Evaluation of Solasonine Content and Expression Patterns of SGT1 Gene in Different Tissues of Two Iranian Eggplant (Solanum melongena L.) Genotypes

Mahmoud Bagheri1,2*small orcid_display_4pp, Ali Akbar Shahnejat Bushehri1*small orcid_display_4ppMohammad Reza Hassandokht3small orcid_display_4pp and Mohammad Reza Naghavi1small orcid_display_4pp

1Department of Agronomy and Plant Breeding, College of Agriculture and Natural Resources, University of Tehran, Chamran Blvd., IR-31587- 77871 Karaj, Iran
2Seed and Plant Improvement Institute, Agricultural Research, Education and Extension Organization (AREEO), Fahmideh Blvd., IR-31585-4119 Karaj, Iran
3Department of Horticultural Sciences, College of Agriculture and Natural Resources, University of Tehran, Chamran Blvd., IR-31587-77871 Karaj, Iran

Article history:
Received July 10, 2016
Accepted February 15, 2017

Key words:
eggplant, gene expression, glycoalkaloids, SGT1 gene

Eggplant (Solanum melongena L.) is one of the most consumed vegetables in the world. The eggplant glycoalkaloids (GAs) are toxic secondary metabolites that may have detrimental effects on human health, particularly if the magnitudes of GAs are higher than the recommended food safety level (200 mg per kg of fresh mass). In this study, the content of solasonine compound and the expression patterns of solasodine galactosyltransferase (SGT1) gene were assessed in different tissues (mature leaves, flower buds, young, mature, and physiologically ripe fruits) of two Iranian eggplant genotypes (D1 and J10) under field conditions. The maximum mass fraction of solasonine in D1 was detected in flower buds (135.63 µg/g), followed by leaf (113.29 µg/g), physiologically ripe fruit (74.74 µg/g), young fruit (61.33 µg/g), and mature fruit (21.55 µg/g). Comparing both genotypes, the genotype of bitter fruits (J10) contained higher mass fraction of solasonine, as one of the main factors for producing bitter flavour of the plant. Regarding the expression profiles of SGT1, in both genotypes, the activity of the gene was increased nearly parallel with the concentration of solasonine. In the J10 genotype, transcript level of the gene was significantly higher than the genotype of sweet fruits (D1). Although both D1 and J10 genotypes are possibly recommendable for human food consumption, D1 is more suitable for daily diet.

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