ANALYSIS OF RANDOMLY ISOLATED CDNAS FROM DEVELOPING ENDOSPERM OF RICE(ORYZA-SATIVA L) - EVALUATION OF EXPRESSED SEQUENCE TAGS, AND EXPRESSION LEVELS OF MESSENGER-RNAS

Using a cDNA library prepared from poly(A)(+) RNA from 10-day-old rice endosperm, partial nucleotide sequences of randomly isolated clones w ere analyzed. A total of 153 (30.6%) out of 500 cDNA clones showed hig h amino acid identity to previously identified genes. There was signif icant redundancy in cDNAs encoding prolamine and glutelin. About 21.0% of the cDNA clones were found to code for seed storage protein genes. Consequently, 37 independent genes were identified. Using cDNA clones encoding glutelin, prolamine, seed allergen, alpha-1,4-glucan branchi ng enzyme, glycine-rich RNA binding protein, metallothionein, non-spec ific lipid-transfer protein and ubiquitin conjugating enzyme the accum ulation of mRNA during rice seed development was compared. Genes assoc iated with seed storage protein and starch biosynthesis were expressed according to expected developmental stages. Glycine-rich RNA binding protein genes as well as metallothionein-like protein genes were highl y expressed in developing seeds, but low in leaves of whole plants.