scholarly journals Organogenesis and Sonication-Assisted Agrobacterium-Mediated Transformation of Poplar Roots

Author(s):  
Thais Salete Giovanella ◽  
Juliana Degenhardt ◽  
Laudiane Bruna Zanella ◽  
João Carlos Bespalhok Filho

Abstract Functional genomics along with genetic transformation and plant regeneration are used to identify genes of interest, comprising essential tools to obtain plants with desired characteristics. In this study, we described an organogenesis and a genetic transformation protocol for Populus tremula x Populus alba clone 717-1B4 using roots. In the organogenesis experiments the PGRs zeatin, BA and kinetin at different concentrations were evaluated. The effect of explant age was evaluated and at 30 days “old” roots (6 months old) showed a higher regeneration rate when compared to “young” roots (2 months old). In the genetic transformation experiments kanamycin concentration, the use of sonication (SAAT), co-cultivation period and explant age were evaluated. Sonication positively affected transformation, while co-cultivation time did not interfere. Regarding explant age, no statistical differences were observed. Quantitative real-time PCR (qPCR) data showed that among the six transgenic plants evaluated, two presented two copies and the others only one copy of the gene. In this study, efficient protocols of organogenesis and genetic transformation for poplar roots are presented with a transformation efficiency of 58%.

Agronomy ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1104
Author(s):  
Ritika Bhatt ◽  
Prem Prakash Asopa ◽  
Rohit Jain ◽  
Aditi Kothari-Chajer ◽  
SL Kothari ◽  
...  

An efficient and reproducible protocol for Agrobacterium tumefaciens mediated genetic transformation was developed for kodo millet (Paspalum scrobiculatum L.) by optimizing various parameters. Agrobacterium strains EHA 105 and LBA 4404 harboring plasmids pCNL 56 and pCAMBIA 2300, respectively, provided the highest transformation efficiency. Addition of acetosyringone (AS) in infection medium (200 µM EHA 105, 250 µM–LBA 4404) and co-cultivation medium (50 µM) increased the transformation efficiency. Transient and stable expression of gus gene was confirmed with histochemical assay of infected embryos and leaves of transformed plants, respectively. The best GUS response was obtained by pretreatment of callus with an antinecrotic mixture (10 mg/L Cys + 5 mg/L Ag + 2.5 mg/L As) at infection time of 20 min followed by co-cultivation for 3 days (EHA 105) and 5 days (LBA 4404) in dark. Regenerated transgenic plants were obtained after 8 to 10 weeks of selection on callus induction medium (NAA 0.5 mg/L, BAP 1 mg/L) containing 50 mg/L Kan + 250 mg/L Cef and were rooted for 2 weeks on MS medium containing PAA (1 mg/L) and phytagel. The plantlets established in greenhouse showed normal growth. Therefore, the protocol developed in the present study can be used for development of improved varieties of kodo millet.


Genes ◽  
2020 ◽  
Vol 11 (8) ◽  
pp. 860
Author(s):  
Saba Haider ◽  
Yaohui Gao ◽  
Yike Gao

Chrysanthemum (Chrysanthemum x morifolium Ramat.) cultivar Jinba is a distinctive short-day chrysanthemum that can be exploited as a model organism for studying the molecular mechanism of flowering. The commercial value of Jinba can be increased in global flower markets by developing its proper regeneration and genetic transformation system. By addressing typical problems associated with Agrobacterium-mediated transformation in chrysanthemum, that is, low transformation efficiency and high cultivar specificity, we designed an efficient, stable transformation system. Here, we identify the features that significantly affect the genetic transformation of Jinba and standardize its transformation protocol by using CmTFL1a as a transgene. The appropriate concentrations of various antibiotics (kanamycin, meropenem and carbenicillin) and growth regulators (6-BA, 2,4-D and NAA) for the genetic transformation were determined to check their effects on in vitro plant regeneration from leaf segments of Jinba; thus, the transformation protocol was standardized through Agrobacterium tumefaciens (EHA105). In addition, the presence of the transgene and its stable expression in CmTFL1a transgenic plants were confirmed by polymerase chain reaction (PCR) analysis. The CmTFL1a transgene constitutively expressed in the transgenic plants was highly expressed in shoot apices as compared to stem and leaves. Overexpression of CmTFL1a led to a delay in transition to the reproductive phase and significantly affected plant morphology. This study will help to understand the biological phenomenon of TFL1 homolog in chrysanthemum. Moreover, our findings can explore innovative possibilities for genetic engineering and breeding of other chrysanthemum cultivars.


HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 572d-572
Author(s):  
Hak-Tae Lim ◽  
Haeng-Soon Lee ◽  
Tage Eriksson

Plant regeneration of ginseng has been known to be difficult, and there are a few reports on plant regeneration of ginseng via somatic embryogenesis. In vitro flowering has, however, been one of the major drawbacks in these regeneration systems in which BA and GA3 were included in germination and shoot multiplication media. Multiplication of adventitious shoots from a single somatic embryo, abnormal morphology, and vitrified shoots were also observed. All these facts have made successful acclimatization of ginseng plantlets difficult. The purposes of this study were 1) to establish the plant regeneration system via organogenesis, 2) to improve normal plant regeneration via somatic embryogenesis, 3) to improve the efficiency of plant regeneration from protoplast culture, 4) to understand the acclimatization process, 5) to develop effective genetic transformation protocol. Data in relation with all these studies are presented in detail.


2011 ◽  
Vol 5 (S7) ◽  
Author(s):  
Raj Deepika ◽  
Adri Veale ◽  
Cathleen Ma ◽  
Steven H Strauss ◽  
Alexander A Myburg

2016 ◽  
Vol 25 (2) ◽  
pp. 155-164 ◽  
Author(s):  
Shruti Bardar ◽  
SL Kothari ◽  
Sumita Kachhwaha

An efficient and reproducible protocol for in vitro plant regeneration and Agrobacterium-mediated genetic transformation was developed for Eclipta alba (L.) Hassk. using nodal explants. Several parameters affecting Agrobacteriummediated gene delivery were investigated and optimized. These include antibiotic concentration, preculture period, infection time, use of acetosyringone, co-cultivation period and temperature and increased level of copper in induction, co-cultivation and regeneration medium. Incorporation of elevated level of CuSO4 led to significant improvements in plant regeneration and recovery of transformed plants. The highest frequency of transformation was observed when explants were infected and co-cultivated at 23oC. Higher transformation frequency was attained by augmenting the medium with 1.0 ?M CuSO4 which was ten times the normal MS level. Addition of acetosyringone in the infection and co-cultivation media was very beneficial and resulted in greater transformation efficiency. Transient and stable expression of gus gene was confirmed with histochemical assay of infected explants and leaves of regenerated transformants, respectively. Molecular analysis of transformed plants with nptII and gus A specific primers revealed the amplification of nptII and gus gene thereby demonstrated the efficacy of optimized protocol for A. tumefaciens-mediated genetic transformation in Eclipta alba for the first time.Plant Tissue Cult. & Biotech. 25(2): 155-164, 2015 (December)


2019 ◽  
Vol 46 (3) ◽  
pp. 223-230
Author(s):  
Atmitri Sisharmini ◽  
Bambang Sapta Purwoko ◽  
Nurul Khumaida ◽  
Dan Kurniawan Rudi Trijatmiko

Protocols for genetic transformation of rice have been widely developed, however the protocols are not universal and inapplicable for all types of rice plants directly. Transformation protocol on rice cv. Fatmawati needs to be developed to generate transgenic lines. The present research was carried out to optimize genetic transformation protocol in rice cv. Fatmawati mediated by Agrobacterium tumefaciens harboring pCambia1301 construct using immature embryo as an explant. The experiment was arranged in a completely randomized design. Factors influencing efficiency of transformation, i.e., sensitivity of callus to hygromycin antibiotic, acetosyringone concentration used in cultivation medium, hygromycin concentration for transformant selection were optimized. The results showed that genetic transformation of rice cv. Fatmawati mediated by A. tumefaciens using immature embryos have been successfully carried out with several parameters. Addition of 100 µM acetosyringone in co-cultivation medium and 30 mg L-1 hygromycin for transformant callus selection were optimal for genetic transformation of rice cv. Fatmawati mediated by A. tumefaciens. Transformation efficiency was found to be 7.84% based on the lines carrying the hpt gene. This result would be a valuable reference in genetic transformation of rice cv. Fatmawati using target genes.Keywords: immature embryo, Oryza sativa, pCambia1301, transformation efficiency


