Organogenèse induite in vitro sur des fragments de racine de Nicotiana tabacum L.

1978 ◽  
Vol 56 (19) ◽  
pp. 2370-2374 ◽  
Author(s):  
Trinh T. Hanh

Explants taken from superficial epidermic and subepidermic tissues from flowering stocks of Nicotiana tabacum can be induced to flower, produce buds, callus, or roots from a single type of cell, of subepidermic origin. Explants from neoformed roots, when cultivated on media inducing the formation of flowers (IAA 10−6 M, kinetin 10−6 M), buds (IAA 10−6 M, BA 10−5 M), callus (2,4-D 5∙10−6 M, kinetin 10−7 M), and roots (IBA 10−5 M, kinetin 10−7 M) can form buds or callus. New roots are formed when either IAA or kinetin is omitted from the flowering medium. None of the above media induced the formation of flowers from root explants.Temperatures of 22 or 24 °C and the addition of 10−6 M BA were optimal for the de novo formation of buds from root explants. [Traduit par le journal]

Plants ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 1261
Author(s):  
Robin Lardon ◽  
Danny Geelen

Plant regeneration is essential for survival upon wounding and is, hence, considered to be a strong natural selective trait. The capacity of plant tissues to regenerate in vitro, however, varies substantially between and within species and depends on the applied incubation conditions. Insight into the genetic factors underlying this variation may help to improve numerous biotechnological applications that exploit in vitro regeneration. Here, we review the state of the art on the molecular framework of de novo shoot organogenesis from root explants in Arabidopsis, which is a complex process controlled by multiple quantitative trait loci of various effect sizes. Two types of factors are distinguished that contribute to natural regenerative variation: master regulators that are conserved in all experimental systems (e.g., WUSCHEL and related homeobox genes) and conditional regulators whose relative role depends on the explant and the incubation settings. We further elaborate on epigenetic variation and protocol variables that likely contribute to differential explant responsivity within species and conclude that in vitro shoot organogenesis occurs at the intersection between (epi) genetics, endogenous hormone levels, and environmental influences.


Molecules ◽  
2018 ◽  
Vol 23 (12) ◽  
pp. 3179 ◽  
Author(s):  
Peng Zhang ◽  
Xin Li ◽  
Xiao-Long Yuan ◽  
Yong-Mei Du ◽  
Bin-Gui Wang ◽  
...  

An endophytic fungus Arthrinium arundinis TE-3 was isolated and purified from the fresh leaves of cultivated tobacco (Nicotiana tabacum L.). Chemical investigation on this fungal strain afforded three new prenylated diphenyl ethers (1−3) as well as three known analogues (4−6). Structure elucidation of the isolated compounds was carried out by analysis of 1D and 2D nuclear magnetic resonance (NMR) and high-resolution electrospray ionization mass spectroscopy (HRESIMS) spectra, as well as by comparison of those data with literature data. The absolute configuration of the stereogenic center at C-8 in 1 was assigned by comparison of the experimental and calculated ECD spectra. Compounds 1 and 2 showed selective antifungal activity against Mucor hiemalis with minimum inhibitory concentration (MIC) values of 8 and 4 μg/mL, respectively. Compounds 5 and 6 exhibited inhibitory activity against Alteraria alternata with an MIC value of 8 μg/mL. In the cytotoxic assay, 2, 5, and 6 displayed moderate in vitro cytotoxicity against the human monocytic cell line (THP-1 cell line), with IC50 values of 40.2, 28.3, and 25.9 μM, respectively. This study indicated that endophytic fungi possess great potential for exploring new bioactive secondary metabolites.


2021 ◽  
pp. 39-43
Author(s):  
Ákos Mendel ◽  
László Kovács ◽  
Erzsébet Kiss

Polyamines, such as spermidine (Spd) spermine (Spm) and their direct precursor, the diamine putrescine (Put) are vital and essential aliphatic amines which are also present in plants. Although ethylene and polyamines are also involved in fruit ripening, the genes coding them must also take part in other biosynthetic pathways. In the ethylene and polyamines play an important role in development of salt stress tolerance, and in responses for biotic and abiotic stresses. Exogenous application of all three main polyamines (Put, Spd, Spm) increase salt tolerance of plants, but, accordingly to previous experiments, spermidine has the main effect on the enhancement of salt tolerance. Nicotiana tabacum L. plants were grown in vitro on MS medium, the treatments were as follows: arginine (150 mg l-1), putrescine (10 mg l-1), spermidine (10 mg l-1). Proline, chlorophyll a, b and polyamine contents were measured. The obtained results show that the arginine decarboxylase and the spermidine synthase genes involved in polyamine metabolism, cannot be enhanced by exogenous addition of their precursor molecules. On the contrary, the spermine synthase gene has a positive effect to the lower-class forms of polyamines.


1960 ◽  
Vol 43 (4) ◽  
pp. 841-851 ◽  
Author(s):  
Ludwig Bergmann

The cultivation of single cells of Nicotiana tabacum L. var. "Samsun" and Phaseolus vulgaris L. var. "Early Golden Cluster" on a thin agar layer in Petri dishes is described. Under these conditions about 20 per cent of the cells divided repeatedly and established tissue clones which could be isolated and maintained as growing tissue cultures. It was possible also to follow the successive divisions of isolated cells and to observe their behavior during cytogenesis under the microscope.


2001 ◽  
Vol 13 (4) ◽  
pp. 225-229 ◽  
Author(s):  
Meng-Xiang Sun ◽  
Alessandra Moscatelli ◽  
Hong-Yuan Yang ◽  
M. Cresti

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