Genome-wide identification and expression analysis of gibberellin biosynthesis, metabolism and signaling family genes in Phyllostachys edulis / 生物工程学报

ABSTRACT

Gibberellin is an essential plant hormone that plays an important regulatory role throughout the life cycle of higher plants. A total of 23 genes involved in gibberellin action were identified from Phyllostachys edulis genome, including 8 GA20ox and 1 GA3ox genes involved in the gibberellin biosynthesis, 8 GA2ox genes involved in the metabolism of gibberellin, 2 GID1 genes involved in gibberellin perception, 2 GID2 genes and 2 DELLA genes involved in gibberellin signal transduction. Phylogenetic analysis of these genes from Arabidopsis, Oryza sativa and Phyllostachys edulis revealed that gibberellin biosynthesis, metabolism, and signaling pathways are conserved in these species. Treatment of seeds and seedlings of bamboo with exogenous gibberellin revealed that gibberellin significantly increased seed germination rate and stem elongation of seedlings, and had the best concentration of action. The expression levels of GA20ox and GA3ox genes in the bamboo seedlings were down-regulated and the expression of the active gibberellin-degrading gene GA2ox was up-regulated after GA3 treatment, and the transcriptional level of the gibberellin receptor GID1 and the positive regulatory gene GID2 was significantly increased while the expression of the negative regulatory gene DELLA was decreased. These genes have significant differences in the expression of different spatial locations of bamboo shoot stems, GA20ox, GA3ox, GA2ox, GID1 and GID2 are all expressed in the upper part of bamboo shoots, while the repressor gene DELLA accumulates at the bottom of the shoots and is hardly expressed at the top.