质层的特征与到达叶片的UV-B量密切相关。叶片表皮毛密度和角质层厚度随海拔升高而降低，而过氧化氢（HO）显著积累，但超氧阴离子（O）保持不变。高海拔显著增加了气孔器面积、密度和比叶面积。此外，无毛植物的气孔器面积比有毛植物大。然而，有无表皮毛对角质层厚度、HO和O水平没有影响。高海拔地区植物叶片中的碳（C）、氮（N）和氢（H）含量较高，但硫（S）含量和C/N比值较低。综上所述，吐哈盆地的植物可以通过协同调节表皮结构和次生代谢产物的合成来应对UV-B辐射。同时，这些植物可以进一步分配和重构有机元素，以优化其资源分配，从而适应不同海拔的UV-B辐射。
