In planta expression of specific single chain fragment antibody (scFv) against nucleocapsid protein of fig mosaic virus (FMV)

Fig mosaic virus (FMV) is recognized as the main viral agent associated with the mosaic disease (MD) of fig trees (Ficus carica). Due to its worldwide occurrence, FMV represents the most significant global threat to the production of fig fruit. A disease management strategy against the MD in fig orchards has never been effective; and therefore, expression of recombinant antibody in plant cells could provide an alternative approach to suppress FMV infections. In this study we focused on expressing a specific recombinant antibody, a single-chain variable fragment (scFv), targeting the nucleocapsid protein (NP) of FMV in planta. To accomplish this objective, we inserted the scFv gene into a plant expression vector and conducted transient expression in leaves of Nicotiana tabacum cv. Samson plants. The construct was transiently expressed in tobacco plants by agroinfiltration, and antibody of the anticipated size was detected by immunoblotting. The produced plantibody was then assessed for specificity using ELISA and confirmed by Western blot analysis. In this study, the plantibody developed against FMV could be considered as a potential countermeasure to the infection by conferring resistance to MD.

Improvement of phytochemical and quality characteristics of Dracocephalum kotschyi by drying methods

This experiment was conducted to evaluate the effects of different drying methods on drying parameters and qualitative characteristics of Dracocephalum kotschyi in a completely randomized design with three replications. Treatments included shade drying as control, sun drying, cabinet drying (CD at 50 and 60°C), refractance window drying (RWD), infrared drying (IRD) at 200 and 300 W, and combination of RWD+ IRD at 200 and 300 W. According to the results, IRD, RWD, and RWD+ IRD effectively maintained valuable secondary metabolites compared to the conventional drying methods. The maximum total phenol content (2.7 and 2.66 mg GAE/g dry weight), total flavonoid content (2.26 and 2.33 mg QE/g dry weight), antioxidant activity (79% and 78.33%), and essential oil content (0.65% and 0.76%) were obtained from plants dried by RWD and IRD. Samples dried by RWD, IRD, and RWD+ IRD had high color quality, acceptable green color, and less browning. Also, RWD and IRD methods effectively reduced microbial contamination of dried plants compared to the control and other methods. The minimum aerobic mesophiles, mold, yeast, and coliforms were observed at 3.11, 0, and 1.47 log CFU/g in IRD 300 W and 3.17, 1, and 1.30 log CFU/g in RWD. D. kotschyi dried at CD 50°C had the maximum microbial contamination. Generally, according to the obtained results, RWD and IRD methods are suggested for drying of D. kotschyi and similar herbs due to shortening the drying time, preserving and improving the quality properties of dried plants.

Establishment and characterization of a Satureja khuzistanica Jamzad (Lamiaceae) cell suspension culture: a new in vitro source of rosmarinic acid

An in vitro approach to the production of rosmarinic acid (RA), a medicinally important caffeic acid ester, in a cell suspension culture (CSC) of Satureja khuzistanica Jamzad (Lamiaceae) has been investigated for the first time. The CSC was established from friable calli derived from shoot tip explants in Gamborg's B5 liquid medium supplemented with 30 g/L sucrose, 20 mg/L L-glutamine, 200 mg/L casein hydrolysate, 5 mg/L benzyladenine (BA) and 1 mg/L indole-3-butyric acid (IBA). The effect of nitrogen source (KNO3 and (NH4)2SO4) and their different concentrations on the fresh and dry weight (g/L), as well as RA content (mg/g dry weight) were measured. CSC growth measurements indicated a maximum specific cell growth rate of 1.5/day, a doubling time of 7.6 days and a high percentage of cell viability (96.4 %) throughout the growth cycle. Maximum cell fresh weight (353.5 g/L), dry weight (19.7 g/L) and RA production (180.0 mg/g) were attained at day 21 of culture. Cell growth and RA content were affected by nitrogen deficiency. Media containing 8.3 mM of total nitrogen (¼ of B5 standard medium) led to a minimum cell fresh weight (243.0 g/L), dry weight (17.4 g/L) and RA content (38.0 mg/g) after 21 days. The established CSC provided useful material for further optimization experiments aimed at a large-scale production of RA.

In-vitro Callus Induction and Rosmarinic Acid Quantification in Callus Culture of Satureja khuzistanica Jamzad (Lamiaceae)

In the present study, an efficient protocol has been developed for callus induction and production of RA in callus culture of Satureja khuzistanica for the first time. In-vitro callus induction was achieved from young shoot tip explants cultured on MS and B5 media supplemented with different concentrations of IBA (0.1, 1.0, 2.0 and 5.0 mgL(-1)) solely or in combination with cytokinins BAP and KIN (1.0, 2.0 and 5.0 mgL(-1)). B5 medium supplemented with 1.0 mgL(-1) IBA plus 5.0 mgL(-1) BAP and MS medium fortified with 2.0 mgL(-1) IBA and 2.0 mgL(-1) BAP were the most favorable media for callus formation with the highest induction rate (96%). Maximum growth index (2.89 and 2.63) and maximum callus biomass (2.34 and 2.33 g fresh weight) were obtained from the callus cultured on B5 medium supplemented with 1.0 mgL(-1) IBA plus 5.0 mgL(-1) BAP and MS medium fortified with 1.0 mgL(-1) IBA plus 1.0 mgL(-1) KIN, respectively. Determination and quantification of RA in cultured calli were performed by HPLC UV/MS analysis. Calli induced from the plant and maintained on supplements of IBA and BAP in the absence of light produced RA 7.5% based on dry weight (DW). No differentiation was observed in any callus during the course of this study.