摘要 :
The effect of plant growth regulators, nutrient strength of MS medium, sucrose concentration. and photosynthetic photon flux (PPF) on the induction and proliferation of embryogenic callus (EC) in Pimpinella brachycarpa was investi...
展开
The effect of plant growth regulators, nutrient strength of MS medium, sucrose concentration. and photosynthetic photon flux (PPF) on the induction and proliferation of embryogenic callus (EC) in Pimpinella brachycarpa was investigated. The optimal MS medium strength and Sucrose concentration for induction and proliferation of EC were 1.0X and 30 g.L-1, respectively. Treatment with 2,4-D resulted in more induction of both EC and non-embryogenic callus (NEC) than other plant growth regulators. The percentage of EC induction was the greatest (40%) after treatment with 2.0 mg.L-1 2,4-D. Treatment with NAA, IAA, and IBA resulted in rooting and/or shooting, which is disadvantageous for establishing a micropropagation system using somatic embryogenesis. EC proliferation rate was the greatest in auxin-free medium. Better EC induction was found in darkness or dim fighting (20 mu mol.m(-2).s(-1) PPF) compared to higher PPFs. EC proliferation was also retarded at higher PPFs and was best at 0 mu mol.m(-2).s(-1) PPF. After inducing EC from a single explant, the EC mass increased 25 times (from 0.05 to 1.30 g) after 4 weeks when nutritional, chemical and physical factors were optimized.
收起
摘要 :
Among the alternative plant sources of camptothecin (CPT), Nothapodytes nimmoniana is regarded as the most convenient source for large-scale isolation of the monoterpenoid indole anticancer alkaloid. As a result, CPT annual trade ...
展开
Among the alternative plant sources of camptothecin (CPT), Nothapodytes nimmoniana is regarded as the most convenient source for large-scale isolation of the monoterpenoid indole anticancer alkaloid. As a result, CPT annual trade value has grossed over billion US Dollars in recent years. Somatic embryogenesis (SE) offers potential application in the rapid clonal propagation of the tree and production of the alkaloid, so as to mitigate indiscriminate harvest of its endangered natural population to meet industrial demand. However, response to the production of embryogenic callus (EC) in the in vitro cultures of N. nimmoniana is poor to scant. In the present study, two-dimensional electrophoresis (2-DE) and mass spectrometry (MaSp/MaSp) were employed in studying proteome expression changes between EC and non-embryogenic callus (NEC) of the forest tree. The results of the study showed higher metabolic and physiological processes associated with embryogenic competence acquisition in the callus cultures; high cellular oxidative stress, energy metabolism, protein synthesis, and other metabolic processes played a key role in upregulated expression of the identified proteins in EC over NEC. Putative role of the expressed proteins during embryogenic competence acquisition by N. nimmoniana callus cultures has provided some insight into the physiology of the competence acquisition through cellular roles played by oxidative stress and metabolic processes. Further studies on metabolic physiological processes associated with EC production could have application in optimizing culture conditions for mass propagation through the SE, so as to mitigate the indiscriminate harvest of endangered N. Nimmoniana natural population for CPT.
收起
摘要 :
It is well established that the accumulation of storage products is a reliable marker for the classification of embryogenic cells. The present study characterizes embryogenic and non-embryogenic calli of Hevea brasiliensis through...
展开
It is well established that the accumulation of storage products is a reliable marker for the classification of embryogenic cells. The present study characterizes embryogenic and non-embryogenic calli of Hevea brasiliensis through histochemical localization of storage reserves. Inoculation of immature anthers on callus induction medium induced type I (soft and watery) and type II (semifriable / compact) callus. Observations showed that embryogenic callus consists of small cells with prominent nuclei, while non embryogenic calli were characterized by large cells having prominent nuclei. Histochemical examination revealed the accumulation of significant amount of storage starch, lipids and proteins which were dispersed throughout the cells of embryogenic calli, particularly, at later stage than in early phase, whereas low level accumulation of major storage reserves was detected in non-embryogenic calli.
