Analysis of SERK1 Expression associated with Somatic Embryogenesis in Rice

Abstract

Somatic embryogenesis (SE) is used for rice improvement where in vitro production of somatic embryos are generated from somatic cells which later converted into whole plants. Finding embryogenic regenerable callus in certain developmental stages is the main step to achieve successful and efficient regeneration. Many indica rice has been shown to have recalcitrant in regeneration capacity; hence identification of embryogenic marker for regenerable competent cell/calli would be beneficial and fasten the processes. This study analysed the SERK1 expression in different calli which confer embryonic competence using semi-quantitative PCR followed by gene expression studies by realtime PCR. In this study, amplification of SERK1 gene from cDNA aged 21-days was successfully in all four rice varieties at approximately 200bp under study. The neighbour joining tree analysis showed those SERK1 genes of all varieties were similar to the SERK1 of Oryza sativa Japonica. The real-time PCR analysis revealed that SERK1 expression was highest from callus on treated MS media with 2,4-D at 45°C pre-heat treated seed of MR220, MR220-CL2, MR232, Bario. The study was also found that expression of SERK1 were highest between 21 to 28 days of callusing response and decreased after that. The profile of SERK1 expression in callus, vegetative organ and immature seeds were different in each variety. Our results indicated that SERK1 expression was associated with the induction of SE and closely related to PGR/ preheat during tissue culture, and the gene might play an important role in inducing callus.