Correlation of Ascorbic Acid Content and the Pattern of Monodehydroascorbate Reductases (MDHARs) Gene Expression in Leek (Allium porrum L.)

In this study, the content of ascorbic acid and the expression pattern of MDHAR1, MDHAR4, and MDHAR5 monodehydroascorbate reductase genes were determined in various parts of leek plants (Allium porrum L.), which were collected as they grow (in July and October). In the leaves of all analyzed cultivars, the ascorbate content was higher than in the pseudo-stem (2.3-3.7 times in July and 2.1-4.1 times in October). MDHAR transcripts were found in all analyzed parts of leeks. Leaves and pseudo-stems were characterized by high levels of expression of all three MDHAR genes. A similar transcription level was observed in July and October for the MDHAR5 gene in all parts of the plant. Two different patterns of gene expression, depending on the collection time point, for the MDHAR4 gene were observed. It was found that the analyzed leek cultivars exhibit similar MDHAR1 and MDHAR4 expression dynamics during the formation of the pseudo-stem. At the same time, the MDHAR4 transcription level positively correlates with the content of ascorbic acid in the white part and green leaves of leek plants.