Genome-Wide Identification and Expression Analysis of the SUT Family from Three Species of Sapindaceae Revealed Their Role in the Accumulation of Sugars in Fruits.

is an economically important family of Sapindales and includes many fruit crops. The dominant transport and storage form of photoassimilates in higher plants is sucrose. Sucrose transporter proteins play an irreplaceable role in the loading, transportation, unloading, and distribution of sucrose. A few (sugar transporter) family genes have been identified and characterized in various plant species. In this study, 15, 15, and 10 genes were identified in litchi, longan, and rambutan, respectively, via genome-wide screening. These genes were divided into four subgroups based on phylogenetics. Gene duplication analysis suggested these genes underwent potent purifying selection and tandem duplications during evolution. The expression levels of and were significantly increased in the fruits of members. The homologs of these two genes in longan and rambutan were also highly expressed in the fruits. The expression pattern of s in three organs of the two varieties was also explored. Subcellular colocalization experiments revealed that the proteins encoded by both genes were present in the plasma membrane. This report provides data for the functional study of s in litchi and provides a basis for screening sugar accumulation-related genes in fruits of .