The Impact of Growing Area on the Expression of Fruit Traits Related to Sensory Perception in Two Tomato Cultivars

Abstract

Environmental conditions greatly influence the quality of tomato fruit by affecting the expression of genes, the abundance of metabolites, and the perception of sensorial attributes. In this study, a fruit transcriptome investigation, a sensory test, and a metabolomic analysis were performed to evaluate the impact of the environment on two popular tomato cultivars grown in two Italian regions. The transcriptional profile of each cultivar, cultivated in two different areas, highlighted differential expression in genes involved in pathways related to cell wall components such as pectin, lignin, and hemicellulose and sugars as well as in amino acids, phenylpropanoids, and pigment synthesis. The cultivation area mainly affects sensory attributes related to texture and flavor and the metabolic pattern of cell wall precursors, sugars, glutamate, aspartate, and carotenoids. In the two genotypes cultivated in the same environment, some attributes and fruit-related quality processes are similarly affected, while others are differently influenced based on the specific genetic makeup of the tomato. A combination of transcriptomic, sensory, and metabolomic data obtained from the two tomato genotypes revealed that the environment has a profound effect on specific sensory traits, providing information on factors that shape the specific characteristics and genetic targets for improving tomato fruit characteristics.

Keywords: Solanum lycopersicum; environment; fruit quality; metabolite; sensory attributes; transcriptome.

Figure 1

(A) Differentially expressed genes (DEGs) identified in two tomato genotypes (Dardo and Pixel) cultivated in two environments. Ba = Battipaglia, Fo = Fondi. (B) Intersection of differentially expressed genes. Rows indicate each dataset. Pi = Pixel, Da = Dardo, up = up-regulated, down = down-regulated. Blue filled circle indicates DEG sets participating in the intersection. Vertical bar plots indicate the size of the intersection in terms of the number of DEGs.

Figure 2

MapMan metabolism overview showing differences in transcript levels between the two environments in Dardo (A) and Pixel (B). Green squares represent up-regulated transcripts and red squares represent down-regulated transcripts.

Figure 3

Pixel and Dardo DEGs involved in carbohydrate metabolisms, focusing on cell wall precursors biosynthesis for pectin, hemicellulose, and cellulose. Red boxes indicate down-regulated genes and green boxes indicate up-regulated genes. Da = Dardo, Pi = Pixel.

Figure 4

Dardo and Pixel DEGs involved in lignin pathway in tomatoes. Red boxes indicate down-regulated genes, green boxes indicate up-regulated genes. Da = Dardo. Pi = Pixel.

Figure 5

Dardo and Pixel DEGs involved in carotenoid synthesis. Red boxes indicate down-regulated genes, green boxes indicate up-regulated genes. Da = Dardo, Pi = Pixel.

Figure 6

Sensory differences between tomato samples cultivated in Battipaglia and Fondi (A) Pixel; (B) Dardo.

Figure 7

Principal component analysis showing the separation of metabolic profiles for each genotype between the two environments.