Existence of homologous sequences corresponding to cDNA of the ver gene in diverse higher plant species

JIA Shi Qian¹, Wei Dong YONG¹, Wen Zhong XU¹, Yun Yuan XU¹, Jin Song WU¹, Kang CHONG^1,*, Ke Hui TAN¹, Zhi Hong XU^1,2

¹Research Center for Molecular and Developmental Biology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
² Chinese Academy of Sciences, Beijing 100864, China

The presence of DNA homologues corresponding to verc203 (vernalization-related cDNA clone) was investigated by molecular hybridization techniques. The genes were detected in 16 plant species that cover 12 subclasses of the Takhtajan system of angiosperms classification including diverse model species. The results of Southern blot analysis showed a low copy number of this gene existed in rice, wheat, barley and Arabidopsis. The hybridization result of PCR products demonstrated the conservation of the gene corresponding to ver203 in diverse plants. The phylogenetic tree of the ver203 gene in tested plants was supported by evolution relationship of species. The ver203 gene expressed in a vernalized plumule winter wheat, instead of the root. And the endosperm before the treatment was essential for the ver203 expression during vernalization in wheat. In Arabidopsis thaliana, the pattern of expression showed that the gene corresponding to ver203 was expressed at low temperature for 14 days. Gibberellin (GA₃) may accelerate the expression of ver203 gene in Arabidopsis exposed to low temperature. However, it could not replace vernalization treatment to initiate the gene expression.

Key words: Ver203 gene, vernalization-related gene, flower initiation, homologous DNA, Takhtajan system.