scholarly journals Stimulation of Nitrate and Nitrite Efflux by Ammonium in Barley (Hordeum vulgare L.) Seedlings

1994 ◽  
Vol 106 (4) ◽  
pp. 1293-1301 ◽  
Author(s):  
M. Aslam ◽  
R. L. Travis ◽  
R. C. Huffaker
Keyword(s):  
Hordeum Vulgare ◽  
Hordeum Vulgare L ◽  
Nitrate And Nitrite ◽  
Stimulation Of

Characterization of nitrate and nitrite uptake in barley (Hordeum vulgare L.) seedlings

1981 ◽  
Vol 9 (5) ◽  
pp. 477-477
Author(s):  
JESUS M. IBARLUCEA ◽  
JOSE M. MACARULLA ◽  
JUAN L. SERRA
Keyword(s):  
Hordeum Vulgare ◽  
Hordeum Vulgare L ◽  
Nitrite Uptake ◽  
Nitrate And Nitrite

Ultrastructure and Senescence in an Achloroplastic Mutant of Hordeum vulgare L. cv. Dyan

1992 ◽  
Vol 50 (1) ◽  
pp. 844-845
Author(s):  
R.H.M. Cross ◽  
C.E.J. Botha ◽  
A.K. Cowan ◽  
B.J. Hartley
Keyword(s):  
Cell Wall ◽  
Hordeum Vulgare ◽  
Leaf Tissue ◽  
Ultrastructural Changes ◽  
Hordeum Vulgare L ◽  
Mesophyll Cells ◽  
Lethal Mutant ◽  
Cytoplasmic Matrix ◽  
Close Proximity ◽  
Pinocytotic Vesicles

Senescence is an ordered degenerative process leading to death of individual cells, organs and organisms. The detection of a conditional lethal mutant (achloroplastic) of Hordeum vulgare has enabled us to investigate ultrastructural changes occurring in leaf tissue during foliar senescence.Examination of the tonoplast structure in six and 14 day-old mutant tissue revealed a progressive degeneration and disappearance of the membrane, apparently starting by day six in the vicinity of the mitochondria associated with the degenerating proplastid (Fig. 1.) where neither of the plastid membrane leaflets is evident (arrows, Fig. 1.). At this stage there was evidence that the mitochondrial membranes were undergoing retrogressive changes, coupled with disorganization of cristae (Fig. 2.). Proplastids (P) lack definitive prolamellar bodies. The cytoplasmic matrix is largely agranular, with few endoplasmic reticulum (ER) cisternae or polyribosomal aggregates. Interestingly, large numbers of actively-budding dictysomes, associated with pinocytotic vesicles, were observed in close proximity to the plasmalemma of mesophyll cells (Fig. 3.). By day 14 however, mesophyll cells showed almost complete breakdown of subcellular organelle structure (Fig. 4.), and further evidence for the breakdown of the tonoplast. The final stage of senescence is characterized by the solubilization of the cell wall due to expression and activity of polygalacturonase and/or cellulose. The presence of dictyosomes with associated pinocytotic vesicles formed from the mature face, in close proximity to both the plasmalemma and the cell wall, would appear to support the model proposed by Christopherson for the secretion of cellulase. This pathway of synthesis is typical for secretory glycoproteins.

ИЗМЕНЧИВОСТЬ ЯЧМЕНЯ (Hordeum vulgare L.) РАЗНОГО ГЕОГРАФИЧЕСКОГО ПРОИСХОЖДЕНИЯ ПО ЭЛЕМЕНТАМ СТРУКТУРЫ УРОЖАЯ

2012 ◽  
pp. 33-40
Author(s):  
А.В. ЖЕЛЕЗНОВ ◽  
◽  
Н.Б. ЖЕЛЕЗНОВА ◽  
Т.В. КУКОЕВА ◽  
Н.В. БУРМАКИНА ◽  
...  
Keyword(s):  
Hordeum Vulgare ◽  
Hordeum Vulgare L
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