Genetic Modification of Wetland Grasses for Phytoremediation

2005 ◽  
Vol 60 (3-4) ◽  
pp. 285-291 ◽  
Author(s):  
Mihály Czakó ◽  
Xianzhong Feng ◽  
Yuke He ◽  
Dali Liang ◽  
László Márton

Abstract Wetland grasses and grass-like monocots are very important natural remediators of pollutants. Their genetic improvement is an important task because introduction of key transgenes can dramatically improve their remediation potential. Tissue culture is prerequisite for genetic manipulation, and methods are reported here for in vitro culture and micropropagation of a number of wetland plants of various ecological requirements such as salt marsh, brackish water, riverbanks, and various zones of lakes and ponds, and bogs. The monocots represent numerous genera in various families such as Poaceae, Cyperaceae, Juncaceae, and Typhaceae. The reported species are in various stages of micropropagation and Arundo donax is scaled for mass propagation for selecting elite lines for pytoremediation. Transfer of key genes for mercury phytoremediation into the salt marsh cordgrass (Spartina alterniflora) is also reported here. All but one transgenic lines contained both the organomercurial lyase (merB) and mercuric reductase (merA) sequences showing that co-introduction into Spartina of two genes from separate Agrobacterium strains is possible.

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Anthony J. Conner ◽  
Helen Searle ◽  
Jeanne M. E. Jacobs

Abstract Background A frequent problem associated with the tissue culture of Compositae species such as chicory (Cichorium intybus L.) and lettuce (Lactuca sativa L.) is the premature bolting to in vitro flowering of regenerated plants. Plants exhibiting such phase changes have poor survival and poor seed set upon transfer from tissue culture to greenhouse conditions. This can result in the loss of valuable plant lines following applications of cell and tissue culture for genetic manipulation. Results This study demonstrates that chicory and lettuce plants exhibiting stable in vitro flowering can be rejuvenated by a further cycle of adventitious shoot regeneration from cauline leaves. The resulting rejuvenated plants exhibit substantially improved performance following transfer to greenhouse conditions, with increased frequency of plant survival, a doubling of the frequency of plants that flowered, and substantially increased seed production. Conclusion As soon as in vitro flowering is observed in unique highly-valued chicory and lettuce lines, a further cycle of adventitious shoot regeneration from cauline leaves should be implemented to induce rejuvenation. This re-establishes a juvenile phase accompanied by in vitro rosette formation, resulting in substantially improved survival, flowering and seed set in a greenhouse, thereby ensuring the recovery of future generations from lines genetically manipulated in cell and tissue culture.


2009 ◽  
Vol 3 (2) ◽  
pp. 99-106
Author(s):  
A.A. Al-jibouri ◽  
A.A. Al-salhay

The aim of this investigation was produced micro tubers of four potato cultivars Premiere, Bintje, Estima and Escort in vitro. Apical meristems (0.2-0.4 mm) of potato cultivars were excised and cultured on nutrient medium and incubated at 24±2 Cº and 1000 lux light intensity for 16 hrs per day. The developing plantlets were examined serological by using ELISA technique to eliminate the viral infected plantlets. The virus-free plantlets were chopped into pieces with single bud and re cultured on fresh medium for mass propagation. For micro tubers formation in test tubes, the cultures were transferred to another medium containing a high percent of sucrose (60g/L) with different concentrations of kinetin; the cultures were incubated under 16±2 Cº and 8 hrs photoperiod. The plantlets formed micro tubers after 8-10 weeks from culturing. The results showed significant differences among cultivar’s in their response to in vitro culture and micro tubers formation. The results also showed that the kinetin concentration had significant effect on micro tubers, and 1mg/l kinetin concentration was the best. The micro tubers were stored for 10 week at 4Cº to break down the dormancy period, and gave 100% germination under nursery condition. Numbers of tubers derived from micro tubers and normal tubers of these cultivars were compared at the end of season.


