研究了室温〔（25±1） ℃〕贮藏、低温〔（4±1） ℃〕贮藏、1-甲基环丙烯（1-MCP）处理和减压浸钙处理条件下‘槜李’（Prunus salicina ‘Zuili’）果实硬度的动态变化，进一步克隆获得‘槜李’的多聚半乳糖醛酸酶基因（PsPG），并对该基因进行了生物信息学和表达分析。结果表明：低温贮藏、1-MCP处理和减压浸钙处理可有效减缓‘槜李’果实硬度下降。‘槜李’PsPG基因的开放阅读框（ORF）长度为1 134 bp，编码377个氨基酸。PsPG蛋白的二级结构由11.14％的α螺旋、3103％的β折叠和57.82％的无规则卷曲构成。生物信息学分析结果显示：PsPG蛋白含有果胶酸裂解酶3结构域和4个PbH1结构域；PsPG基因与Prunus persica （Linn.） Batsch和Prunus armeniaca Linn.的PG基因编码的氨基酸序列的亲缘关系较近，相似度达96％以上。qRT-PCR分析结果显示：随着采后贮藏时间的延长，低温贮藏、1-MCP处理和减压浸钙处理条件下PsPG基因的相对表达量均呈先升高后降低的趋势，且分别于贮藏5、3和5 d达到最高值。研究结果显示：‘槜李’PsPG基因与其果实软化关系密切，低温贮藏是‘槜李’果实采后保鲜的有效手段，可抑制PsPG基因的表达以延缓果实软化。

Dynamic changes in fruit firmness of Prunus salicina ‘Zuili’ in the conditions of room temperature 〔（25±1） ℃〕 storage， low temperature 〔（4±1） ℃〕 storage， 1-methylcyclopropene （1-MCP） treatment， and immersed in Ca2+solution with decompression treatment were studied， polygalacturonase gene （PsPG） from P. salicina ‘Zuili’ was cloned， and its bioinformatics and expression were analyzed. The results show that low temperature storage， 1-MCP treatment， and immersed in Ca2+ solution with decompression treatment can effectively retard the decrease of fruit firmness of P. salicina ‘Zuili’. The length of open reading frame. （ORF） of PsPG gene from P. salicina ‘Zuili’ is 1 134 bp， which encodes 377 amino acids. The secondary structure of PsPG protein includes 11.14％ of α helix， 31.03％ of β sheet， and 57.82％ of random coil. The result of bioinformatics analysis shows that PsPG protein has pectate lyase 3 domain and four PbH1 domains； the relationships among amino acid sequences encoded by PsPG gene and PG genes from Prunus persica （Linn.） Batsch and Prunus armeniaca Linn. are close， with similarity more than 96％. The result of qRT-PCR analysis shows that with prolonging of postharvest storage time， all relative expressions of PsPG gene increase firstly and then decrease in the conditions of low temperature storage， 1-MCP treatment， and immersed in Ca2+ solution with decompression treatment， and reach the peak value when stored for 5， 3， and 5 d， respectively. It is suggested that PsPG gene from P. salicina ‘Zuili’ has a close relationship with its fruit softening， low temperature storage is effective measure to retain freshness of fruit of P. salicina ‘Zuili’ after harvest， which can inhibit expression of PsPG gene to postpone fruit softening.