摘要
为探究红毛菜(Bangia fuscopurpurea)适应潮汐快速变化的机制,研究选取野生红毛菜品系CY作为实验对象,将红毛菜原叶体在5个失水梯度(WL0%、30%、60%和90%)及复水状态(先在90%失水状态下保持2h然后再复水)下保持2h,从生理和转录表达水平分析其对失水/复水处理的应答机制。结果显示:红毛菜超氧阴离子(O_(2)^(-))、过氧化氢(H_(2)O_(2))、丙二醛(MDA)、脯氨酸、可溶性糖、藻红蛋白和别藻蓝蛋白含量在失水时上升;超氧化物歧化酶(SOD)及最大光化学量子产率(Fv/Fm)在失水时下降;抗坏血酸过氧化物酶(APX)和过氧化物酶(POD)的活性在失水60%时显著升高后下降;而过氧化氢酶(CAT)无显著变化。在复水后,所有生理指标均恢复至未失水处理下的水平。此外,通过差异表达基因(DEGs)富集分析,发现核糖体蛋白和热激蛋白相关基因在失水过程中上调表达,而氨基酸合成等相关基因在复水后下调表达。综上所述:红毛菜通过调节抗氧化酶活性及合成失水耐受相关核糖体蛋白等防御功能以应答失水胁迫;在复水过程中,通过抑制核糖体蛋白质合成及增强光合作用供给能量和转运有毒代谢产物以帮助红毛菜恢复生理代谢活动。研究可以加深对潮间带海藻应答失水胁迫的认识,以及为红毛菜耐干良种选育提供数据参考。
Thalli of the economically important red alga Bangia fuscopurpurea mainly inhabit the intertidal rocks.Consequently,they experience approximately two dehydration/rehydration cycles per day.During the tidal cycle,the thalli can lose around 90%of water at low tide and rapidly recover to normal water content after rehydration,indicating that B.fuscopurpurea has the ability to adapt to the rapid water changes induced by the tidal cycle.However,litter is known about the mechanisms by which B.fuscopurpurea adapts to tidal changes.Therefore,a wild strain of B.fuscopurpurea was used to assess its response to 2h dehydration(with 5 water loss rates:0,30%,60%,90%)and 2h rehydration(pretreated with 2h dehydration at a 90%water loss rate)by examining physiological traits and the transcriptome.The present study found that the maximum photochemical quantum yield(Fv/Fm)of B.fuscopurpurea decreased significantly with the increasing dehydration level.Meanwhile,the contents of superoxide anion(O_(2)^(-))and hydrogen peroxide(H_(2)O_(2))increased significantly and peaked at 30%and 60%water loss,respectively.The content of malondialdehyde(MDA)also increased with dehydration level.After rehydration,Fv/Fm and contents of O_(2)^(-)H_(2)O_(2),and MDA returned to the levels of 0 water loss rate(WL0%)treatment group.Activities of superoxide dismutase(SOD)showed a decreasing trend with increasing desiccation.Ascorbate peroxidase(APX)and peroxidase(POD)increased significantly by dehydration,both peaking at 60%water loss,while catalase(CAT)did not change significantly.After rehydration,the activities of SOD,CAT,APX,and POD all returned to the levels of the WL 0%treatment.Dehydration significantly elevated proline and soluble sugar contents of B.fuscopurpurea.Additionally,the contents of phycoerythrin and allophycocyanin increased markedly at 60%water loss.These findings suggest that the algae’s adaptation to dehydration is facilitated by enhanced intracellular antioxidant enzyme activities and antioxidant contents,and by reducing photosynthesis to minimize cell damage.In addition,by comparing the transcriptional expression profiles of B.fuscopurpurea under different dehydration and rehydration treatmetns,we screened 3043 differential genes.Differential gene enrichment analysis revealed that genes related to ribosomal proteins and heat-excited proteins were upregulated by dehydration treatment,while genes related to amino acid synthesis,aminoacyl-tRNA synthetase(aaRS),and ribosomal biogenesis-mediated ribosomal protein-related genes were significantly down-regulated by rehydration.This study further analyzed the expression patterns of these key genes and found that algae maintain intracellular homeostasis by synthesizing dehydration-tolerant ribosomal proteins and initiating defense functions such as molecular chaperones.In response to rehydration,the inhibition of amino acid metabolism,aaRS,and ribosome biogenesis-mediated synthesis of ribosomal proteins was employed to conserve energy.In addition,efforts were made to enhance the energy supply from the light reactions of photosynthesis and the transport of toxic metabolites to assist B.fuscopurpurea in resuming metabolic activities.In summary,this study analyzed the physiological and transcriptional responses of B.fuscopurpurea to dehydration and rehydration,and identified key response genes.The results can contribute to a deeper understanding of the response of intertidal macroalgae to rapid water changes,as well as provide a data reference for the selection and breeding of B.fuscopurpurea.
作者
张亚文
林密
许凯
徐燕
纪德华
王文磊
陈昌生
谢潮添
ZHANG Ya-Wen;LIN Mi;XU Kai;XU Yan;JI De-Hua;WANG Wen-Lei;CHEN Chang-Sheng;XIE Chao-Tian(Fisheries College,Jimei University,Xiamen 361021,China;Fujian Engineering Research Center of Aquatic Breeding and Healthy Aquaculture,Xiamen 361021,China;Key Laboratory of Healthy Mariculture for the East China Sea,Ministry of Agriculture,Xiamen 361021,China)
出处
《水生生物学报》
北大核心
2025年第5期197-208,共12页
Acta Hydrobiologica Sinica
基金
福建省自然科学基金(2022J01801)
农业农村部岗位科学家(GARS-50-2021)
国家自然科学基金(42376109和U21A20265)
国家重点研发计划重点专项课题(2023YFD2400103)
福建省科技计划项目区域发展项目(2023N3002)资助。
关键词
红毛菜
失水
复水
生理响应
抗氧化系统
转录组
差异表达基因
Bangia fuscopurpurea
Dehydration
Rehydration
Physiological response
Antioxidant system
Transcriptome
Differentially expressed gene
