Reduced Salinity Interacts with Enriched Nitrogen to Enhance the Photosynthetic Efficiency of Chlorophyta Ulva fasciata  

作　　者：WAN Mingyue BAI Lingling NI Guangyan LI Li TAN Yehui LI Gang 

机构地区：[1]Key Laboratory of Tropical Marine Bio-Resources and Ecology,South China Sea Institute of Oceanology,Chinese Academy of Sciences,Guangzhou 510530,China [2]Daya Bay Marine Biology Research Station,Chinese Academy of Sciences,Shenzhen 518121,China [3]University of Chinese Academy of Sciences,Beijing 100049,China [4]School of Pharmaceutical Science,Southern Medical University,Guangzhou 510515,China [5]Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems,South China National Botanical Garden,Chinese Academy of Sciences,Guangzhou 510650,China

出　　处：《Journal of Ocean University of China》2025年第1期130-138,共9页中国海洋大学学报(英文版)

基　　金：funded by the National Key Research and Development Program of China(No.20022YFC3102405);the National Natural Science Foundation of China(Nos.42425004,32371665);the Natural Science Foundation of Guangdong Province(Nos.2022A1515011461,2022A1515011831)。

摘　　要：Macroalgae dominate nutrient dynamics and function as high-value foods for microbial,meio-and macrofaunal communities in coastal ecosystems.Because of this vital role,it is important to clarify the physiological information associated with environmental changes as it reflects their growth potential.To evaluate the effects of the changes in salinity and nutrients,the photosynthetic efficiency of a green macroalga Ulva fasciata from the Daya Bay was tested at a range of salinity(i.e.,31 to 10 psu)and nitrogen content(i.e.,5 to 60μmol L^(-1)).The results showed that cellular chlorophyll a(Chl a),carbohydrate and protein contents of U.fasciata were increased due to reduced salinity,and were decreased by interactive nitrogen enrichment.Within a short culture period(i.e.,18 h),the reduced salinity decreased the maximum photosynthetic efficiency(rETRmax and Pmax)derived from the rapid light response curve and photosynthetic oxygen evolution rate versus irradiance curve,respectively,as well as the saturation irradiance(E_(K)).This reducing effect diminished with enlonged cultivation time and reversed to a stimulating effect after 24 h of cultivation.The nitrogen enrichment stimulated the rETRmax and Pmax,as well as the E_(K),regardless of salinity,especially within short-term cultivation period(i.e.,<24 h).In addition,our results indicate that seawater freshening lowers the photosynthetic efficiency of U.fasciata in the short term,which is mitigated by nitrogen enrichment,but stimulates it in the long term,providing insight into how macroalgae thrive in coastal or estuarine waters where salinity and nutrients normally covary strongly.

关 键 词：reduced salinity nitrogen enrichment photosynthetic efficiency Ulva fasciata Daya Bay 

分 类 号：P73[天文地球—海洋科学]