scholarly journals Studies on the Nitrogen Metabolism of the Barley Plant (Hordeum Sativum)

1950 ◽  
Vol 3 (4) ◽  
pp. 474 ◽  
Author(s):  
HS McKee
Keyword(s):  
Nitrogen Metabolism ◽  
Constant Temperature ◽  
Barley Plant ◽  
Mature Leaves ◽  
Early Stages ◽  
Solid Nitrogen ◽  
Detached Leaves ◽  
Barley Leaf

In detached harley leaves held at constant temperature in the dark, thereis an increase in "soluble" and a corresponding decrease in "solid" nitrogen. Inmature leaves, glutamine accumulates in the early stages of starvation and laterdecreases concurrently with an increase in asparagine. In detached seedlingleaves, the glutamine content remains low throughout, the sequence of eventsotherwise resembling that found with mature leaves. Changes in the nitrogenousfractions during autolysis, in sterile conditions, of barley leaf tissuediffer greatly from those found with intact detached leaves. "Soluble" nitrogenincreases, but neither amide nor ammonia accumulates.

scholarly journals Stress Metabolism I. Nitrogen Metabolism and Growth in the Barley Plant During Water Stress

1973 ◽  
Vol 26 (1) ◽  
pp. 45 ◽  
Author(s):  
TN Singh ◽  
IG Paleg ◽  
D Aspinall
Keyword(s):  
Water Stress ◽  
Water Deficit ◽  
Nitrogen Metabolism ◽  
Floral Development ◽  
Dry Weight ◽  
Barley Plant ◽  
Main Shoot ◽  
Leaf Dry Weight

An induced water deficit in lO-day barley seedlings resulted in a decrease in leaf dry weight within a 28-hr period, although the shoots and roots continued to increase in weight. Primordium formation and apex elongation on the main shoot were also inhibited but floral development at the apex continued.

scholarly journals The Role of Leaves and Carbohydrates in Flowering of Protea cv. Lady Di

HortScience ◽  
2001 ◽  
Vol 36 (5) ◽  
pp. 905-908
Author(s):  
Audrey I. Gerber ◽  
Karen I. Theron ◽  
Gerard Jacobs
Keyword(s):  
Flowering Time ◽  
Growth And Development ◽  
Dry Weight ◽  
Early Growth ◽  
Major Portion ◽  
Inflorescence Development ◽  
Mature Leaves ◽  
Early Stages

Inflorescence initiation in Protea cv. Lady Di (P. magnifica Link × P. compacta R. Br.) occurs predominantly on the spring growth flush when it is subtended by one or more previous growth flushes. Mature, over-wintering leaves are essential for induction of flowering in `Lady Di', and are also crucial to the early stages of inflorescence initiation and differentiation. Defoliation before elongation of the spring growth flush was complete prevented flowering, and shoots either remained vegetative or produced inflorescences that aborted. Levels of carbohydrates in the stem and leaves of overwintering shoots were low, and early growth and development of both the spring flush and inflorescence were, therefore, supported by current photosynthates from the mature leaves on the overwintering shoot. Likewise, reserve carbohydrates available in the flowering shoot were insufficient to account for the rapid increase in dry weight during the major portion of growth of the spring flush and inflorescence. This increase occurred after elongation of the spring flush was complete and was supported by current photosynthates from the leaves of the spring flush. Defoliation treatments that did not prevent inflorescence initiation had no effect on inflorescence development or on flowering time.

scholarly journals Nitric oxide emission from barley seedlings and detached leaves and roots treated with nitrate and nitrite

2010 ◽  
Vol 56 (No. 5) ◽  
pp. 201-208 ◽  
Author(s):  
J. Chen ◽  
Q. Xiao ◽  
F.H. Wu ◽  
Z.M. Pei ◽  
J. Wang ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Anaerobic Condition ◽  
Barley Plant ◽  
No Emission ◽  
Normal Environment ◽  
Detached Leaves ◽  
Barley Leaves ◽  
Nitrate And Nitrite ◽  
Whole Plants ◽  
Chemiluminescence Detector

Nitric oxide (NO) emission from detached barley leaves, roots and whole plants treated with various nitrate or nitrite concentrations under light/dark and aerobic/anaerobic conditions was quantified by using a chemiluminescence detector. NO emission from detached tissues and whole plants treated with moderate nitrate concentration (60mM) was relatively higher under anaerobic condition, and was positively correlated with nitrite concentration. Darkness and anaerobic condition remarkably induced NO emission from detached barley leaves. On the contrary, NO emission from detached roots and whole plants was relatively higher in light. As for whole plants treated with 60mM nitrate and 12mM nitrite, the pattern of NO emission in normal environment was broken by light-dark and aerobic-anaerobic transition. Light and anaerobic condition induced NO emission significantly in the whole plant. The whole barley plant emitted significantly higher amount of NO than detached leaves or roots.

Probing the circadian control of phosphoenolpyruvate carboxylase kinase expression in Kalanchoë fedtschenkoi

2002 ◽  
Vol 29 (6) ◽  
pp. 663 ◽  
Author(s):  
James Hartwell ◽  
Gillian A. Nimmo ◽  
Malcolm B. Wilkins ◽  
Gareth I. Jenkins ◽  
Hugh G. Nimmo
Keyword(s):  
Phosphoenolpyruvate Carboxylase ◽  
Crassulacean Acid Metabolism ◽  
Acid Metabolism ◽  
Constant Darkness ◽  
Cam Plants ◽  
Mature Leaves ◽  
Circadian Control ◽  
Detached Leaves ◽  
Translatable Mrna ◽  
Kinase Expression

This paper originates from a presentation at the IIIrd International Congress on Crassulacean Acid Metabolism, Cape Tribulation, Queensland, Australia, August 2001. In crassulacean acid metabolism (CAM) plants, phosphoenolpyruvate carboxylase (PEPC) kinase is expressed at night under the control of a circadian oscillator. We have proposed that this is an indirect effect, secondary to circadian fluctuations in the level of a metabolite, possibly cytosolic malate, resulting from a primary effect on the permeability of the tonoplast (Nimmo 2000, Trends in Plant Science 5, 75-80). Here we show that the nocturnal accumulation of PEPC kinase translatable mRNA and phosphorylation of PEPC in Kalanchoë fedtschenkoi is blocked by the protein phosphatase inhibitor cantharidin. This implicates protein dephosphorylation in the circadian pathway that regulates expression of PEPC kinase. We also show that the effect of reducing the temperature from 30 to 15 °C on CO2 fixation by detached leaves held in constant darkness and normal air is 'gated' by the circadian clock. This strongly supports the view that the effect of the clock on the expression of PEPC kinase is secondary rather than direct. We have developed a non-aqueous fractionation protocol that separates the cytosolic material in mature leaves from vacuolar material. The cytosolic malate in mature leaves represents a very small part of the total malate, and its concentration cannot be measured precisely by this method.

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