Transgenic Rice Expressing Ictb and FBP/Sbpase Derived from Cyanobacteria Exhibits Enhanced Photosynthesis and Mesophyll Conductance to CO2.
To find a way to promote the rate of carbon flux and further improve the photosynthetic rate in rice, two CO2-transporting and fixing relevant genes, Ictb and FBP/Sbpase, which were derived from cyanobacteria with the 35SCaMV promotor in the respective constructs, were transformed into rice. Three homologous transgenic groups with Ictb, FBP/Sbpase and the two genes combined were constructed in parallel, and the functional effects of these two genes were investigated by physiological, biochemical and leaf anatomy analyses. The results indicated that the mesophyll conductance and net photosynthetic rate were higher at approximately 10.5-36.8% and 13.5-34.6%, respectively, in the three groups but without any changes in leaf anatomy structure compared with wild type. Other physiological and biochemical parameters increased with the same trend in the three groups, which showed that the effect of FBP/SBPase on improving photosynthetic capacity was better than that of ICTB and that there was an additive effect in ICTB+FBP/SBPase. ICTB localized in the cytoplasm, whereas FBP/SBPase was successfully transported to the chloroplast. The two genes might show a synergistic interaction to promote carbon flow and the assimilation rate as a whole. The multigene transformation engineering and its potential utility for improving the photosynthetic capacity and yield in rice were discussed.
State Key Laboratory for Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, China; Engineering Research Centre for the Protection and Utilization of Bioresource in Ethnic Area of Southern China, South-Central University for Nationalities, Wuhan, China.
Han Yu
HY
Gong
State Key Laboratory for Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, China.
Yang
Y
Li
State Key Laboratory for Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, China.
Gen
G
Fang
State Key Laboratory for Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, China.
Dao Heng
DH
Hu
State Key Laboratory for Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, China.
Wen Bin
WB
Jin
State Key Laboratory for Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, China.
Zhao Hai
ZH
Wang
State Key Laboratory for Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, China.
Yang Sheng
YS
Li
D016960:Agrobacterium tumefaciens / Q000235:genetics; D027321:Anion Transport Proteins / Q000235:genetics*; D001426:Bacterial Proteins / Q000235:genetics*; D001692:Biological Transport / Q000235:genetics; D002245:Carbon Dioxide / Q000378:metabolism; D027682:Cation Transport Proteins / Q000235:genetics*; D002736:Chloroplasts / Q000235:genetics / Q000378:metabolism; D000458:Cyanobacteria / Q000201:enzymology / Q000235:genetics*; D035264:Flowers / Q000235:genetics; D006597:Fructose-Bisphosphatase / Q000235:genetics*; D058503:Mesophyll Cells / Q000378:metabolism; D012275:Oryza / Q000033:anatomy & histology / Q000235:genetics*; D010788:Photosynthesis / Q000235:genetics*; D018515:Plant Leaves / Q000033:anatomy & histology; D030821:Plants, Genetically Modified / Q000235:genetics
D027321:Anion Transport Proteins; D001426:Bacterial Proteins; D027682:Cation Transport Proteins; D002245:Carbon Dioxide; D006597:Fructose-Bisphosphatase