Root apical organization in monocotyledons—Zingiberaceæ

1961 ◽  
Vol 53 (5) ◽  
pp. 240-256 ◽  
Author(s):  
S. K. Pillai ◽  
Ambuja Pillai ◽  
Susheila Sachdeva
Keyword(s):  
Apical Organization

APICAL ORGANIZATION IN ROOTS OF THE CONVOLVULACEAE

1969 ◽  
Vol 56 (2) ◽  
pp. 131-138 ◽  
Author(s):  
James L. Seago ◽  
Charles Heimsch
Keyword(s):  
Apical Organization

Effect of Picloram on Organogenesis in Detached Leaves ofEcheveria elegansBgr.

Weed Science ◽  
1976 ◽  
Vol 24 (2) ◽  
pp. 175-182 ◽  
Author(s):  
M. V. S. Raju ◽  
R. Grover
Keyword(s):  
Root Elongation ◽  
Shoot Organogenesis ◽  
Tracheary Elements ◽  
Vascular Differentiation ◽  
Root Primordia ◽  
Low Concentrations ◽  
Parenchyma Cells ◽  
Callus Production ◽  
Detached Leaves ◽  
Apical Organization

The effect of picloram (4-amino-3,5,6-trichloropicolinic acid) on regeneration of detached leaves ofEcheveria elegansBgr. was studied. Picloram stimulated callus production at all concentrations. Low concentrations of 1 to 15 ppmw picloram did not affect shoot organogenesis and the same, however, stimulated rhizogenesis. Inhibition of both root- and shoot-organogenesis was noticeable at concentrations below 20 ppmw and above. Roots increased in number at all picloram concentrations below 40 ppmw, the maximum number being at concentration of 15 to 20 ppmw of the herbicide. Observations indicated that root elongation was considerably suppressed. Picloram-induced callus contained mature parenchyma cells devoid of contents and considerable amount of tissue disruption was noticed. Irregular vascular differentiation and obliteration of tissues particularly in the region of tracheary elements, were obvious. Although normal apical organization was lacking in root primordia and in arrested short roots, these elongated normally into mature roots when they were transferred to water, thus indicating that apical meristems were not severely affected by picloram.

Choroidal readaptation to gravity in rats after spaceflight and head-down tilt

1998 ◽  
Vol 84 (1) ◽  
pp. 19-29 ◽  
Author(s):  
Julien Davet ◽  
Benoit Clavel ◽  
Lucien Datas ◽  
Laurence Mani-Ponset ◽  
Daniel Maurel ◽  
...  
Keyword(s):  
Fine Structure ◽  
Carbonic Anhydrase ◽  
Choroid Plexus ◽  
Life Sciences ◽  
National Institutes Of Health ◽  
Carbonic Anhydrase Ii ◽  
Protein Distribution ◽  
Earth Gravity ◽  
Orthostatic Position ◽  
Apical Organization

Davet, Julien, Benoit Clavel, Lucien Datas, Laurence Mani-Ponset, Daniel Maurel, Serge Herbuté, Michel Viso, William Hinds, Joellen Jarvi, and Jacqueline Gabrion.Choroidal readaptation to gravity in rats after spaceflight and head-down tilt. J. Appl. Physiol.84(1): 19–29, 1998.—To determine when choroidal structures were restored after readaptation to Earth gravity or orthostatic position, fine structure and protein distribution were studied in rat choroid plexus dissected either 6 h [Space Life Sciences-2 (SLS-2) experiments] or 2 days [National Institutes of Health-Rodent 1 (NIH-R1) experiments] after a spaceflight, or 6 h after head-down tilt (HDT) experiments. Apical alterations were noted in choroidal cells from SLS-2 and HDT animals, confirming that weightlessness impaired choroidal structures and functions. However, the presence of small apical microvilli and kinocilia and the absence of vesicle accumulations showed that the apical organization began to be restored rapidly after landing. Very enlarged apical microvilli appeared after 2 days on Earth, suggesting increased choroidal activity. However, as distributions of ezrin and carbonic anhydrase II remained altered in both flight and suspended animals after readaptation to Earth gravity, it was concluded that choroidal structures and functions were not completely restored, even after 2 days in Earth’s gravity.

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