Two cDNA libraries were constructed from microdissected 214 rice proembryos (2-3 d after pollination) and 121 just differentiating young embryos (3-5 d after pollination) respectively through RT_PCR technique. The primary libraries had a total of 3.7×10 6 phages for the proembryos and a total of 2.5×10 6 phages for the just differentiating young embryos, in which 96% of the phages were recombinants. Insert sizes ranging from 400 bp to 3?500 bp were obtained. All of the above mentioned accorded with the general requirements of cDNA library construction.
A mRNA whole_mount in situ hybridization method is reported here for quick, direct analysis of the spatial and temporal mRNA expression patterns in plant young embryos. A cDNA clone THE 3 (tobacco heart embryo 3) was isolated by differential screening from tobacco (Nicotiana tabacum L.) heart embryo cDNA library as compared with the globular embryo cDNA library. The distribution of THE 3 mRNA in tobacco heart embryos and globular embryos was investigated by a whole_mount in situ hybridization technique, showing that THE 3 is preferentially expressed in heart embryos.
