Stem cell induction and plant regeneration are affected by medium components in maca (Lepidium meyenii Walp).

BACKGROUND: In medicinal plants, selection, reproduction and preservation of important genotypes are very necessary. Nowadays, using tissue culture and regeneration techniques of medicinal plants under in vitro conditions has been able to proliferate medicinal plants widely, which is much higher than traditional methods of vegetative propagation. Maca (Lepidium meyenii), is an industrial plant whose root is the usable part. Maca has valuable medicinal effects such as sexual enhancement and reproductive power, infertility treatment, improved sperm count and quality, anti-stress, osteoporosis prevention and more. METHODS AND RESULTS: This study was conducted to induce callus and regeneration of Maca. First, MS medium supplemented with different concentrations of Kinetin, Naphthaleneacetic acid and 2,4-Dichlorophenoxyacetic acid [0.5, 1 and 2 µM respectively] and control were compared for callus induction from root and leaves. After 38 days of incubation, the first callus appeared, after 50 days of callus induction and after 79 days regeneration occurred. The callus induction experiment was performed for the study of the effect of three explants (leaf, stem and root) and seven hormone levels. The regeneration experiment was carried out by studying the effect of three explants (leaf, stem and root) on eight levels of the hormone. The results of data analysis on callus induction showed that the effects of explants, hormones and their interactions on callus induction percentage were highly significant but not significant on callus growth rate. The results of regression analysis showed that explants, hormones and their interactions had no significant effect on regeneration percentage. CONCLUSION: Based on our results, the best medium for inducing callus was Hormone 2,4-D [2 µM] and Kinetin [0.5 µM], in which the highest percentage of callus induction was in leaf explants (62%). And the lowest were in stem (30%) and root (27%) explants. According to the comparison of the mean, the best environment for regeneration of the environment was 4 µM 6-Benzylaminopurine 2.5 + Thidiazuron, in which the highest percentage of regeneration was in leaf explant (87%) and stem (69%) and the lowest in root explant (12). %).

Evaluation of the expression of induced genes in response to dehydration stress of Camelina (Camelina sativa) calli.

Plants are constantly exposed to various biological and non-biological stresses that endanger their lives. Drought stress is one of the abiotic stresses that have a great impact on the yield and life of plants and is one of the main causes of reduced crop yields. Reducing the effects of environmental stresses such as drought using methods such as irrigation, fertilizer application and appropriate planting methods is limited. Therefore, genetic modification of plants is an important effort to minimize the effect of environmental stresses. in this research, Twenty disinfected camelina seeds were cultured on the MS medium containing 3% sucrose, 0.8% agar and pH 5.8 under a laminar hood. After 14 days, the cotyledon explants (about 1 cm) were separated from the seedlings and placed on the callus induction medium. The MS callus induction medium containing 0.5 mg / l kinetin, 2 mg / l -2,4 D, 3% sucrose, 0.8% agar and pH 5.8. Samples were subcultured every two weeks to the same medium and calli were formed after 4 weeks. Then the calli were transferred to the medium containing a concentration of 30% PEG. To study gene expression, first callus samples were treated with liquid nitrogen and to study the effect of drought stress on gene expression, this sample was sent to Zagros Bioidea Company located in the Razi University Incubator. Gene expression was performed through microarray technology. The results showed that seven different genes whose expression increased by almost six times the control value can be mentioned, including Cold-acclimation protein (CAP160), NAC10, Abscisic acid (ABA), ABF4, CRK3, lysM domain receptor-like kinases (LYKs) and Basic/helix-loop-helix(bHLH130-like). Drought tolerance is not a genetically simple trait, but a quantitative and complex trait with various aspects that require the use of molecular methods to investigate the relevant mechanisms. This study aimed to investigate the expression of different genes of callus tissues of the Camelina plant under stress and non-stress conditions by microarray method.