NaCl浓度对杜氏盐藻中1种NAD^+依赖的3-磷酸甘油脱氢酶基因表达的影响

Effects of salinities on gene expression of a(NAD+)-dependent glycerol-3-phosphate dehydrogenase in Dunaliella salina

考察NaCl浓度变化对杜氏盐藻细胞形态和单细胞甘油含量变化的影响,并应用实时定量PCR技术检测NaCl浓度变化对杜氏盐藻3-磷酸甘油脱氢酶同工酶中1种NAD+依赖的3-磷酸甘油脱氢酶基因表达的影响。结果表明:不同浓度NaCl长期培养时杜氏盐藻细胞形态和体积的变化较小,但当NaCl浓度快速变化时细胞形态和体积变化显著。杜氏盐藻在不同浓度NaCl条件下长期培养,随着NaCl浓度增长,单细胞甘油含量不断积累,且杜氏盐藻能通过快速降低或提高单细胞甘油含量来应对低渗或高渗震动。不同浓度NaCl长期培养时,杜氏盐藻中3-磷酸甘油脱氢酶基因的表达水平与NaCl浓度呈显著负相关,但低渗或高渗震动处理2 h后,3-磷酸甘油脱氢酶基因的表达水平与NaCl浓度无显著性关系。

Effects of salinity changes on variation of cell shape and single cell glycerol content of Dunaliella salina were investigated and effects of salinity changes on the gene expressions of a（NAD＋）-dependent G3pdh（EC1.1.1.8） among G3pdh isozymes in D.salina were detected by real-time quantitative PCR.Results showed that the changes of shape and volume of D.salina cell cultured chronically at various salinities were minor.When the salinity changed rapidly,the variations of cell shape and cell volume of D.salina were significant,which were recovered basically after 2 h except treated by high salinity.It was found that some lipid globules in the surface of D.salina cells when the salinity increased from 2.0 to 4.0-5.0 mol/L NaCl rapidly.When D.salina was cultured chronically at various salinities,the accumulation of single cell glycerol increased with increased salinity,and D.salina also could rapidly decrease or increase single cell glycerol contents to adapt to hypoosmotic or hyperosmotic shock.The expression level of G3pdh in D.salina grown at various salinities was significantly inversely correlated with the salinity.There was no significant correlation between the expression level of G3pdh and salinity after two hours of treatment by hyperosmotic or hypoosmotic shock.