Overexpression of sweet pepper glycerol-3-phosphate acyltransferase gene enhanced thermotolerance of photosynthetic apparatus in transgenic tobacco.
In order to investigate the relationship between the lipid composition in thylakoid membrane and thermostability of photosynthetic apparatus, tobacco transformed with sweet pepper sense glycerol-3-phosphate acyltransferase (GPAT) gene were used to analyze the lipid composition in thylakoid membrane, the net photosynthetic rate and chlorophyll fluorescence parameters under high temperature stress. The results showed that the saturated extent of monogalactosyldiacylglycerol (MGDG), sulfoquinovosyldiacylglycerol, digalactosyldiacylglycerol and phosphatidylglycerol in thylakoid membrane of transgenic tobacco T(1) lines increased generally. Particularly, the saturated extent in MGDG increased obviously by 16.2% and 12.0% in T(1)-2 and T(1)-1, respectively. With stress temperature elevating, the maximum efficiency of photosystem II (PSII) photochemistry (Fv/Fm), actual photochemical efficiency of PSII in the light (Phi(PSII)) and net photosynthetic rate (Pn) of the two lines and wild type tobacco plants decreased gradually, but those parameters decreased much less in transgenic plants. Even though the recovery process appeared differently in the donor and acceptor side of PSII in transgenic tobacco compared with wild-type plants, the entire capability of PSII recovered faster in transgenic tobacco, which was shown in the parameters of PI, Fv/Fm and Phi(PSII), as a result, the recovery of Pn was accelerated. Conclusively, we proposed that the increase in saturated extent of thylakoid membrane lipids in transgenic plants enhanced the stability of photosynthetic apparatus under high temperature stress.
Yan
Kun
K
College of Life Sciences, State Key Laboratory of Crop Biology, Shandong Agricultural University, Tai'an 271018, China.
Chen
Na
N
Qu
Yan-Yan
YY
Dong
Xin-Chun
XC
Meng
Qing-Wei
QW
Zhao
Shi-Jie
SJ
D000222:Adaptation, Physiological; D015152:Blotting, Northern; D002212:Capsicum / Q000201:enzymology*; D004579:Electron Transport; D005227:Fatty Acids / Q000032:analysis; D018506:Gene Expression Regulation, Plant; D005992:Glycerol-3-Phosphate O-Acyltransferase / Q000235:genetics*; D008563:Membrane Lipids / Q000737:chemistry; D010788:Photosynthesis; D030821:Plants, Genetically Modified; D013696:Temperature; D020524:Thylakoids / Q000737:chemistry; D014026:Nicotiana / Q000201:enzymology* / Q000235:genetics*
D005227:Fatty Acids; D008563:Membrane Lipids; D005992:Glycerol-3-Phosphate O-Acyltransferase