收起
摘要 :
An investigation was conducted to study the effects of explant sources, plant growth regulators, carbohydrates and light conditions on indirect cormlet regeneration and the induction of embryogenic callus of freesia (Freesia x hyb...
展开
An investigation was conducted to study the effects of explant sources, plant growth regulators, carbohydrates and light conditions on indirect cormlet regeneration and the induction of embryogenic callus of freesia (Freesia x hybrida Bailey 'Argenta'). Sections of two different types of explants, corms and pupae (cold storage-produced corms), were placed on Murashige and Skoog (MS) media containing different concentrations of plant growth regulators. The results showed that the highest percentage ofcallus induction (100%), the highest callus growth (15 mm diameter) and the best type of calli were achieved for pupa explants grown on the medium that contained 4 mg L~(-1) 1-naphthaleneacetic acid (NAA) and 2 mg L~(-1) 6-benzylaminopurine (BAP) in thedark. Increasing BAP up to 3 to 4.5 mg L~(-1) resulted in the maximum number of regenerated cormlets from 1 cm2 calli (2 cormlets) under light conditions. Overall, the best rooting of regenerated cormlets was achieved on MS media supplemented with 1 mgL~(-1) indole-3-butyric acid (IBA). In the next stage, high quality calli were subcultured on MS media containing sorbitol, sucrose, maltose and mannitol (0, 5, 10 and 15 g L~(-1). The results indicated that 15 g L_I maltose was able to induce the highest percentage of embryogenic callus, with an average of 88.9% on media containing 2 mg L~(-1) BAP and 1 mg L~(-1) NAA.
收起
摘要 :
In order to optimize tissue culture conditions for genetic transformation of zoysiagrass (Zoysia japonica Stued.), the effect of plant growth regulators and culture medium supplements on embryogenic callus induction from mature se...
展开
In order to optimize tissue culture conditions for genetic transformation of zoysiagrass (Zoysia japonica Stued.), the effect of plant growth regulators and culture medium supplements on embryogenic callus induction from mature seeds of a cultivar 'Zenith' were investigated. The optimal concentration and treatment period of NaOCl is 30% (v/v) for 60 minutes. Cultivation of mature seed on the callus induction medium containing 3 mg/L 2,4-D and 3 mg/L dicamba showed 17.5% of embryogenic callus formation frequency. Supplementation of 1 g/L casein hydrolysate and 500 mg/L L-proline improved frequency of embryogenic callus induction. Addition of the medium with 5 mg/L AgNO_3 and 20 mg/L cysteine enhanced frequencies of embryogenic callus induction. Efficient callus induction system established in this study will be useful for molecular breeding of zoysiagrass through genetic transformation.
收起
摘要 :
In order to optimize tissue culture conditions for genetic transformation of zoysiagrass (Zoysia japonica Stued.), the effect of plant growth regulators and culture medium supplements on embryogenic callus induction from mature se...
展开
In order to optimize tissue culture conditions for genetic transformation of zoysiagrass (Zoysia japonica Stued.), the effect of plant growth regulators and culture medium supplements on embryogenic callus induction from mature seeds of a cultivar 'Zenith' were investigated. The optimal concentration and treatment period of NaOCl is 30% (v/v) for 60 minutes. Cultivation of mature seed on the callus induction medium containing 3 mg/L 2,4-D and 3 mg/L dicamba showed 17.5% of embryogenic callus formation frequency. Supplementation of 1 g/L casein hydrolysate and 500 mg/L L-proline improved frequency of embryogenic callus induction. Addition of the medium with 5 mg/L AgNO_3 and 20 mg/L cysteine enhanced frequencies of embryogenic callus induction. Efficient callus induction system established in this study will be useful for molecular breeding of zoysiagrass through genetic transformation.
