马尾松蔗糖磷酸合酶基因的克隆和表达分析.

To determine function and expression patterns of the sucrose phosphate synthase（SPS） gene in Masson pine（Pinus massoniana Lamb.),four sucrose phosphate synthase genes（PmSPS1 to PmSPS4） were studied. The four SPS genes were identified using Masson pine transcriptome data and were cloned from Masson pine. Bioinformatic analysis was conducted and the relative expressions of the genes were detected by qRT-PCR in different tissues, different-yield oleoresin germplasm, and following stress caused by low levels of phosphorus. The open reading frames of the genes ranged from 1 701 to 3 243 bp, encoding 566 to 1 080 amino acids. Phylogenetic tree analysis confirmed that PmSPS1 and PmSPS3 belonged to subfamily A, with PmSPS2 and PmSPS4 in subfamily B. Tissue-specific expression analysis revealed that PmSPS2 and PmSPS4 were most highly expressed in needles, with PmSPS1 and PmSPS3 obviously expressed in bark. The expression of PmSPS1 and PmSPS3 did not highly differ between young and mature tissues. The expressions of PmSPS2 and PmSPS4 were significantly higher（P<0.05） in mature needles than in young needles, while there were no significant changes between young and mature stems. In addition, the expression levels of PmSPS1 and PmSPS3 were not significantly different between high and low-yield oleoresin germplasm, while the expression levels of PmSPS2 and PmSPS4 in needle of high-yield oleoresin germplasm were higher than those of low-yield oleoresin germplasm and lower in high-yield oleoresin xylem than in low-yield. The expression levels of all four PmSPS genes were up-regulated in needles in the presence of low phosphorus. PmSPS2 expression was the highest, being 3.18 times higher than that of the control. The collective results showed that the four SPS genes obtained by cloning were distributed in subfamilies A and B. The genes of different subfamilies showed different expression characteristics. The results provide a theoretical basis for the subsequent in-depth study of the functions of SPS family genes in Masson pine [ABSTRACT FROM AUTHOR]