Molecular cloning and sequence analysis of two GA2ox genes in Pseudostellariae Radix / 中草药

ABSTRACT

Objective: To clone the gibberellin 2-oxidase (GA2ox) genes from Pseudostellaria heterophylla and perform the bioinformatic and expression mode analysis. Methods: According to P. heterophylla transcriptome annotation, two transcript codings of GA2ox were identified. The full-length cDNA PhGA2ox1 and PhGA2ox8 were determined using RT-PCR. Then the bioinformatic analysis of these genes and encoded proteins were performed. The coding sequences of PhGA2ox1 and PhGA2ox8 were amplified by PCR. And then analyzed the bioinformation of these sequences. The expression levels of PhGA2ox1 and PhGA2ox8 were analyzed using qPCR. Results: Bioinformatic analysis showed that PhGA2ox1 contained 981 bp and encoded a predicted protein of 326 amino acids with molecular weight of 36 871.3 and isoelectric point (PI) of 8.66; PhGA2ox8 contained 1 056 bp and encoded a predicted protein of 351 amino acids with molecular weight of 40 169.9 and PI of 6.91. Both PhGA2ox1 and PhGA2ox8 contained GA2ox conserved domains DIOX_N and 20G-Fell_Oxy, without obvious hydrophobic region, transmembrane domain and signal peptide. Phylogenetic analysis showed that the GA2ox of plant could be divided into three classes, PhGA2ox1 bolongs to Class I and PhGA2ox8 belongs to Class III. The qPCR. showed that the expression of PhGA2ox1 in different tissues and organs of P. heterophylla was constant, but the expression of PhGA2ox8 in root xylem was significantly higher than that in other tissues and organs (P < 0.05). Conclusion: The PhGA2ox1 and PhGA2ox8 genes are cloned for the first time, and provide a foundation for they may play an important role in the growth and development process of P. heterophylla.