Molecular cloning of rice cDNAs related to pollen development using the subtraction hybridization technique

The meiotic stage of pollen mother cell is a very important stage in controlling the development and formation of pollen. In order to clone the rice cDNA(s) of this stage, a normal rice, Annong N and its thermosensitive mutant, Annong S-1 were used as the plant material. The mRNA has been extracted from the young panicle at the meiotic stage. By using the cDNA subtraction hybridization technique, three cDNA fragments,RP-1, RP-2 andRP-3 have been successfully cloned from Annong N. Northern blot analysis reveals that the mRNA of these three clones are expressed only in anthers, and not leaves. The mRNA levels of these clones are lower in anthers of Annong S-1 than in Annong N. Furthermore, the amount of mRNA extracted from anthers of Annong S-1 growing under high temperature (28°C) is lower than plants growing at lower temperature (25°C). Sequence analysis and homology search indicate that these three clones display no similanty to the current database. It is concluded that the three novel cDNA cloned are related to pollen development in rice.