Flower bud and root neoformation in thin cell layers of Nicotiana tabacum var. Samsun: a statistical analysis of spatial and temporal changes in mitotic activity

1990 ◽  
Vol 68 (11) ◽  
pp. 2501-2508 ◽  
Author(s):  
G. Mersch ◽  
C. Nassogne ◽  
A. Havelange

Our aim was to analyse comparatively the spatial and temporal changes in mitotic activity in tobacco thin cell layers cultured in vitro during the expression of two organogenetic programs, namely the flower bud and root programs. These biological materials were found to be so complex and heterogeneous that we had to rely on sophisticated statistical models for the planned study. Using these models we could detect differences not only between the two programs, but also within each program between different time intervals and, in the flower bud program, between different longitudinal segments of the thin cell layers. Key words: Nicotiana tabacum, flower bud, root, statistical analysis, mitotic activity.

2007 ◽  
Vol 330 (10) ◽  
pp. 728-734 ◽  
Author(s):  
Asma Ben Ghnaya ◽  
Gilbert Charles ◽  
Annick Hourmant ◽  
Jeannette Ben Hamida ◽  
Michel Branchard

1993 ◽  
Vol 71 (3) ◽  
pp. 506-511 ◽  
Author(s):  
Alain Cousson ◽  
Kiem Tran Thanh Van

Floral and vegetative organogenesis in thin cell layers of Nicotiana tabacum cv. Samsun was studied in relation to the ionic composition of the medium. The control liquid medium was buffered to pH 5.5. NH4+, NO3−, K+, and Ca2+ were separately varied between 0 or 0.1 times and 2, 3 or 4 times their initial control concentration. Increasing the concentrations of NO3−, and Ca2+ above their control concentration promoted the formation of vegetative buds instead of flowers. When K+ at 80.0 mM, Na+ at 78.9 mM, and NH4+ as the sole nitrogen source used, neither flower formation nor morphogenesis were observed in 70, 100, and 100% of the explants, respectively. NH4+ as the sole nitrogen source acidified the medium to pH 4.2, whereas the other ionic conditions did not change the external pH. NO3− at 7.9 mM prevented this acidification and allowed flower formation in 75% of the explants. This acidification could increase the K+ and Na+ influxes via a possible lowering of the intracellular pH. This hypothesis corroborates the morphogenic effect of K+ and Na+. Key words: absence of morphogenesis, acidification of medium, floral and vegetative organogenesis, ionic composition of the medium, thin cell layers, Nicotiana tabacum cv. Samsun.


Plant Science ◽  
1996 ◽  
Vol 113 (2) ◽  
pp. 167-174 ◽  
Author(s):  
Hideo Tanaka ◽  
Chikara Masuta ◽  
Jiro Kataoka ◽  
Shigeru Kuwata ◽  
Akira Koiwai ◽  
...  

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