Dear Javier Raya Gonzalez

Pls. find the attached files

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3809525/

http://scialert.net/fulltext/?doi=biotech.2007.561.566

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3146736/

https://www.researchgate.net/publication/45947441_Callus_Induction_and_in_vitro_Complete_Plant_Regeneration_of_Different_Cultivars_of_Tobacco_Nicotiana_tabacum_L_on_Media_of_Different_Hormonal_Concentrations

https://www.researchgate.net/profile/Gowher_Ali/publication/45947441_Callus_Induction_and_in_vitro_Complete_Plant_Regeneration_of_Different_Cultivars_of_Tobacco_Nicotiana_tabacum_L_on_Media_of_Different_Hormonal_Concentrations/links/0fcfd50ffc270d2e72000000.pdf?origin=publication_list

http://www.cell.com/trends/plant-science/pdf/S1360-1385(97)84623-7.pdf

http://ijpbs.net/issue-3/29.pdf

Hoping this will be helpful

Regards

Prof. Houda Kawas

Article Callus Induction and in vitro Complete Plant Regeneration of...

Also

Hello Javier Raya Gonzalez, 

As suggested by Houda Kawas madam a number of research papers are there. Did you performed any preliminary tissue culture work with these tobacco explants?   And if yes then, on the basis of those results and available research  papers published earlier you may find out what will be the best proportion of auxin: cytokinin in medium for callus induction.

wish you good luck Gonzalez.

At least in Nicotiana benthamiana and Nicotiana sylvestris that we are frequently working with, callus formation is very easy in hormone media and seems to be the default process. The challenge actually is to prevent callus formation during transformation because you can directly induce organogenesis in transformed leaves without the need to go to callus and embryo formation since this shortens the time very significantly. To induce plantlets on tobacco leaf explants without significant callus formation, we use a 10 fold more cytokinin than auxin on the initial medium. Specifically, 50 μl BAP (1 mg/ml)  and 5 μl NAA (1 mg/ml) in 100 ml media will give you organs more or less escaping the callus phase in just about 3 weeks or so. But if you are interested in making callus, just use equal concentrations of auxin and cytokinin. Especially if you use 2,4-D in place of NAA, even half the amount of BAP promotes massive callus formation and it takes much longer time to regenerate plants.

Good luck!

As noted by others, plenty of possibilities out there. We use the following in two possibilities in a laboratory for students (all concentrations are final):

Both, basic medium: MS salts, Gamborg vitamins, 0.7% agar, 3% sucrose.

Hormones, possibility A (some callus, some regeneration of roots and shoots): NAA 1mg/l, BAP 0.5mg/l.

Possibility B (lots of callus, no regeneration as the auxin in non-transportable): 2,4-D 1 mg/l, BAP 0.5mg/l

Best of luck!

Hi Javier, the above suggestion will work. But if you are planning to use MS basal medium with tobacco callus, invest some time and take a look at the original Murashige and Skoog publication. 

Back to the roots!

http://onlinelibrary.wiley.com/doi/10.1111/j.1399-3054.1962.tb08052.x/abstract

http://priede.bf.lu.lv/grozs/AuguFiziologijas/Augu_audu_kulturas_MAG/literatura/03_Murashige%20Scoog1962.pdf

Good luck!