Plants inevitably receive harmful UV-B radiation when exposed to solar energy, so they have developed a variety of strategies to protect against UV-B radiation damage during long-term evolution. In this study, Zebrina pendula Schnizl. was used to investigate the plant defence against UV-B radiation because of its strong adaptability to sunlight changes, and the colour of its leaves changes significantly under different sunlight intensities. The experiment was carried out to study the changes of Z. pendula leaves under three light conditions: artificial daylight (control check); shading 50%; and artificial daylight + UV-B, aiming to explore the mechanism of defence against UV-B radiation by observing changes in leaf morphological structure, anthocyanin content and distribution. Results showed that the single leaf area increased but leaves became thinner, and the anthocyanin content in the epidermal cells decreased under 50% shading. In contrast, under daylight + UV-B, the single leaf area decreased but thickness increased (mainly due to the increase of the thickness of the upper epidermis and the palisade tissue), the trichomes increased. In addition, the anthocyanin content in the epidermal cells and phenylalanine ammonia-lyase (PAL) activity increased, and the leaf colour became redder, also, the photosynthetic pigment content in mesophyll cells and the biomass per unit volume increased significantly under daylight + UV-B. Thus, when UV-B radiation was enhanced, Z. pendula leaves reduced the exposure to UV-B radiation by reducing the area, and reflect some UV-B radiation by growing trichomes. The UV-B transmittance was effectively reduced by increasing the single leaf thickness and anthocyanin content to block or absorb partial UV-B. Through the above comprehensive defence strategies, Z. pendula effectively avoided the damage of UV-B radiation to mesophyll tissue.

植物在暴露于太阳能时不可避免地会受到有害的 UV-B 辐射，因此它们制定了多种策略来防止长期进化过程中受到 UV-B 辐射的伤害。在这项研究中，Zebrina pendula  Schnizl。用于研究植物对UV-B辐射的防御能力，因为它对阳光变化的适应性很强，并且在不同的阳光强度下其叶子的颜色会发生显着变化。进行实验以研究摆锤的变化三种光照条件下的叶子：人造日光（对照检查）；遮光 50%；和人工日光+UV-B，旨在通过观察叶片形态结构、花青素含量和分布的变化来探索抵御UV-B辐射的机制。结果表明，在50%遮光下，单叶面积增加但叶片变薄，表皮细胞中花青素含量下降。相比之下，在日光+UV-B下，单叶面积减少但厚度增加（主要是由于上表皮和栅栏组织的厚度增加），毛状体增加。此外，表皮细胞中的花青素含量和苯丙氨酸解氨酶（PAL）活性增加，叶色变红，日光+UV-B下叶肉细胞光合色素含量和单位体积生物量显着增加。因此，当 UV-B 辐射增强时，Z. pendula叶子通过减少面积来减少对 UV-B 辐射的暴露，并通过生长毛状体来反射一些 UV-B 辐射。通过增加单叶厚度和花青素含量来阻挡或吸收部分UV-B，有效降低UV-B透射率。通过上述综合防御策略，Z. pendula有效避免了UV-B辐射对叶肉组织的损伤。