| 摘要: |
| 【目的】探究长期UV-B辐射胁迫对球形棕囊藻（Phaeocystis globosa）生长、生理响应及透明胞外聚合物颗粒（transparent Exopolymeric Particles，TEP）形成的影响，明确UV-B辐射在球形棕囊藻生长过程中的作用特征。【方法】以北部湾球形棕囊藻为研究对象，设置对照组和UV-B辐射处理组（0.6 μW·cm-2，每日照射30 min），开展为期20 d的实验室培养实验。分别于第6 d、12 d和18 d取样，测定细胞密度、囊体参数、最大光合效率（Fv/Fm）、实际光能转化效率Y(Ⅱ)光合色素含量、超氧化物歧化酶（SOD）和过氧化氢酶（CAT）活性、Caspase-3-like活性及胞外多糖（Exopolysaccharides，EPS）和TEP含量等指标。【结果】UV-B辐射显著抑制球形棕囊藻的生长并损伤光合系统；SOD和CAT及Caspase-3-like活性均显著高于对照组，表明藻细胞氧化胁迫和程序性死亡增强。此外，单位藻细胞的EPS分泌能力和TEP产生量显著增加。【结论】UV-B辐射总体上不利于球形棕囊藻种群增长，但可提高单位生物量的EPS分泌和TEP释放水平，UV-B辐射可能参与球形棕囊藻受胁迫或衰亡阶段的物质转化过程。 |
| 关键词: UV-B 辐射 球形棕囊藻 生长 多糖 TEP |
| DOI： |
| 投稿时间：2026-02-04修订日期：2026-03-15 |
| 基金项目:国家自然科学(42266007)[第一,国家自然科学基金项目（面上项目，重点项目，重大项目） |
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| Effects of long-term UV-B radiation stress on the growth and TEP formation of Phaeocystis globosa |
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YANG Qiuxia1, LI Jie2, ZHOU Yanru1, WEI Wei2, LAI Junxiang2
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| (1.College of Marine and Biotechnology,Guangxi Minzu University,Nanning;2.Guangxi Academy of Sciences) |
| Abstract: |
| [Objective]This study investigated the effects of long-term UV-B radiation stress on the growth, physiological response, and formation of transparent exopolymeric particles (TEP) in Phaeocystis globosa, with the aim of clarifying the functional characteristics of UV-B radiation during the growth process of this species. [Methods] Using P. globosa isolated from the Beibu Gulf as the experimental organism, a control group and a UV-B radiation treatment group (0.6 μW·cm-2, 30 min daily irradiation) were established for a 20-day laboratory culture experiment. Samples were collected on days 6, 12, and 18 to measure cell density, colony parameters, maximum photosynthetic efficiency (Fv/Fm), actual photochemical efficiency Y(II), photosynthetic pigment content, superoxide dismutase (SOD) and catalase (CAT) activities, Caspase-3-like activity, as well as exopolysaccharides (EPS) and TEP contents. [Results] UV-B radiation significantly inhibited the growth of P. globosa and caused damage to its photosynthetic system. SOD and CAT activities, as well as Caspase-3-like activity, were all significantly higher in the treatment group than in the control, indicating that UV-B radiation intensified oxidative stress and enhanced programmed cell death in the algal cells. Furthermore, the EPS secretion capacity and TEP production per unit cell were significantly increased. [Conclusion] Overall, UV-B radiation was unfavorable for the population growth of P. globosa, but it increased the levels of EPS secretion and TEP release on a biomass-normalized basis. UV-B radiation may participate in the material transformation processes during the stress or decline stages of P. globosa. |
| Key words: UV-B radiation Phaeocystis globosa growth EPS TEP |
