scholarly journals Silicon Promotes Adventitious Shoot Regeneration and Enhances Salinity Tolerance ofAjuga multifloraBunge by Altering Activity of Antioxidant Enzyme

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Iyyakkannu Sivanesan ◽  
Byoung Ryong Jeong

We investigated the effect of Si concentration on shoot regeneration and salinity tolerance ofAjuga multiflora. Addition of Si to the shoot induction medium significantly increased the frequency of shoot induction. The average number of shoots regenerated per explant decreased on the medium containing NaCl alone, while there was less decrease when the shoot induction medium was supplemented with both NaCl and Si. The shoot induction percentage increased linearly with increasing concentration of Si in the NaCl containing medium. Addition of Si to the shoot induction medium significantly increased SOD, POD, APX, and CAT activity in regenerated shoot buds as compared with the control. The inclusion of Si to the NaCl containing medium significantly increased the SOD activity in leaves and roots, while it decreased POD, APX, and CAT activity in both organs. Scanning electron microscopic analysis showed that there are no distinct differences in the structure of stomata between the control and Si-treated plants. However, NaCl treatment significantly affected the structure and number of stomata as compared to the control. Wavelength dispersive X-ray analysis confirmed the high Si deposition in trichomes of plants grown in the Si containing medium but not in plants grown in the medium without Si.

2021 ◽  
Author(s):  
Jorge Fonseca Miguel

The response on callus and shoot formation under different light incubation conditions was evaluated in cucumber (Cucumis sativus L.). Four-day-old cotyledon explants from the inbred line 'Wisconsin 2843' and the commercial cultivars 'Marketer' and 'Negrito' were employed. A four-week culture was conducted on MS-derived shoot induction medium containing 0.5 mg L-1 IAA and 2.5 mg L-1 BAP, under an 8-h dark/ 16-h light regime, or by a one- or two-week dark pre-incubation followed by the same photoperiod. Significant differences were obtained for the regeneration of shoots in all cultivars. The response in both frequency and number of shoots under continuous photoperiod was at least 3-6 fold higher than with dark pre-incubation. The highest genotypes response was obtained by 'Negrito' and 'Marketer' with identical values. All explants formed callus, and in two of the three cultivars, the response on callus extension was not significantly affected by incubation conditions. The results clearly show that shoot induction under continuous photoperiod regime was beneficial for adventitious shoot regeneration in cucumber.


1982 ◽  
Vol 60 (12) ◽  
pp. 2729-2733 ◽  
Author(s):  
Edward G. Kirby ◽  
Margaretha E. Schalk

Cotyledons of Douglas-fir are triangular in cross section and possess two epistomatic surfaces with centrally located stomatal rows (commonly seven). After 1 week in culture on a medium inducing adventitious shoot formation (5 μM N6-benzylaminopurine and 5 μM α-naphthalene acetic acid (NAA)) or callus proliferation (5 μM NAA) cells of the hypodermal region immediately below the epidermis begin to elongate and divide rupturing the epidermis. Apical domes of adventitiously produced bud primordia emerge from the ruptured epidermis after 14–21 days in culture on shoot induction medium. Emergence of buds takes place preferentially on epistomatic cotyledonary surfaces. The large number of hypodermal cells that respond to shoot induction medium by forming adventitious shoots suggests further investigation of fundamental events associated with morphogenesis in cotyledon cultures of Douglas-fir.


HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 461d-461
Author(s):  
Richard L. Bell ◽  
Ralph Scorza ◽  
Chinnathambi Srinivasan

An efficient regeneration/transformation system was developed for `Beurre Bosc' pear. Young leaves were harvested from in vitro shoots proliferated on a medium containing MS basal salts and 5 BAP, 0.5 μM IBA, and 0.6M3. Shoot regeneration was optimized using a modification of the medium of Chevreau and Leblay (1993). Explants were cultured on shoot induction medium contained 10 μM TDZ and 1 μM IBA for 4 weeks in the dark, and then transfered to a similar, but auxinless, regeneration medium until shoots developed, usually after an additional 4 to 8 weeks. Leaf tissues were transformed by co-cultivation for 3 days with Agrobacterium tumefaciens EHA101 carrying a pGA482 plasmid containing NPTII, GUS, and rolC genes, followed by cultivation on SIM containing 300 mg/L timentin. Putative transgenic plants were selected on shoot induction medium containing 80mg/L kanamycin, and multiplied on shoot proliferation medium. Four clones were confirmed as transgenic using the GUS histochemical assay and Southern blots for the NPTII and rolC genes. Plants of each clone have been rooted and successfully transfered to the greenhouse for further analysis of gene expression.


Coatings ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 861
Author(s):  
Minako Kubo ◽  
Minako Tachiki ◽  
Terumasa Mitogawa ◽  
Kota Saito ◽  
Ryota Saito ◽  
...  

Solution-cast coating films of perchlorate-doped oligo(3-methoxythiophene) exhibited a gold-like luster similar to that of metallic gold despite the involvement of no metals. However, the development mechanism of the luster remains ambiguous. To understand the mechanism, we performed scanning electron microscopic analysis, variable-angle spectral reflectance measurements, and ellipsometry measurements on ClO4−-doped oligo(3-methoxythiophene) cast film with a gold-like luster. The results revealed that the lustrous color of the film was not induced by the submicron-sized regular structures (structural color), nor by the high-density free electrons (reflective response based on Drude model), but by the large optical constants (refractive index and extinction coefficient) of the film, as speculated previously.


1986 ◽  
Vol 64 (11) ◽  
pp. 2467-2479 ◽  
Author(s):  
William G. Young ◽  
Therese M. Marty

A group of wild moose from Manitoba, Canada, were documented as having excessive tooth wear. Replicas of one incisor tooth were collected from 16 individuals and from 19 controls for comparison by volumetric and scanning electron microscopic analysis. All animals were aged from tooth cementum lines. Tooth replicas were cast from silicone rubber impressions in epoxy resin and sputter coated with gold. Tooth wear with age was compared statistically by measuring crown height, percent tooth loss, interfacet distance, and facet area on the incisors. The unique pattern of wear on the anterior teeth of affected moose was described. In affected animals, crown heights were significantly reduced and percent tooth loss was excessive. Microwear analysis found that an abrasive agent, acting predominantly in a lingual to labial direction, had been responsible for loss of enamel and dentine incisally and interproximally, and on the facial and lingual surfaces to a lesser extent. Interdental facets became involved by vertical abrasion. Control teeth showed fewer but coarser scratches and only approached the pattern of wear found in affected moose in a few individuals in old age. The loss of tooth structure would lead to diminished cropping efficiency and damage to the periodontium.


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