An increase in unsaturation of fatty acids in phosphatidylglycerol from leaves improves the rates of photosynthesis and growth at low temperatures in transgenic rice seedlings.
The level of cis-unsaturated fatty acids in phosphatidylglycerol (PG) from rice leaves was genetically altered from 19.3% in the wild-type to 29.4 and 32.0% in T1 plants segregated with cDNAs for glycerol-3-phosphate acyltransferase of chloroplasts (GPAT; EC 2.3.1.15) from Arabidopsis (+AGPAT plant) and spinach (+SGPAT plant), respectively; and to 21.4% in a non-transformant segregated from +SGPAT plants (-SGPAT plant). In all these plants, O2 evolution from leaves was similar at 25 degrees C and was impaired to a similar extent at 5 and 11 degrees C. However, in parallel with the levels of cis-unsaturated fatty acids in PG, +AGPAT and +SGPAT plants showed less impaired rates of O(2) evolution from leaves than the wild-type and -SGPAT plants at 14 and 17 degrees C. In agreement with this, the fresh weight of 14-day-old seedlings increased to 571 + or - 18, 591 + or - 23, 687 + or - 32 and 705 + or - 31 mg in the wild-type, -SGPAT, +AGPAT and +SGPAT plants, respectively, after 6 weeks at 17/14 degrees C (day/night). These results demonstrate the practical importance of the present technology with GPAT in improvement of the chilling sensitivity of crops.
Ariizumi
Tohru
T
Laboratory of Plant Breeding and Genetics, Graduate School of Agricultural Science, Tohoku University, Aoba-ku, Sendai, 981-8555 Japan.
Kishitani
Sachie
S
Inatsugi
Rie
R
Nishida
Ikuo
I
Murata
Norio
N
Toriyama
Kinya
K
D017360:Arabidopsis / Q000201:enzymology; D002736:Chloroplasts / Q000201:enzymology / Q000235:genetics; D003080:Cold Temperature; D005231:Fatty Acids, Unsaturated / Q000378:metabolism*; D005992:Glycerol-3-Phosphate O-Acyltransferase / Q000235:genetics / Q000378:metabolism; D012275:Oryza / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D010100:Oxygen / Q000378:metabolism; D010715:Phosphatidylglycerols / Q000378:metabolism*; D010788:Photosynthesis / Q000502:physiology*; D018515:Plant Leaves / Q000378:metabolism*; D030821:Plants, Genetically Modified; D018724:Spinacia oleracea / Q000201:enzymology; D013997:Time Factors
D005231:Fatty Acids, Unsaturated; D010715:Phosphatidylglycerols; D005992:Glycerol-3-Phosphate O-Acyltransferase; D010100:Oxygen