Identification and tissue-specific expression of rutin biosynthetic pathway genes in Capparis spinosa elicited with salicylic acid and methyl jasmonate.

Capparis spinosa is an edible medicinal plant which is considered as an excellent source of rutin. Rutin is a glycoside of the flavonoid quercetin that has been reported to have a beneficial role in controlling various diseases such as hypertension, arteriosclerosis, diabetes, and obesity. In this study, the partial cDNA of four genes involved in the rutin biosynthetic pathway including 4-coumaroyl CoA ligase (4CL), flavonoid 3'-hydroxylase (F3'H), flavonol synthase (FLS) and flavonol-3-O-glucoside L-rhamnosyltransferase (RT) were identified in C.spinosa plants for the first time. The protein sequences of these genes shared high similarity with the same proteins in other plant species. Subsequently, the expression patterns of these genes as well as rutin accumulation in C.spinosa leaves treated with different concentrations of salicylic acid (SA) and methyl jasmonate (MeJA) and also in different tissues of Caper plants treated with 100 mgL-1 SA and 150 µM MeJA were evaluated. The expression of all four genes was clearly up-regulated and rutin contents increased in response to MeJA and SA treatments after 24 h. The highest rutin contents (5.30 mgg-1 DW and 13.27 mgg-1 DW), as well as the highest expression levels of all four genes, were obtained using 100 mgL-1 SA and 150 µM MeJA, respectively. Among the different tissues, the highest rutin content was observed in young leaves treated with 150 µM MeJA, which corresponded to the expression of related genes, especially RT, as a key gene in the rutin biosynthetic pathway. These results suggest that rutin content in various tissues of C. spinosa can be enhanced to a significant extent by MeJA and SA treatments and the gene expression patterns of rutin-biosynthesis-related genes are regulated by these elicitors.

Preculturing effect of thidiazuron on in vitro shoot multiplication and micropropagation round in Capparis decidua (Forsk.) an important multipurpose plant.

An efficient protocol was developed for clonal multiplication of an important shrub: Capparis decidua (Forsk.) Edgew, through in vitro shoot induction and multiplication from nodal explants. Pretreatment of nodal explants in a liquid Murashige and Skoog (MS) medium augmented with various thidiazuron (TDZ) concentrations at relatively high levels (5-100 µM) for different time duration (4, 8, 12 and 16 d), proved a significant approach for in vitro shoot production. After an initial exposure time to TDZ, nodal explants were inoculated onto a MS basal medium devoid of TDZ for further induction and proliferation. The highest regeneration rate (85%), average number of shoots/explant (8.7 ± 0.22) and maximum shoot length (3.9 ± 0.33 cm) were obtained from the nodal explants exposed to 50 µM TDZ for 8 d. The nodal explants excised from the proliferated cultures of TDZ (50 µM) for 8 d were used as explants and showed an enhancement rate after next three round of in vitro propagation. Best results for rooting was obtained by ex vitro treatment of shoots with 200 µM indole-3-butyric acid (IBA) for 20 min. as it produced an average of 5.7 ± 0.41 roots per microshoot with 4.4 ± 0.39 cm root length in 84% shoots. Different planting substrates was tested for maximum survival of hardening off micropropagated plantlets and soilrite proved most effective than others as 97.1 ± 7.21 plantlets survived. All micropropagated plants grew well in natural conditions and showed similar morphology to the mother plant.