关键词: 砂梨, 山梨醇转运蛋白（SOT）, 基因家族, 表达特性, 果实, 糖

Abstract: Sorbitol transporter（SOT）is an essential carrier for sorbitol transport in plants. A total of 22 expressed PpySOT members were identified from sand pear（Pyrus pyrifolia Nakai.）flesh by a RNA-seq analysis using Chinese white pear（P. bretschneideri Rehd.）genome as reference，with the top 10 members accounting for 92% of total transcript abundance. Tissue-specific expression patterns of these 10 members were observed via qRT-PCR. All members barely expressed in seed，PpySOT8 expressed in all tissues analysed，while the expression of PpySOT26 was mostly restricted in young leaves. The transcriptabundance of PpySOT2，PpySOT8，PpySOT10/28 and PpySOT33 was in a close positive correlation with sorbitol accumulation during fruit development. The content of sorbitol in flesh decreased during cold storage at 4 ℃，and it was related to the increased expression of PpySOT3，PpySOT4，PpySOT8，PpySOT25，PpySOT32 and PpySOT33.

Key words: Pyrus pyrifolia, sorbitol transporter（SOT）, gene family, expression characteristic, fruit, sugar