جستجوی مقالات مرتبط با کلیدواژه "ریشه ای مویین" در نشریات گروه "کشاورزی"

Galega (Galega officinalis L.) from the leguminous family is used to treat diabetes. Hairy root culture is a valuable system for the production of secondary metabolites on a large scale. The use of elicitors in plant tissue and cell culture is one of the most efficient biotechnological tools for inducing biosynthesis and accumulation of secondary metabolites. This study aimed to investigate the effect of iron, silver, and silicon nanoparticles on growth and galegine content in hairy roots of G. officinalis.

In this study, induction of hairy roots in leaf, cotyledon, and hypocotyl explants of G. officinalis was performed using the A4 strain of Rhizobium rhizogenes, and the effect of different concentrations of silver, silicon, and iron oxide nano-elicitors on growth and galegine, phenol, and flavonoids content of hairy roots was investigated.

The highest rate of root induction was obtained in leaf explants with an average of 5 roots per explant. The highest root growth rate belonged to the treatments with 50 and 100 mg l-1 silicon nanoparticles for 72 h. Application of all levels of silver, iron, and silicon elicitors for 36 h resulted in a significant increase in the total phenol content of hairy roots. Thus that the highest amount of total phenol was obtained in 36 h treatment of roots with a concentration of 100 mg l-1 of silicon nanoparticles without significant difference with 10 and 20 mg l-1 silver nanoparticles. Also, the highest amount of total flavonoids was obtained at 200 mg l-1 iron nanoparticles for 36 h; and the highest content of galegine was obtained in the treatment of roots with 10 and 20 mg l-1 silver, and 100 mg l-1 silicon nanoparticles for 36 h.

The appropriate type and concentration of elicitors is an effective factor in the response of hairy roots to nano-elicitors. The highest yield of galegine (17.55 mg) was obtained in the treatment of roots with 50 mg l-1 of silicon nanoparticles for 72 h. This can be attributed to both better growth of hairy roots and high galegine content at this treatment.

Transformed hairy roots obtained by infection of plants with Agrobacterium rhizogenes strains are used as a tissue culture tool for secondary metabolite production since hairy roots are genetically and biologically stable and they are able to produce metabolite within a short time. Chicory (Cichorium intybus L.) is a medicinal plant from Asteraceae. This plant contains many important metabolites include chicoric asid, inulin, scoline, coumarin and flavonoids.

The seeds were surface-sterilized by rinsing with 2% benomil for 30 min and later sterilized with 5% sodium hypochlorite for 20 min and subsequently with 70% ethanol for 90 s. the wounded leaf of 20 and 28-day-old seedlings inoculated with Agrobacterium rhizogenes 11325. Bacterial colonies were cultured on liquid LB medium for 1 day. The explants were submerged in the solution for 15 min and were shaken gently. After that, the explants were drained on sterile filter paper and then transferred to MS solid medium. The explants were incubated at (25 ± 2) ◦C under dark condition for three different co-cultivation period (24, 48 and 72 hours). In the next step, the explants were transferred to MS solid medium supplemented with 500 mg/L cefotaxime. The explants were incubated at (25 ± 2) ◦C under a 16-h photoperiod condition for four weeks. At the end of incubation time, the percentage of hairy root induction, root number and root length were investigated. Genomic DNA of Cichorium intybus L. hairy root was extracted following the method of CTAB and subjected to PCR analysis. Non-transformed root DNA was used as a negative control and pRi11325 plasmid DNA was used as positive control. The pair of primers specific to the rolB fragment sequences was: 5-ATGGATCCCAAATTGCTATTCCCCACGA -3 and 5-TAGGCTTCTTTCATTCGGTTTACTGCAGC-3. The amplification protocol for the rolB was a 5 min melting at 94 ◦C followed by 35 cycles of a 5 min melting at 94 ◦C, a 45 s annealing at 55 ◦C and a 1 min elongation at 72 ◦C, and final elongation at 72 ◦C for 7 min. PCR products were electrophoretically separated on 0.8 % agarose gels (w/v) and stained with gel red. To determine the best media composition for growth of hairy roots, approximately 100 mg FW roots were cultured in basal liquid MS, solid MS and liquid 1/2MS medium supplemented with 500 mg/L cefotaxime on a rotary shaker (90 rpm) at 25 ◦C in dark for 5 weeks, and increase in fresh weight and dry weight was recorded at 5 week later. Three replicates were made for each experimental set. Non-transformed roots were cultured on same mediums.

