营养盐对泰来草光合无机碳利用方式的影响  

Effects of nutrients on the utilization pattern of photosynthetic inorganic carbon of the tropical Thalassia hemprichii

作　　者：林基桢 江志坚[1,2,3,4,5,6] 李玲兰 方扬 吴云超 刘松林[1,2,3,5,6] 黄小平 Jizhen Lin;Zhijian Jiang;Linglan Li;Yang Fang;Yunchao Wu;Songlin Liu;Xiaoping Huang(Key Laboratory of Tropical Marine Bio-resources and Ecology,South China Sea Institute of Oceanology,Chinese Academy of Sciences,Guangzhou 510301,China;Innovation Academy of South China Sea Ecology and Environmental Engineering,Chinese Academy of Sciences,Guangzhou 510301,China;Southern Marine Science and Engineering Guangdong Laboratory,Guangzhou 511458,China;University of Chinese Academy of Sciences,Beijing 100049,China;Key Laboratory of Tropical Marine Biotechnology of Hainan Province,Sanya Institute of Ocean Eco-Environmental Engineering,South China Sea Institute of Oceanology,Chinese Academy of Sciences,Sanya 572100,China;Guangdong Provincial Key Laboratory of Marine Biology Applications,Guangzhou 510301,China)

机构地区：[1]中国科学院南海海洋研究所,热带海洋生物资源与生态重点实验室,广州510301 [2]中国科学院南海生态环境工程创新研究院,广州510301 [3]南方海洋科学与工程广东省实验室(广州),广州511458 [4]中国科学院大学,北京100049 [5]三亚海洋生态环境工程研究院,海南省热带海洋生物技术重点实验室,三亚572100 [6]广东省应用海洋生物学重点实验室,广州510301

出　　处：《科学通报》2023年第6期684-694,共11页Chinese Science Bulletin

基　　金：国家自然科学基金(41976144,U1901221,41730529,42176158);海南省科技专项(ZDYF2021SHFZ254);中国科学院南海生态环境工程创新研究院自主部署项目(ISEE2021PY06,ISEE2021ZD03);广东省应用海洋生物学重点实验室运行经费(2020B1212060058)资助。

摘　　要：海草光合无机碳利用策略的研究有助于揭示其生态适应机理.然而,目前有关营养盐对海草光合无机碳利用策略的影响方式尚不清楚,亟待开展研究.本研究选取两个受不同程度人类活动影响且环境营养盐差异较大的热带典型海草床(海南岛潭门和西沙永兴岛海域),结合氧电极技术、叶绿素荧光技术和非损伤微测技术,对比探讨海草优势种泰来草(Thalassia hemprichii)光合无机碳利用方式的异同.研究发现,在添加碳酸酐酶抑制剂乙酰唑胺(acetazolamide,AZ)和乙氧苯噻唑胺(6-ethoxyzolamide,EZ)后,潭门海域泰来草光合放氧速率显著降低,但AZ和EZ的抑制差异不大,表明其主要通过胞外碳酸酐酶的作用吸收HCO_(3)^(-);同时添加碱性缓冲液三氨基甲烷盐酸盐(hydroxymethyl,Tris),对潭门泰来草光合放氧的抑制率高达100%,且最大相对电子传递速率和H^(+)内流速率降低,表明其存在H^(+)/HCO_(3)^(-)协同转运方式.然而,在添加AZ和EZ后,西沙永兴岛泰来草光合放氧速率和最大电子传递速率没有显著变化,且Tris缓冲液对其光合放氧的抑制超过100%,并显著降低最大电子传递速率,这表明西沙永兴岛泰来草主要以H^(+)/HCO_(3)^(-)协同转运为主.因此,处于受人类活动影响较大、营养负荷较高且可利用光较弱的海南岛海域泰来草,既可通过胞外碳酸酐酶催化HCO_(3)^(-)转化为CO_(2)后进入细胞,也可通过H^(+)/HCO_(3)^(-)协同转运进入细胞;而处于受人类活动影响较少、营养负荷较低且可利用光较强的西沙海域泰来草,则主要依靠H^(+)/HCO_(3)^(-)协同转运进入细胞.当泰来草面临比较不利的高营养盐与弱光生长环境,需要增加光合无机碳利用策略(如胞外碳酸酐酶的作用),以提高对无机碳的利用能力来满足抗逆和生长的需求,这表明泰来草具有根据地域环境选择性表达无机碳利用方式的能力.Studies on the utilization strategy of photosynthetic inorganic carbon of seagrass can reveal its ecological adaptation mechanism.Thalassia hemprichii,a widely distributed seagrass species in the Indo-Pacific and Atlantic coastal seas,needs to evolve several utilization patterns of inorganic carbon to adapt different environments and meet its growth,development and reproduction.However,the effect of nutrient on the photosynthetic inorganic carbon utilization strategy in seagrass is still unknown and further research is urgently needed.Therefore,using oxygen electrode technology,chlorophyll fluorescence technology,and non-invasive micro-test technology,this study examined the similarity and difference in the utilization patterns of photosynthetic inorganic carbon of T.hemprichii from two typical tropical seagrass beds(Tanmen,Hainan Island,and Yongxing Island,Xisha),that were affected by varying degrees of human activity.Experiments showed that the photosynthetic oxygen release rate,maximum relative electron transfer rate,and half-saturated light intensity of T.hemprichii in Yongxing Island waters were 24.95%,24.54%,and 28.73%higher than the corresponding in Tanmen,Hainan Island.This indicated that the growth status of T.hemprichii in the waters of Yongxing Island was better with higher photosynthetic efficiency.The addition of acetazolamide(AZ)and ethoxyzolamide(EZ)significantly reduced the photosynthetic oxygen release rate of T.hemprichii,with an insignificant difference in the inhibition between AZ and EZ.This indicated that it mainly absorbed HCO_(3)^(-)via extracellular carbonic anhydrase catalysis.Meanwhile,hydroxymethyl(Tris)inhibited the photosynthetic oxygen release of T.hemprichii in Tanmen by up to 100% and decreased the maximum relative electron transfer rate and the H^(+)inward flow rate,implying a synergistic H^(+)/HCO_(3)^(-)transport mode.On the other hand,the rate of photosynthetic oxygen release and the maximum electron transfer rate of T.hemprichii in Xisha did not change significantly with the

关 键 词：海草 营养盐 无机碳利用 叶绿素荧光技术 氧电极技术 非损伤微测技术 

分 类 号：Q945.11[生物学—植物学]