Inhibition of photosynthesis in the microalga Chaetoceros curvisetus(Bacillariophyta) by macroalga Gracilaria lemaneiformis(Rhodophyta)  

作　　者：叶长鹏 张梦成 杨宇峰 

机构地区：[1]Institute of Hydrobiology of Jinan University,Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institutes,Engineering Research Center for Tropical and Subtropical Aquatic Ecological Engineering,Ministry of Education

出　　处：《Chinese Journal of Oceanology and Limnology》2013年第6期1174-1180,共7页中国海洋湖沼学报（英文版）

基　　金：Supported by the National Key Technology R&D Program(No.2012BAC07B05);the National Natural Science Foundation of China(No.31000240);the Project on the Integration of Industry,Education and Research of Guangdong Province(No.2012B091100341)

摘　　要：We investigated the effects of dried macroalga Gracilaria lemaneiform （Rhodophyta） on photosynthesis of the bloom-forming microalga Chaetoceros curvisetus. C. curvisetus was cultured with different amounts of dried G. lemaneiformis under controlled laboratory conditions. We measured the photosynthetic oxygen evolution rate and established the chlorophyll a fluorescence transient （OJIP） curve coupled with its specific parameters. We observed concentration-dependent and time-dependent relationships between dried G. lemaneiformis and inhibition of photosynthesis in C. curvisetus. Co-culture with dried G. lemaneiformis also resulted in a decrease in the light-saturated maximum photosynthetic oxygen evolution rate （P^ax） in C. curvisetus, and a decrease in the OJIP curve along with its specific parameters; the maximum photochemical efficiency of PSII （FJFm）, the amount of active PSII reaction centers per excited cross section at t=0 and t=--tFM （RC/CS0 and RC/CSm, respectively）, the absorption flux per excited cross section at t=0 （ABS/ CS0）, and the efficiency with which a trapped exciton moves an electron into the electron transport chain （~u0）. The dark respiration rate （Rd） increased in C. curvisetus co-cultured with dried G. lemaneiformis. The JIP-test and the oxygen evolution results indicated that dried G. lemaneiJbrmis decreased the number of active reaction centers, blocked the electron transport chain, and damaged the oxygen-evolving complex of C. curvisetus. This result indicated that dried fragments of G. lemaneiformis could effectively inhibit photosynthesis of C. curvisetus, and thus, could serve as a functional product to control and mitigate C. curvisetus blooms.We investigated the effects of dried macroalga Gracilaria lemaneiformis(Rhodophyta)on photosynthesis of the bloom-forming microalga Chaetoceros curvisetus.C.curvisetus was cultured with different amounts of dried G.lemaneiformis under controlled laboratory conditions.We measured the photosynthetic oxygen evolution rate and established the chlorophyll a fluorescence transient(OJIP)curve coupled with its specific parameters.We observed concentration-dependent and time-dependent relationships between dried G.lemaneiformis and inhibition of photosynthesis in C.curvisetus.Co-culture with dried G.lemaneiformis also resulted in a decrease in the light-saturated maximum photosynthetic oxygen evolution rate(Pmax)in C.curvisetus,and a decrease in the OJIP curve along with its specific parameters;the maximum photochemical efficiency of PSII(Fv/Fm),the amount of active PSII reaction centers per excited cross section at t=0 and t=tFM(RC/CS0and RC/CSm,respectively),the absorption flux per excited cross section at t=0(ABS/CS0),and the efficiency with which a trapped exciton moves an electron into the electron transport chain(ψ0).The dark respiration rate(Rd)increased in C.curvisetus co-cultured with dried G.lemaneiformis.The JIP-test and the oxygen evolution results indicated that dried G.lemaneiformis decreased the number of active reaction centers,blocked the electron transport chain,and damaged the oxygen-evolving complex of C.curvisetus.This result indicated that dried fragments of G.lemaneiformis could effectively inhibit photosynthesis of C.curvisetus,and thus,could serve as a functional product to control and mitigate C.curvisetus blooms.

关 键 词：Gracilaria lemaneiformis Chaetoceros curvisetus allelopathy photosynthetic inhibition JIPtest 

分 类 号：X173[环境科学与工程—环境科学]