水生生物学报2025，Vol.49Issue(8)：34-43,10.DOI:10.3724/1000-3207.2025.2024.0437
草鱼在不同梯度碳酸盐碱度下的生理响应
PHYSIOLOGICAL RESPONSE OF GRASS CARP(CTENOPHARYNGODON IDE-LLUS)UNDER DIFFERENT GRADIENTS OF BICARBONATE ALKALINITY
摘要
Abstract
To comprehensively assess the alkali tolerance of grass carp"Husu No.1",this study examined and analyzed the significant physiological response parameters and related gene expressions in gills of grass carp under varying NaHCO3 alkalinity gradients:low(10 mmol/L,AW-10),medium(30 mmol/L,AW-30),and high(50 mmol/L,AW-50)over a 7-day period.The findings revealed that in terms of ammonia nitrogen metabolism,as alkalinity increased,the content of blood ammonia exhibited an ascending trend,with the AW-50 group having the highest content.However,there was no significant difference(P>0.05)between the low and medium alkalinity groups and the freshwater control group.The content of serum urea nitrogen was lower than that of the freshwater control group.The activity of gluta-mate dehydrogenase(GDH)and the expressions of rhbg,rhcga,and glud1a in the gills of the medium and high alkali-nity groups were upregulated,suggesting that grass carp might carry out ammonia detoxification by enhancing the high expression of ammonia transport genes in the gills and activating the GDH pathway,thereby stabilizing the stability of blood ammonia at medium and low alkalinity.Regarding the immune response,although the numbers of three types of immune cells(white blood cells,lymphocytes,and neutrophils)in different alkalinity groups did not significantly differ from those in the freshwater control group,the numbers of these three immune cells showed an increasing trend with the increase in alkalinity,with the AW-50 group showing the greatest increase.The expression of immune-related gene c3 was significantly elevated across all alkalinity groups,while il-1β was significantly increased in the high alkalinity group,tnf-α was significantly increased in the middle alkalinity group,and more serious inflammatory reactions occurred in the middle and high alkalinity groups.In the aspect of ion and osmotic pressure regulation,there was no significant difference(P>0.05)in the contents of four serum ions(Na+,Cl-,K+and Ca2+)across the alkalinity groups compared to the freshwater control.However,the content of Na+showed a decreasing trend with the increase in alkali-nity,with the lowest content in the AW-50 group.Although the activity of sodium-potassium ATPase(NKA)in the gills in the AW-30 and AW-50 groups was significantly lower than that in the freshwater control group(P<0.05),the corresponding genes ATP1a1b and ATP1a3b were extremely significantly upregulated in the AW-30 group,suggesting that gene expression might be related to the lag in protein synthesis.In terms of blood oxygen transportation,the expressions of gill hemoglobin formation genes hbaa2 and hbba1 of grass carp under normoxia in different alkalinity groups were significantly inhibited.However,the number of red blood cells,hemoglobin content,and serum iron content increased with the increase in alkalinity,reaching the highest in the AW-50 group,indicating symptoms of hypoxia.Through comprehensive analysis,when the alkalinity is≤30 mmol/L,grass carp can basically maintain phy-siological homeostasis.However,when alkalinity exceeds this critical value,the risk of death due to ammonia poison-ing and hypoxia significantly increases.This study concludes that the alkali tolerance of grass carp is moderate,with the potential for breeding new alkali-tolerant varieties,and it is suitable for breeding and culture in water bodies with alkalinity≤30 mmol/L.关键词
碳酸盐碱度/氨氮/渗透压/血红蛋白/草鱼Key words
Bicarbonate alkalinity/Ammonia nitrogen/Osmotic pressure/Haemoglobin/Ctenopharyngodon idella分类
农业科技引用本文复制引用
邹宇婷,黄晶,鲁翠云,沈玉帮,李成浩,杨浩晨,张立民,常玉梅..草鱼在不同梯度碳酸盐碱度下的生理响应[J].水生生物学报,2025,49(8):34-43,10.基金项目
农业生物育种重大专项(2023ZD0406505) （2023ZD0406505）
中国水产科学研究院中央级公益性科研院所基本科研业务费专项(2023TD22)资助[Supported by the Biological Breeding-Major Projects(2023ZD0406505) （2023TD22）
the Central Public-interest Scientific Institution Basal Research Fund,CAFS(2023TD22)] （2023TD22）
