NaCl胁迫对荒漠苔藓齿肋赤藓膜结构稳定性的影响  

Membrane stability of the desert moss Syntrichia caninervis Mitt.during NaCl stress

作　　者：林晓华 卓一林 柳丽芳 施翔 卓露 LIN Xiaohua;ZHUO Yilin;LIU Lifang;SHI Xiang;ZHUO Lu(Xinjiang Production and Construction Corps Key Laboratory of Oasis Town and Mountain-basin System Ecology,Ministry of Education Key Laboratory of Xinjiang Phytomedicine Resource Utilization,School of Life Sciences,Shihezi University,Shihezi 832000,China)

机构地区：[1]石河子大学生命科学学院新疆植物药资源利用教育部重点实验室绿洲城镇与山盆系统生态兵团重点实验室,石河子832000

出　　处：《生态学报》2024年第8期3483-3491,共9页Acta Ecologica Sinica

基　　金：新疆兵团人才发展专项(CZ00150102);国家自然科学基金项目(32360097)。

摘　　要：苔藓结皮作为生物土壤结皮演替的最高阶段和生物量的最主要贡献者,对维持荒漠地表稳定和改善微环境具有重要作用。齿肋赤藓Syntrichia caninervis Mitt.作为荒漠苔藓结皮的优势种,是不可多得的开展抗逆性资源研究的重要材料。研究对齿肋赤藓进行不同NaCl浓度(0、200、300和400 mmol/L)和不同胁迫时间(处理1 d、2 d、3 d、5 d、7 d和14 d)处理,主要从结构特性和生理特性对其膜结构进行研究。结果表明:齿肋赤藓在中浓度NaCl胁迫(200 mmol/L和300 mmol/L)下均未观察到电导率显著变化,而随着胁迫时间的增加,细胞超微结构发生明显变化,特别在高浓度NaCl胁迫(400 mmol/L)下,细胞发生严重的质壁分离,叶肉细胞部分发生死亡,且出现大量泡状结构,而叶绿体大部分解体,片层结构消失,淀粉粒数量增加且体积变大,但这一过程中没有膜损坏的直接证据。据此关于齿肋赤藓耐受NaCl胁迫的膜结构稳定性有2种可能推测:(1)齿肋赤藓具有特殊的形态和解剖特征,例如:细胞壁较厚,且存在角隅加厚现象,使其能够在恶劣的盐胁迫环境下生存,并保留细胞结构完好无损;(2)在NaCl胁迫过程中,快速且持续的增加可溶性糖(“组成性”保护物质)和游离脯氨酸,有助于提高细胞膜的稳定性。荒漠苔藓齿肋赤藓虽然没有被定义为盐生植物,但以上研究结果表明,齿肋赤藓可以作为一种新的模式物种展开关于盐胁迫方面的研究。The moss Syntrichia caninervis Mitt.is one of the dominant species in the biological soil crusts of desert.It has long been the focus of scientific research owing to the ecological value of S.caninervis has special significance for researching on its salt resistance.We investigated the changes in membrane structures of S.caninervis,and biochemical and physiological parameters under varying salt concentration gradients of NaCl(0,200,300,and 400 mmol/L)for 1,2,3,5,7 and 14 days in this study.The results showed that it tolerated 200 mmol/L NaCl quite well.Electron micrographs of the fine structure of the cells were obtained,and no significant changes in electrical conductivity were observed at low salt concentrations.However,major changes in cell ultrastructure were observed at 300 and 400 mmol/L.Additionally,osmoregulatory substances and chlorophyll content reduced with increasing salt concentration and treatment time.In conclusion,S.caninervis has special morphological characteristics(e.g.the cell wall),which can enable it to survive in harsh salt stress environments and preserve the cell structure,while remaining intact after the release of NaCl stress;(2)During NaCl stress,a rapid and sustained increase in soluble sugars(“constitutive”protective substances)and free proline contributes to membrane(For example,the cell wall is thick and there is corner thickening phenomenon),enabling it to survive in harsh salt stress environments and preserve the cell structure,while remaining intact after the release of NaCl stress.Although it is not ecologically classified as a halophyte,our results suggest that it could be a novel plant model species to explore various aspects of salt stress.

关 键 词：盐胁迫 沙漠植物 齿肋赤藓 生理指标 透射电镜 

分 类 号：Q948[生物学—植物学]