2021 ◽  
Vol 31 (1) ◽  
pp. 51-60
Author(s):  
RI Oyediran ◽  
JO Afolabi ◽  
DB Olomola ◽  
FO Akanni

Nauclea diderrichii is a tree species of economic importance. However, its plantation establishment is limited by inadequate seedling production. Hence, there is ample scope of tissue culture for its mass propagation. Its in vitro plantlets development as affected by media strengths indicated that 100 % seed germination was obtained in full MS basal medium while the least (3.35 %) was from quarter-strength at 8 Weeks after inoculation (WAI). The effects of BAP and NAA assessed on the growth of its sub-cultured plantlets showed that highest number of leaves (17) and adventitious shoots (3) were obtained from MS basal medium supplemented with 0.1 mg/l BAP only. Whereas, highest shoot length (3.61 cm) and average number of roots (5/plantlet) were obtained from the same medium without hormone(s) at 8 WAI. Further sub-culturing into MS with 0.05 mg/l NAA resulted into plantlets having optimum shoot and massive root growth ready for acclimatization in 6 WAI. The plantlets were successfully acclimatized using coconuthusk/ topsoil mixture with 90 % survival. Plant Tissue Cult. & Biotech. 31(1): 51-60, 2021 (June)


1970 ◽  
Vol 45 (1) ◽  
pp. 75-78 ◽  
Author(s):  
Shahina Islam ◽  
Mosfequa Zahan ◽  
Shahina Akter ◽  
Tanjina Akhtar Banu ◽  
Ahashan Habib ◽  
...  

An efficient mass propagation method for Feronia limonia was developed from excised shoot tips and nodal explants of in vitro grown seedlings. Explants were cultured on MS medium with different conc. of NAA, Kn, IAA and BAP singly or in combinations. Highest number of micro shoots and better plant growth were obtained from these two explants on MS medium supplemented with 0.2 mg/l BAP alone. The regenerated shoots were successfully rooted on MS medium supplemented with 0.5 mg/l NAA. The in vitro raised plantlets were successfully established in soil following the formation of roots with 100% survivability under ex vitro condition. Key words: Feronia limonia; Mass propagation; Node; Shoot tips; Multiple shoot DOI: 10.3329/bjsir.v45i1.5186 Bangladesh J. Sci. Ind. Res. 45(1), 75-78, 2010


2007 ◽  
Vol 87 (4) ◽  
pp. 911-922 ◽  
Author(s):  
Samir C Debnath

Vacinium fruits are genetically heterozygous species characterized as “not coming true from seed”. Conventional methods for vegetative propagation of these species, although successful, are slow and labour-intensive, and few propagules can be produced from one plant of a selected clone or hybrid. Micropropagation techniques are important for clonal multiplication, germplasm im provement and gene conservation of Vaccinium fruits cultivated in Canada including blueberries, cranberries and lingonberries. In vitro propagation of these species using axillary bud proliferation and adventitious shoot regeneration has been investigated in a number of studies. Morphogenesis seems to be highly dependent on plant growth regulators and media used for culture, and this dependence is genotype specific. The paper presents the progress in-depth of various aspects of the in vitro culture of Canadian Vaccinium species for their commercial production. Also discussed are techniques for clone rejuvenation and plant tissue culture for mass propagation of Canadian Vaccinium nuclear stocks. Key words: Blueberry, cranberry, lingonberry, micropropagation, regeneration, morphology


2019 ◽  
Vol 46 (1) ◽  
pp. 22-31 ◽  
Author(s):  
Youn Hee Kim ◽  
Gee Young Lee ◽  
Hye Hyeong Kim ◽  
Jae Hong Lee ◽  
Jae Hong Jung ◽  
...  

