The effects of S-metolachlor on some fatty acids and fatty acids gene expressions in safflower (Carthamus tinctorius L.)

Safflower (Carthamus tinctorius (L.)) is one of the widely studied plants due to its resistance to abiotic stress, suitability for summer and winter cultivation, rich in nutrients and linoleic acid. Thus, it has become more important compared to other oil plants in recent years. Weed infestation affects the growth of this cultivated plant during the greening period. S-metolachlor is one of the widely used herbicides that prevent the growth of weeds. In this study, three different doses of S-metolachlor (1, 2 and 4 g of active substance/L) were applied to two different safflower genotypes (Dinçer and Remzibey-05), and their effects were assessed in oleic acid and linoleic acid contents. A decrease in Remzibey-05 genotype's oleic acid content was observed with all doses of herbicide. On the other hand, for the Dinçer genotype, only the dose with 1 g active substance/L caused a decrease. Linoleic acid content increased in both genotypes. In the early growing period of safflower genotypes, the expression level of some fatty acid desaturase genes (CtFAD2-1, CtFAD3, CtFAD6 and CtFAD7) were used to investigate the proportions and conversion of fatty acids (CtFAD2-1, CtFAD3, CtFAD6 and CtFAD7). The expression of CtFAD2-1 and CtFAD6 genes, which are responsible for the conversion of oleic acid to linoleic acid, is generally reduced compared to the control. A decrease was observed in the expression of CtFAD3 and CtFAD7 genes, which are responsible for the conversion of linoleic acid to linolenic acid.