Enzyme activities suggest that the NAD-ME C4 type CCM exist in Ulva sp.
Enzyme activities suggest that the NAD-ME C4 type CCM exist in Ulva sp.
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DOI：
10.1016/j.algal.2020.101809
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发表时间：
2020-05
影响因子：
5.1
通讯作者：
Lu Zhou;Shan Gao;Li Huan;Songcui Wu;Guangce Wang;Wenhui Gu
中科院分区：
文献类型：
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作者：
Lu Zhou;Shan Gao;Li Huan;Songcui Wu;Guangce Wang;Wenhui Gu
石莼（Ulva sp.）是一种大型的潮间带绿色藻类，自2008年以来一直是青岛海域绿色潮的致潮物种。为探讨石莼大发生的生理基础，本文对石莼光合固碳机制进行了研究。测定了不同无机碳源（0、400、1500、20，000 μL·L− 1 CO2或HCO 3 −）下的生长和繁殖能力、叶绿素荧光参数、叶绿素含量以及碳酸酐酶和C4途径中其他重要酶的酶活性。当CO2浓度为0 μL·L-1CO 2时，叶绿素荧光参数[Fv/Fm，Y（II），Y（I）]和叶绿素含量显著降低，NPQ参数和MDH、PEPC酶活性显著升高，PEPCK酶活性无显著变化。当加入HCO 3 −时，叶绿素含量和NAD-ME酶活性显著降低。这些结果表明，缺乏CO2可以刺激石莼的光保护作用。包括减少叶绿素的合成和减少开放状态的PSII反应中心。可能不具有PEPCK C4型CCM，并且可能使用NAD-ME C4型CCM来耐受由缺乏CO2引起的应激。
Ulva sp. is a large intertidal species of green algae that has been a causative species in green tide in the Qingdao sea area of China since 2008. To explore the physiological basis of outbreaks, we investigated the photosynthetic carbon sequestration mechanism ofUlvasp. Growth and breeding capacity, chlorophyll fluorescence parameters, chlorophyll content, and enzyme activities of carbonic anhydrase and other important enzymes in the C4 pathway were measured when different inorganic carbon sources were provided (0, 400, 1500, 20,000 μL·L−1of CO2or HCO3−). When CO2was absent (0 μL·L−1CO2), chlorophyll fluorescence parameters [Fv/Fm, Y (II), Y(I)] and chlorophyll content decreased significantly, but NPQ parameters and MDH and PEPC enzyme activities increased significantly and PEPCK enzyme activity was not affected significantly. When HCO3−was added, chlorophyll content and NAD-ME enzyme activity decreased significantly. These results indicated that lack of CO2could stimulate photoprotection ofUlvasp. containing decreasing the synthesis of chlorophyll and reducing the PSII reaction center of the open state.Ulvasp. may not have the PEPCK C4 type CCM and might use the NAD-ME C4 type CCM to tolerate the stress caused by the lack of CO2.