title: Effects of salinities on the gene expression of a (NAD+)-dependent glycerol-3-phosphate dehydrogenase in Dunaliella salina.
abstract: Glycerol-3-phosphate dehydrogenase (G3pdh) is a key enzyme in the pathway of glycerol synthesis, which converts dihydroxyacetone phosphate (DHAP) to glycerol-3-phosphate. In this study, the effects of salinity changes on variation of cell shape and single cell glycerol content of Dunaliella salina were observed, and the 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, but when the salinity was changed rapidly, the variations of cell shape and cell volume of D. salina were significant, which were recovered basically after 2h except treating by high salinity. Also, it was found some lipid globules in the surface of D. salina cells when the salinity increased from 2.0 to 4.0-5.0 M 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 to the salinity, but there was no significant correlation between the expression level of G3pdh and salinity after 2 h of treatment by hyperosmotic or hypoosmotic shock.
authors.affiliation: College of Food and Bioengineering, South China University of Technology, Guangzhou 510640, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Chen
authors.forename: Yong-Min
authors.initials: YM
authors.lastname: Lao
authors.forename: Jian-Guo
authors.initials: JG
authors.lastname: Jiang
mesh_terms: D048430:Cell Shape / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D015870:Gene Expression / Q000187:drug effects*; D050536:Glycerol-3-Phosphate Dehydrogenase (NAD+) / Q000235:genetics* / Q000378:metabolism; D054712:Salinity; D012965:Sodium Chloride / Q000633:toxicity*; D013312:Stress, Physiological; D016823:Volvocida / Q000187:drug effects / Q000235:genetics* / Q000502:physiology; D014874:Water Pollutants, Chemical / Q000633:toxicity*; D014882:Water-Electrolyte Balance / Q000235:genetics
chemical_list: D014874:Water Pollutants, Chemical; D012965:Sodium Chloride; D050536:Glycerol-3-Phosphate Dehydrogenase (NAD+)