Genome-Wide Characterization of Tomato FAD Gene Family and Expression Analysis under Abiotic Stresses

The fatty acid desaturase (FAD) gene family plays a crucial regulatory role in the resistance process of plant biomembranes. To understand the role of FADs in tomato growth and development, this study identified and analyzed the tomato FAD gene family based on bioinformatics analysis methods. In this study, 26 SlFADs were unevenly distributed on 10 chromosomes. Phylogenetic analysis showed that the SlFAD gene family was divided into six branches, and the exon–intron composition and conserved motifs of SlFADs clustered in the same branch were quite conservative. Several hormone and stress response elements in the SlFAD promoter suggest that the expression of SlFAD members is subject to complex regulation; the construction of a tomato FAD protein interaction network found that SlFAD proteins have apparent synergistic effects with SPA and GPAT proteins. qRT-PCR verification results show that SlFAD participates in the expression of tomato root, stem, and leaf tissues; SlFAD8 is mainly highly expressed in leaves; SlFAD9 plays a vital role in response to salt stress; and SlFAB5 regulates all stages of fruit development under the action of exogenous hormones. In summary, this study provides a basis for a systematic understanding of the SlFAD gene family. It provides a theoretical basis for in-depth research on the functional characteristics of tomato SlFAD genes.