盐胁迫对朴树叶片渗透调节物质及保护酶系统的影响

Effects of salt stress on osmotic regulatory substances and protective enzyme system in Celtis sinensis

为探讨朴树的耐盐机理,为朴树在盐碱地的栽培及推广提供理论依据,研究了不同盐浓度胁迫对朴树渗透调节物质和保护酶活性的影响。选取大小基本一致的1年生朴树幼苗,正常生长3个月后分别在0‰（CK）、2‰、2.5‰、3.5‰和5‰盐浓度下进行胁迫处理,7d后测定所需生理指标,以后每10d测定1次。结果显示：0-3.5‰低盐胁迫下,渗透调节物质（可溶性糖、脯氨酸和可溶性蛋白质）含量和保护酶（SOD、POD和CAT）活性均缓慢增加;5‰盐浓度胁迫下,随着盐胁迫时间的延长,渗透调节物质（可溶性糖、脯氨酸和可溶性蛋白质）含量有所下降,SOD、POD、CAT活性随着胁迫时间的延长先升高后降低。表示：朴树可以通过渗透调节物质的增加和保护酶活性的增大来适应一定的盐胁迫环境,但高浓度、长时间的盐分胁迫对朴树的生长造成一定程度的迫害。

[Objective]Celtis sinensis were studied on different concentration salt and identified of osmotic adjustment solute and protective enzyme activity in order to lay a foundation for studying the salt-tolerant physiological mechanism of Celtis sinensis and supplied theoretical basis and practical guidance for cultivation and popularization of Celtis sinensis.[Method]Basic same size seedlings were chosen and growth for three months,then,seedlings of Celtis sinensis were managed in 0‰（CK）,2 ‰,2.5 ‰,3.5‰and 5‰salt concentration,we measured they physiological index after 7days and determination of every ten days.[Result]Under lower stress the osmotic adjustment solute content（the soluble sugar,proline,the soluble protein）and protective enzyme activities（SOD,POD,CAT）in Celtis sinensis increased slowly.Under 5‰ stress treatment,the osmotic adjustment solute content increased by the extension of salt stress time（the soluble protein increased unremarkably）,and the activities of SOD,POD,CAT were increased at first and then decreased by the extension of salt stress time.[Conclusion]These indicated that Celtis sinensis had some adapt ability to moderate salt osmotic stress by regulating the internal osmotic adjustment solute and activities of defense enzymes,but the salt osmotic stress with high concentration and long time might lead to severe damage on Celtis sinensis.