Characterization and Expression of RUB1 Conjugase and Cullin1-like Genes in Poplar Associated with Vegetative Bud Development and Dormancy

Abstract

Dormancy is an adaptive trait that ensures survival of plants in adverse growth conditions. By using phylogenetical, expression, and protein analysis, RUB1 conjugase and Cullin1 were characterized in poplar dormancy. RUB1 conjugase and Cullin1 were annotated using sequence homology approach. RUB1 conjugase was expressed in apical buds during dormancy but not detected in those of etr1-1 expressing poplars. Its transcript abundance was reduced in axillary buds, leaves and bark of etr1-1 expressing poplars compared to wild types. RUB1 conjugase expression was not affected by AVG but reduced by 50µM ACC in apical buds of etr1-1 expressing poplars. Cullin1 and EBF expression did not display significant difference in most tissues except for the Cullin1 expression in middle and bottom leaves during short-day treatments in wild types. Two novel RUB1-conjugated proteins were detected during low temperature treatments. This study has built a foundation for further analysis of targeted protein degradation in dormancy.