Analysis of the effect of improving drought tolerance via SlGATA17 overexpression on tomato fruit quality

• Validated drought resistance of SlGATA17 Overexpression. • Improved antioxidant capacity of tomato fruits and anthocyanin content. • Use of combined transcriptomic and metabolomic analyses. • SlGATA17 Overexpression has the potential to be applied to practical production. We previously showed that overexpression of the tomato SlGATA17 gene can increase drought tolerance and phenylpropanoid biosynthesis in tomato plants, this method has potential for application to tomato germplasm resources for precisely increasing drought tolerance. However, many secondary metabolites are involved downstream of phenylpropanoid biosynthesis and may more strongly affect tomato fruit quality. The mechanism by which these metabolites are regulated and the specific effects of SlGATA17 on tomato fruit quality are unclear. Here, we overexpressed SlGATA17 in the common cultivated tomato variety Alisa Craig (AC) to establish a drought-resistant improved strain, evaluated the main agronomic traits and production capacity of this strain, and comprehensively analyzed its ripe fruit quality traits. The results revealed that SlGATA17 overexpression decreased tomato plant height and stem thickness. The yield per plant and lycopene content of ripe fruit decreased, and the capacity of fruit extracts to scavenge DPPH and ABTs significantly increased. Combined transcriptomic and metabolomic analyses revealed that the main changes occurred in the phenylpropanoid biosynthesis, flavonoid biosynthesis and anthocyanin biosynthesis pathways and that the changes in these modules significantly increased the L-phenylalanine deaminase and the anthocyanin content of the improved tomato strain. These results revealed the function and major role modules of SlGATA17 in regulating tomato fruit quality and comprehensively demonstrated the practical value of applying SlGATA17 for improving tomato traits, thus laying the foundation for breeding strategies that increase tomato stress tolerance and quality.