Functional expression of the Erwinia uredovora carotenoid biosynthesis gene crtl in transgenic plants showing an increase of beta-carotene biosynthesis activity and resistance to the bleaching herbicide norflurazon.
Among the enzymes involved in carotenoid biosynthesis, phytoene desaturase is considered to be a rate-limiting enzyme in this pathway and is also the target of many bleaching herbicides. This enzyme shows diversity concerning its function and amino acid homology among various organisms. The phytoene desaturase gene crtl of Erwinia uredovora was expressed, the 5'-region of which was fused to the sequence for the transit peptide of a pea Rubisco small subunit, in tobacco plants under the control of the CaMV 35S promoter. This chimeric gene product was targeted into chloroplasts and processed in the transgenic plants. The production and processing of the corresponding protein could be demonstrated by Western blotting. Immunogold localization showed that the location of the gene product Crtl was preferentially in the thylakoids. A radioactive labeling study using the leaves demonstrated enhanced activity for the synthesis of beta-carotene. In addition, the transgenic tobacco acquired elevated resistance to the bleaching herbicide norflurazon.
Misawa
N
N
Central Laboratories for Key Technology, Kirin Brewery Co., Ltd, Yokohama-shi, Japan.
Yamano
S
S
Linden
H
H
de Felipe
M R
MR
Lucas
M
M
Ikenaga
H
H
Sandmann
G
G
D000595:Amino Acid Sequence; D001483:Base Sequence; D002338:Carotenoids / Q000096:biosynthesis* / Q000378:metabolism; D002736:Chloroplasts / Q000201:enzymology; D004351:Drug Resistance; D004885:Erwinia / Q000201:enzymology* / Q000235:genetics; D005798:Genes, Bacterial; D006540:Herbicides / Q000494:pharmacology*; D007150:Immunohistochemistry; D007425:Intracellular Membranes / Q000201:enzymology; D008969:Molecular Sequence Data; D010088:Oxidoreductases / Q000096:biosynthesis* / Q000235:genetics / Q000302:isolation & purification; D030821:Plants, Genetically Modified / Q000187:drug effects; D010947:Plants, Toxic; D011498:Protein Precursors / Q000096:biosynthesis / Q000235:genetics; D021382:Protein Sorting Signals / Q000096:biosynthesis / Q000235:genetics; D011724:Pyridazines / Q000494:pharmacology*; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis / Q000235:genetics; D012273:Ribulose-Bisphosphate Carboxylase / Q000096:biosynthesis / Q000235:genetics; D014026:Nicotiana / Q000187:drug effects* / Q000235:genetics; D019207:beta Carotene
D006540:Herbicides; D011498:Protein Precursors; D021382:Protein Sorting Signals; D011724:Pyridazines; D011993:Recombinant Fusion Proteins; D019207:beta Carotene; D002338:Carotenoids; C100185:(all-E) phytoene; D010088:Oxidoreductases; C022398:phytoene dehydrogenase; D012273:Ribulose-Bisphosphate Carboxylase; C008677:norflurazone