| dc.description.abstract | This study aimed to investigate the correlation between callus regeneration rate and the expression of several
genes responsible for cytokinin response and ethylene biosynthesis in the Ciherang, Mentik Wangi Susu, Hwayoung and
Tarabas rice varieties. The callus regeneration rate of each rice variety was in vitro tested using N6 media, while the gene
expression during the callus regeneration stages was examined using quantitative real‐time PCR (qRT‐PCR). Our results
showed that the callus of Ciherang and Mentik Wangi Susu showed earlier green spot formation that then turned brown
at a later stage, resulting in a low regeneration rate. While Hwayoung and Tarabas showed late green spot formation, high
shoot regeneration was observed in both calluses. Gene expression analysis of regeneration media‐grown calluses showed
that two cytokinin‐responsive genes, OsRR2 and OsRR6, were highly expressed in the Ciherang and Hwayoung callus,
respectively. We also observed that ethylene biosynthesis genes such as OsACS1 and OsACO1 were highly expressed in the
Mentik Wangi Susu and Hwayoung callus, respectively. Moreover, the expression of OsBBM1 was high in Hwayoung and
Tarabas. Thus, the positive correlation between the expression of cytokinin‐responsive and ethylene biosynthesis genes
with somatic embryogenesis activity likely depends on the induction level of OsBBM1. | en_US |
