Xiang-Ming Wang, Ming-Jie Zhou and Yi-Cheng Cao
Genetics Laboratory, Biology Dept., Wuhan University, Wuchang, Hubei, China
GOT (E.C.126.96.36.199) plays an important role in amino-acid metabolism and protein synthesis in plants. Its variation in rice species was reported by Second and Trouslot (1980), who postulated that 14 different zymograms observed among plants of O. longistaminata and other species with genome AA could be governed by three loci each with two active alleles. However, we found that rice cultivars and their wild relatives were nearly monomorphic in GOT zymogram, and that species with different genomic constitutions had different zymograms.
Fully-expanded leaf blades were used for analysis. The leaf blades, 1 g per sample, were ground in an ice-bath with 1 ml of distilled water. Electrophoresis was made on polyacrylamide gels in glycine buffer by using an SCR-4 apparatus.
A total of 11 bands with Rf. values ranging from 0.135 to 0.535 were identified. All of 31 strains belonging to species with genome AA (O. sativa, O. sativa f. spontanea, O. perennis, O. glaberrima, and O. barthii) uniformly showed four bands at 3A, 5A, 6A, and 9A positions. But the zymograms were genome-specific, as shown in Table 1. The data suggest that GOT isozymes reflect the phylogenetic relationships of species in terms of genomic differentiation.
Table 1. Zymograms of species with different genomes. ============================================================================== Genome Species No. of Band identified samples 1A 2A 3A 4A 5A 6A 7A 8A 9A 10A 11A (Rf:.175 .20 .22 .29 .305 .355 .365 .45 .47 .505 .535) ============================================================================== CCDD latifolia; 4 + + + + + + alta BBCC minuta; 4 + + + + + + punctata CC officinalis 7 + + + + + EE australiensis 2 + + + FF brachyantha 1 + + AA sativa; etc. 31 + + + + (in text) ==============================================================================
Second, G. et P. Trouslot, 1980. Electrophorese d'enzymes de riz (Oryza spp.). Polymorphisme de treize zymogrammes observes parmi diverses especes sauvages et cultivees du genre Oryza. Travaus et Documents 120, ORSTOM, Paris 88pp.