Aliphatic glucosinolate synthesis and gene expression changes in gamma-irradiated cabbage

Area of Science:

• Plant biochemistry
• Food science
• Molecular biology

Background:

• Glucosinolates are key compounds in Brassicales plants, influencing flavor and health benefits.
• Post-harvest processing, including ionizing radiation, can alter glucosinolate levels in vegetables.
• Gamma irradiation is explored for food security and safety, with prior reports noting increased sinigrin in irradiated cabbage.

Purpose of the Study:

• To investigate the molecular basis of radiation-induced changes in glucosinolate content in cabbage.
• To analyze the expression of specific genes involved in glucosinolate biosynthesis following gamma irradiation.

Main Methods:

• Quantitative RT-PCR was used to analyze the expression of seven glucosinolate biosynthetic pathway genes (MYB28, CYP79F1, CYP83A1, SUR1, UGT74B1, SOT18, TGG1).
• Jasmonate content was measured to assess its role in radiation-induced glucosinolate changes.

Main Results:

• Gamma irradiation led to the up-regulation of several glucosinolate biosynthetic genes, including CYP83A1, MYB28, UGT74B1, CYP79F1, and SUR1.
• Jasmonate levels remained unaffected in irradiated cabbage, indicating they are not involved in this radiation-induced effect.
• This study provides the first report on gamma irradiation's impact on glucosinolate biosynthetic gene expression in vegetables.

Conclusions:

• Gamma irradiation modulates glucosinolate biosynthesis in cabbage at the gene expression level.
• The observed increase in sinigrin is likely mediated by the up-regulation of specific biosynthetic genes, independent of jasmonate signaling.
• Findings contribute to understanding the molecular effects of irradiation on vegetable composition and quality.