Author(s):  
Masoumeh Nomani ◽  
Masoud Tohidfar

Abstract Background Trachyspermum ammi is one of the key medicinal plant species with many beneficial properties. Thymol is the most important substance in the essential oil of this plant. Thymol is a natural monoterpene phenol with high anti-microbial, anti-bacterial, and anti-oxidant properties. Thymol in the latest research has a significant impact on slowing the progression of cancer cells in human. In this research, embryos were employed as convenient explants for the fast and effectual regeneration and transformation of T. ammi. To regenerate this plant, Murashige and Skoog (MS) and Gamborg's B5 (B5) media were supplemented with diverse concentrations of plant growth regulators, such as 6-benzyladenine (BA), 1-naphthaleneacetic acid (NAA), 2,4-dichlorophenoxyacetic acid (2,4-D), and kinetin (kin). Transgenic Trachyspermum ammi plants were also obtained using Agrobacterium-mediated transformation and zygotic embryos explants. Moreover, two Agrobacterium tumefaciens strains (EHA101 and LBA4404) harboring pBI121-TPS2 were utilized for genetic transformation to Trachyspermum ammi. Results According to the obtained results, the highest plant-regeneration frequency was obtained with B5 medium supplemented with 0.5 mg/l BA and 1 mg/l NAA. The integrated gene was also approved using the PCR reaction and the Southern blot method. Results also showed that the EHA101 strain outperformed another strain in inoculation time (30 s) and co-cultivation period (1 day) (transformation efficiency 19.29%). Furthermore, HPLC method demonstrated that the transformed plants contained a higher thymol level than non-transformed plants. Conclusions In this research, a fast protocol was introduced for the regeneration and transformation of Trachyspermum ammi, using zygotic embryo explants in 25–35 days. Our findings confirmed the increase in the thymol in the aerial part of Trachyspermum ammi. We further presented an efficacious technique for enhancing thymol content in Trachyspermum ammi using Agrobacterium-mediated plant transformation system that can be beneficial in genetic transformation and other plant biotechnology techniques.


Author(s):  
Richa Bajaj ◽  
Lani M. Irvin ◽  
Brajesh Nanda Vaidya ◽  
Sadanand A. Dhekney ◽  
Nirmal Joshee

2021 ◽  
Vol 7 (2) ◽  
pp. 138
Author(s):  
Min Liang ◽  
Wei Li ◽  
Landa Qi ◽  
Guocan Chen ◽  
Lei Cai ◽  
...  

Fungi from unique environments exhibit special physiological characters and plenty of bioactive natural products. However, the recalcitrant genetics or poor transformation efficiencies prevent scientists from systematically studying molecular biological mechanisms and exploiting their metabolites. In this study, we targeted a guanophilic fungus Amphichorda guana LC5815 and developed a genetic transformation system. We firstly established an efficient protoplast preparing method by conditional optimization of sporulation and protoplast regeneration. The regeneration rate of the protoplast is up to about 34.6% with 0.8 M sucrose as the osmotic pressure stabilizer. To develop the genetic transformation, we used the polyethylene glycol-mediated protoplast transformation, and the testing gene AG04914 encoding a major facilitator superfamily transporter was deleted in strain LC5815, which proves the feasibility of this genetic manipulation system. Furthermore, a uridine/uracil auxotrophic strain was created by using a positive screening protocol with 5-fluoroorotic acid as a selective reagent. Finally, the genetic transformation system was successfully established in the guanophilic fungus strain LC5815, which lays the foundation for the molecular genetics research and will facilitate the exploitation of bioactive secondary metabolites in fungi.


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