Dense-panicle-related gene cloning from rice mutant A989 and transgenic plant analysis.

Abstract Flowering time and inflorescence architecture are important and inter-relating traits in rice ( Oryza sativa L.). Overexpression of each of RCN1 to RCN3 in rice could result in delayed flowering and abnormal inflorescence architecture. From a transferred DNA (T-DNA) insertion population constructed from japonica rice cv. Zhonghua 11, a mutant, A989, exhibiting dense panicle and late flowering was isolated. Genetic and molecular analysis showed that a single copy of T-DNA was inserted into the genome of the mutant, and the T-DNA was inserted into the 330 bp position after RCN2 poly A. Overexpression of RCN2 was observed in the mutant as revealed by reverse transcription-polymerase chain reaction (RT-PCR) test. When RCN2 gene was transferred into wild type driven by double 35S promoters, the transformants showed no panicle due to the suspensions of differentiation and growth of the secondary-branch primordium; however, the transition from vegetative growth to productive growth was normal in the transgenic plant.