收起
摘要 :
The number of protocorm-like bodies (PLBs) and embryogenic callus formed in hybrid Cymbidium Twilight Moon 'Day Light' is affected by the culture vessel (CV) used. Borosilicate test tubes (CV1), plastic and glass Petri dishes (CV2...
展开
The number of protocorm-like bodies (PLBs) and embryogenic callus formed in hybrid Cymbidium Twilight Moon 'Day Light' is affected by the culture vessel (CV) used. Borosilicate test tubes (CV1), plastic and glass Petri dishes (CV2 and CV3), Whatman filter paper No. 1 membrane rafts (CV4), Milliseal~R-covered jam jars (CV5), the Vitron~(TM) (CV6) and 100-ml glass Erlenmeyer flasks (CV7, control) were tested. CVT7, which is the vessel conventionally used for the sub-culture and micropropagation of Cymbidium PLBs, resulted in 15.6 ± 1.15 PLBs per CV. CV2 and CV3 were as effective as CV7 (14.9 ± 0.95 and 15.8 ± 1.07, respectively) in PLB proliferation. Even though PLBs that formed in CV4 had higher fresh and dry weights, much fewer PLBs per CV were formed. In general, aerated CVs (CV5 and CV6) resulted in greater responsiveness of PLBs to callus formation, but differences were not significant. Although some laboratories have their established protocols for PLB proliferation, tests on the use of different CVs should be conducted prior to mass propagation since the choice of CV can affect material and running costs, the ease of multiplication and the quantitative output.
收起
摘要 :
The gelling agent and a selection of alternative medium additives impacted the number of protocorm-like bodies (PLBs) and percentage callus formed in hybrid Cymbidium Twilight Moon 'Day Light'. Gellan gum resulted in greater PLB p...
展开
The gelling agent and a selection of alternative medium additives impacted the number of protocorm-like bodies (PLBs) and percentage callus formed in hybrid Cymbidium Twilight Moon 'Day Light'. Gellan gum resulted in greater PLB production and callusformation than all other gelling agents tested which included agar, Bacto agar, phytagel, oatmeal agar, potato dextrose agar, guar gum, isubgol and com starch. All of the alternative medium additives (full fat milk, Coca-cola~R, coffee, green and Darjeeling teas) negatively impacted PLB production and almost completely suppressed callus formation, although tissue browning appeared to have been reduced by the presence of teas and coffee.
收起
摘要 :
The expression pattern of the LEC2 gene during somatic embryogenesis (SE) in Arabidopsis explants (immature zygotic embryos) induced in vitro was followed, using real-time quantitative PCR (qRT-PCR). The analysis revealed differen...
展开
The expression pattern of the LEC2 gene during somatic embryogenesis (SE) in Arabidopsis explants (immature zygotic embryos) induced in vitro was followed, using real-time quantitative PCR (qRT-PCR). The analysis revealed differential expression of LEC2 transcripts within a 30 days time course of somatic embryo development. A significant auxin-dependent upregulation of the LEC2 gene was found to be associated with the induction phase of SE. In contrast to embryogenic culture the level of LEC2 expression was noticeably lower in non-embryogenic callus of Col-0 and hormonal mutants (cbp20 and axr4-1) with low SE-efficiency. The study with 35S::LEC2-GR transgenic plants showed that overexpression of LEC2 can compensate for the auxin requirement, and that transgenic explants formed somatic embryos when cultured in vitro under auxin-free conditions. However, unlike in auxin-induced SE, intense callus formation preceded the embryogenic response triggered via LEC2 overexpression, suggesting an indirect pathway of morphogenesis. Moreover, a negative interaction between auxin treatment and LEC2 overexpression in terms of SE efficiency was observed, as transgenic explants cultured on auxin medium displayed a significantly reduced level of embryogenic potential. The study provides further experimental evidence that in the determination of the embryogenic response in Arabidopsis somatic cells, a close link exists between auxin and the LEC2 activity.
收起
原文获取