鱼腥藻响应温度胁迫的形态及生理策略
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摘要:
为了探究温度对鱼腥藻形态和生理的影响,研究了鱼腥藻FACHB-82在10、25、35和40℃不同温度条件下的生长和光合特性、群体形态的变化及其响应机制.研究表明:随着温度的升高,鱼腥藻的光合活性和生长速率增加.与对照组25℃相比,低温(10℃)条件下鱼腥藻群体尺寸变小,藻丝变长,单个藻细胞变宽,具有更小的藻丝和细胞比表面积;而高温(35、40℃)条件下鱼腥藻形态变化趋势相反.对多糖含量分析发现,鱼腥藻在低温条件下胞内多糖含量减少,胶被多糖含量显著增加,表明鱼腥藻倾向于积累胶被多糖以抵抗低温胁迫;而在高温条件下,鱼腥藻累积胞内多糖,溶解态多糖与胶被多糖比值较高,胶被结构松散,表明鱼腥藻形态调节更多的是依赖胶被物质而不是胞外溶解性多糖.由此可见,鱼腥藻FACHB-82的胶被结构在温度胁迫中发挥了重要作用,且在高温条件下鱼腥藻以快速生长的方式使群体尺寸变大,胶被结构变得松散进而可能影响热传导以适应高温环境.
The frequent occurrence of cyanobacteria blooms worldwide is one of the most obvious threats to the freshwater ecosystems.Especially in the context of global climate change,it will further increase the dominance of cyanobacteria in aquatic systems.To understand how temperature regulates the morphology and physiology of Anabaena,a clonial Anabaena sp.FACHB-82 was selected and used to compare their responses to varied temperature regime(10,25,35 and 40℃),in terms of growth,photosynthetic characteristics,morphological changes and content of polysaccharide.It showed that the photosynthetic activity and growth rate of Anabaena sp.FACHB-82 were significantly enhanced by the increased temperature.Compared with the control group at 25℃,the Anabaena sp.FACHB-82 at the low temperature(10℃)exhibited smaller colonial size,longer filament,wider single cells,as well as smaller specific surface area.However,the Anabaena sp.FACHB-82 at the high temperature(35 and 40℃)demonstrated the opposite trends.The result of polysaccharide showed that the intracellular polysaccharide content of Anabaena sp.FACHB-82 decreased and the external layer’s polysaccharide increased significantly at low temperature,indicating that Anabaena sp.FACHB-82 tends to accumulate external layer to resist low temperature stress.A rapid increase in intracellular polysaccharide and the ratio of dissolved polysaccharides to external layer with the external layer becoming looser were clearly observed at high temperature,and the morphological regulation of Anabaena sp.FACHB-82 depended more on external layer than extracellular dissolved polysaccharide.These findings suggest that the external layer of Anabaena sp.FACHB-82 plays an important role in temperature adaptation,whereas under high temperature conditions,Anabaena sp.FACHB-82 increases the colonial size by accelerating growth,and the presence of loosly external layer influenced heat transfer to adapt to the high temperature.
作者:
肖湘玥 韩雯睿 于晓涵 肖艳
Xiao Xiangyue;Han Wenrui;Yu Xiaohan;Xiao Yan(University of Chinese Academy of Sciences,Beijing 100049,China;Chongqing Institute of Green and Intelligent Technology,Chinese Academy of Sciences,Chongqing 400714,China)
机构地区:
中国科学院大学
出处:
《河南师范大学学报(自然科学版)》 CAS 2024年第1期135-143,共9页
Journal of Henan Normal University(Natural Science Edition)
基金:
国家自然科学基金(51979262)。
关键词:
温度 鱼腥藻 胶被 群体 多糖
temperature Ananbena external layer colony polysaccharide
分类号:
X173 [环境科学与工程—环境科学]
