甘蔗ScGID2基因的克隆鉴定及其在赤霉素信号转导中的表达调控模式分析OA

Internode length is a key factor determining sugarcane plant height,and appropriate promotion of sugarcane internode elongation can increase unit yield.The gibberellin insensitive dwarf(GID)gene is a core receptor in the gib-berellin(GA)signaling pathway.Previous studies have shown that sugarcane GID1 is highly expressed during the vig-orous internode elongation stage,and its overexpression can enhance GA signaling to promote internode elongation.In this study,using the sugarcane variety Guitang 42,Xintaitang 22,Guifu 98-296 as the material,the coding sequence(CDS)of ScGID2(gibberellin receptor protein)was cloned and subjected to bioinformatics analysis.Besides,quantita-tive real-time PCR(qRT-PCR)was used to analyze the expression patterns of the gene in different tissues,different genotypic varieties,and under gibberellin(GA3)treatment.Result showed that the cloned ScGID2 gene had a full-length CDS of 720 bp,encoding 239 amino acids,containing a conserved F-box domain.It shared high homology(>88.75%)with GID2 from gramineous plants such as sorghum and maize,and was mainly localized in the nucleus.Expression pattern analysis revealed that ScGID2 had the highest expression level in the shoot apex at the non-elongation stage,followed by the+2 internode at the vigorous elongation stage.There were differences in the expression patterns of ScGID2 among different sugarcane varieties.The expression of ScGID2 in Xintaitang 22,Guifu 98-296,and Guitang 43 showed a trend of first increasing,then decreasing,then increasing again,and then decreasing again.The expression level of ScGID2 in Guitang 43 was much higher than that in Xintaitang 22 and Guifu 98-296.The expression level of ScGID2 in Guitang 42 increased gradually,reaching the peak at 30 days.The expression peak of ScGID2 in long-internode varieties was significantly higher than that in short-internode varieties and lasted longer.After GA3 treatment,the expression peak of ScGID2 in the short-internode variety Guitang 14-818 appeared earlier than that in the long-internode variety Guifu 98-296.Taken together,the present study provides a theoretical basis for elucidating the molecular mechanism of gibberellin-mediated sugarcane internode elongation,and ScGID2 could serve as a potential molecular target for sugarcane plant height improvement,since the expression of ScGID2 is induced by gibberellin and positively correlated with the internode elongation rate.