Biosynthesis of rutin changes in Capparis spinosa due to altered expression of its pathway genes under elicitors' supplementation

Caper plant is (Capparis spinosa L.) a good source of rutin which plays a key role in the human diet. In this study, the effect of different concentrations of salicylic acid (SA) and methyl jasmonate (MeJA) on the weight of anther-derived calli and their rutin contents were assessed in caper plants. Also, we investigated the rutin content and expression pattern of some rutin related genes in leaves of caper plants at vegetative and fresh fruiting growth stages under SA and MeJA treatments. In the first experiment, the highest rutin contents were observed in anther-derived calli treated with 10 mu M MeJA and 100 mg L-1 SA after 2 weeks from initial treatments, which were 2.44 and 2.22-fold higher than control. Also, the treatment of caper plants with150 mu M MeJA and 100 mg L-1 SA resulted in a higher increase in the rutin content of leaves at the fresh fruiting stage (61.46 and 9.99 mg g(-1) DW, respectively), in the second experiment. Among the studied genes, the FLS gene showed the highest expression in the leaves of the MeJA- and SA-treated plants at vegetative growth stage, while in the fresh fruiting stage the highest expression was related to the RT gene. Use of 150 mu M MeJA and 100 mg L-1 SA enhanced the expression levels of the RT gene up to 7.36 and 2.89 times of the control, respectively. These results suggest that rutin content and the expression patterns of rutin biosynthesis genes in caper can be significantly enhanced by the SA and MeJA treatments in a growth stage-dependent manner. Key message Methyl jasmonate and salicylic acid treatments enhance the rutin contents of Capparis spinosa in vitro and in vivo and up-regulate the rutin biosynthetic related genes at two different growth stages.