Each of the two different explants – leaf and petiole showed different levels of hairy root induction in different co-culture time. Hairy root induction was observed 7 days after co-cultivation. There were low adventitious roots formed from control explants. 72 hours co-cultivation period was found to be more efficient in inducing hairy root phenotype in both explant types. The infection of explants by A. rhizogenes is a process that implies a succession of events, including the transfer and integration of T-DNA, into the host plant genome. Therefore, the time of contact between A. rhizogenes and the explants determines the transformation efficiency. A maximum of transformation frequency (53.33%) was observed in leaf explants in 72 hours co-cultivation followed by 33.33% in petiole explants in 72 hours co-cultivation. In leaf explants maximum root number (8.5 roots per explant) and maximum length of root (9.16 cm) induced from 20-day-old seedling in 72 hours co-culture. In petiole explants maximum root number (3.66 roots per explant) and maximum root length (11.46 cm) induced from 28-day-old seedling in 72 hours co-culture. The “hairy root” phenotype characterized by high branching and fast growth was previously reported in “reactive species” like Datura innoxia but not for “difficult species”. The high phenolic content of woody plant species could be responsible for the reduced hairy root phenotype as reported for gingko or pine. Three different culture media (solid MS, liquid MS and 1/2 MS media) were tested to determine the best suitable media for the maximum Biomass of hairy roots line.

Genetically transformed hairy roots obtained by infection of plants with Agrobacterium rhizogenes are suitable source for production of bioactive molecules due to their genetic stability and generally show fast growth in culture media free of growth hormones. This study describes the protocol for hairy root induction which could further be useful for the production of secondary metabolites and biomass.

Induced hairy roots by Agrobacterium rhizogenes are a suitable tissue for the production of secondary metabolites, due to the stability and high production of roots in hormonal-free conditions. Trigonella foenum – graecum L. is one of the medical plants in the family Fabaceae. Many useful components in Trigonella foenum L. leafs are Calcium, Iron, Phosphorus, Carotene, Ascorbic acid, Protein, Thiamine, Riboflavin. Also, this plant widely used as anti-diabetes, blood glucose, cholesterol- lowering, Anti-cancer, Antibacterial, and food stuffing. In this study, hairy roots were induced using A. rhizogenes strains A4, ATCC11325 and ATCC15834 by injection method in complete seedling, cotyledon and hypocotyl explants. The effect of strain type and explant type, were investigated on the effectiveness of hairy roots. The explants were cultured in B5 medium with 4 replications. Hairy roots appeared in bacterial inoculation after 2 to 3 weeks. The highest amount of transgenic (93%), hairy roots number (10.43 number) and the maximum root length (6.64 cm) were observed in complete seedling explant of 10 days and A4 strain. In the hypocotyl explants, the hairy roots were not observed.

Hairy roots culture is a potential system for secondary metabolite production in medicinal plants. In this research, hairy root induction in Echinacea angustifolia was established using Agrobacterium rhizogenes. The effects of different A. rhizogenes strains (AR15834, A4, K599 and MSU440) in two solid growth regulator- free culture media, half strength MS salts with B5 vitamins and WPM, were evaluated on hairy root induction in 60-day-old explants. The highest percentage of root induction was obtained by AR15834 strain in the WPM medium (46.6%). Also, the effects of age (20, 40 and 60 day-old) and type (leaf, leaf lamina and petiole) of explant on hairyroot induction were investigated by AR15834 strain in the WPM medium. The high frequency of hairy root induction was obtained in leaf explants (52.4%) and 40 day-old leaf explants (62.3%).Transgenic hairy roots were confirmed by PCR analysis with specific primers of rolB gene.

In this research, after optimization of sterilizing cyst and larvae of second stage of Heterodera schachtii, the possibility of using nematode on seedlings of sugar beet (Beta vulgaris L.) in in vitro condition was studied for developing larvae to cyst. For this purpose, non sterile cysts were extracted from infected soil and hatched into zinc chloride solution with concentration of 0.5gl-1. Then, for preparation of sterile second stage larvae, several sterilizing treatments were used . Mean comparisons were performed between sterilized live larvae number by Duncan's method. Results showed that 70% ethanol for 1 minute followed by 5% sodium hypochlorite for 5 minutes and 0.1% sodium hypochlorite for 20 minutes were the best treatments for disinfecting cysts and larvae, respectively. In the next step, two nematode susceptible sugar beet varieties were applied to produce cyst from the larvae in in vitro culture. PGoB medium containing different hormonal compositions was used to produce hairy roots and inoculation of seedling with sterilized larvae. After nematode inoculation tests, were the stained cysts were observed under stereomicroscope and counted 40 days later. Five to twelve cysts were formed on the roots of each seedling from two varieties. As a result, it seems that this technique can be used for sugar beet germplasm evaluation to screen nematode resistant genotypes in in vitro controlled condition.