Isolation of cDNA clones for genes that are specifically expressed in the rice embryo

Abstract

We isolated thirty-eight cDNA clones representing genes expressed in the rice embryo by differential screening of a cDNA library made with poly(A) RNA from embryos at the stage of 10-days after pollination. Eighteen cDNA clones displayed either a significant nucleic acid or amino acid sequence similarity to sequences known in the GenBank, i.e., two rice oleosins, four globulin or glutelin-like proteins, two ABA response proteins, two LEA-like proteins, one trypsin inhibitor, one metallothionein-like protein, one protein kinase, one leucine-zipper containing protein, one proline-rich protein, and three genes of unknown function. Experimental results indicated the presence of redundant cDNA clones for genes that produced an abundant amount of mRNAs in the embryo. RNA slat blot hybridization demonstrated the embryo-specific expression for thirty-seven cDNA clones. The majority of the identified cDNAs had not been known in rice. Results in this study contribute toward the on-going attempt to isolate embryo-specific and novel genes in rice.