Abstract:

To further explore the biological function of rice polyembryo candidate gene OsPE,Oryza sativa ssp.Japonica cv.Nipponbare and Indica cv.Basmati 370 was taken as the research materials, and the mature leaves of the test materials under normal growth conditions were employed.Bioinformatics,RT-PCR,TA cloning,semi-quantitative,and qPCR were used to identify and analyze the splicers of OsPE.The bioinformatics analysis showed three kinds of variable splices of OsPE in Japonica rice and no variable splices in Indica rice.But the existence of three variable splices of the OsPE gene was identified in Japonica rice.Two new variable splice variants were found in Indica rice through RT-PCR amplification with specific primers,combined with TA cloning and sequencing verification.Subsequently,the semi-quantitative and qPCR results showed differences in the expression of the variable splices of the OsPE gene.Moreover,the expression intensities are as follows:OsPEc>OsPEa>OsPEb,the gene had the same expression trend in different rice varieties.Finally,the evolutionary analysis and functional prediction of the protein encoded by the OsPE gene showed that the OsPE protein was highly conserved in Gramineae,especially in Oryza L.(percent identity was higher than 99%).It needs to be further studied whether this gene was involved in regulating rice's stress response,cell division,and apoptosis but not the regulation of rice polyembryony production.To sum up,the OsPE gene was highly conserved in Gramineae,especially in Oryza L..This gene had the same splicing pattern in Japonica and Indica rice.Its variable splices had different expressions under normal growth conditions,but the expression trend was the same,OsPEc spliceosome dominate the function of the OsPE gene.It needed to be further studied whether this gene was involved in regulating rice's stress response,cell division,and apoptosis but not the regulation of rice polyembryony production.

Key words: Rice, Polyembryo candidate gene, OsPE, Splice variants