Blood ◽  
2008 ◽  
Vol 111 (7) ◽  
pp. 3591-3598 ◽  
Author(s):  
Xavier Cullere ◽  
Michael Lauterbach ◽  
Naotake Tsuboi ◽  
Tanya N. Mayadas

Abstract Tissue-specific silencing of genes may be used for genetic engineering in mice and has possible therapeutic applications in humans. Current strategies in mice rely on Cre/loxP technology requiring the generation of multiple transgenic lines and breeding strategies. Here, we describe the selective silencing of CD18, a leukocyte-specific integrin in neutrophils using a micro RNA (miRNA) strategy that requires the generation of one transgenic line. CD18-specific miRNA hairpin driven by the myeloid specific human MRP8 promoter resulted in the generation of transgenic lines with 75% to 95% reduction in CD18 protein levels in neutrophils and monocytes. Minimal decreases in T cells and a partial diminution in macrophages were observed. Neutrophil CD18 silencing resulted in neutrophilia, splenomegaly, and significant defects in neutrophil trafficking with the degree of alterations correlating with the extent of CD18 silencing. Thus, our data demonstrate the utility of using miRNA approaches to silence genes in neutrophils, which are terminally differentiated cells with a short half-life that largely precludes their genetic manipulation in vitro. Furthermore, the mouse models provide a valuable tool to examine the contribution of CD18 on neutrophils to leukocyte adhesion deficiency type I (LAD-I), a complex inherited disorder in which reduced or absent CD18 expression in multiple leukocyte subsets leads to impaired innate and adaptive immune responses.


2011 ◽  
Vol 29 (3) ◽  
pp. 359-363 ◽  
Author(s):  
Jean C Cardoso ◽  
Elizabeth O Ono

One of the most important applications of plant tissue culture is mass propagation of ornamental plants. This experiment evaluated the effect of different concentrations of NH4NO3 and KNO3 and BAP on the in vitro growth of orchid hybrid Brassocattleya 'Pastoral'. Seedlings of this orchid hybrid were used as explants and cultivated in medium with mineral salts and vitamins from the MS medium (Murashige & Skoog, 1962), with the macronutrients P, Ca and Mg reduced by half, and with an addition of 25 g L-1 of sucrose, 0.1 g L-1 of myo-inositol and 1.5 g L-1 of activated charcoal. Agar-agar was added (6.5 g L-1) and the pH was adjusted to 5.8. As treatments, four concentrations of the NH4NO3 and KNO3 (2x; 1x; ½ and ¼ MS medium) and three concentrations of BAP (0.0; 0.5 and 1.0 mg L-1) were assayed. The multiplication, growth in height, fresh and dry weight and sugar level in dry weight of sprouts were evaluated. There occurred a higher growth in height with 0.25x NH4NO3 and KNO3 salts concentrations of MS medium and higher rate of multiplication with combination of NH4NO3 and KNO3 reduced by half of the MS medium concentration and 1.0 mg L-1 BAP.


1998 ◽  
Vol 88 (5) ◽  
pp. 437-441 ◽  
Author(s):  
P. Russo ◽  
S. A. Slack

Following regeneration, putative virus-resistant transgenic plants are usually transferred from tissue culture to a greenhouse or growth chamber to screen for resistance to infection and disease development using mechanical, graft, or insect vector inoculation methods. To reduce initial screening costs and time, we developed mechanical and graft inoculation methods suitable for tissue culture use. The in vitro methods were validated by comparing them with similar greenhouse screens using putative potato virus Y strain o (PVY°) replicase-mediated resistant regenerants of the potato cultivar Atlantic. Five transgenic lines were tested, with similar results obtained from in vitro and greenhouse experiments. Two of the transgenic lines, A1 and A3, showed the greatest resistance to PVY°infection, as indicated by low enzyme-linked immunosorbent assay values and infection rates. In vitro mechanical inoculation methods were also used to infect wild-type tomato and tobacco plants with cucumber mosaic virus and potato virus Y. Potato plants were also infected with the phloem-restricted potato leafroll virus, a low-titer virus, using in vitro graft inoculation methods. These results suggest the potential usefulness of these simple, effective, and economical techniques for screening large numbers of putative virus-resistant plants.


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