scholarly journals Measurement of CO2 and H2O Vapor Exchange in Spinach Leaf Discs

1983 ◽  
Vol 71 (1) ◽  
pp. 102-107 ◽  
Author(s):  
Gary C. Harris ◽  
John K. Cheesbrough ◽  
David A. Walker
Keyword(s):  
Leaf Discs ◽  
Spinach Leaf

The role of malate in nitrate reduction in spinach leaves

1980 ◽  
Vol 58 (5) ◽  
pp. 517-521 ◽  
Author(s):  
K. C. Woo ◽  
D. T. Canvin
Keyword(s):  
Nitrate Reduction ◽  
Nitrite Accumulation ◽  
Antimycin A ◽  
Anaerobic Conditions ◽  
Aerobic Conditions ◽  
Leaf Discs ◽  
Spinach Leaf ◽  
Spinach Leaves

In spinach leaf discs the accumulation of nitrite from nitrate reduction under anaerobic conditions in the light in the presence of 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU) was inhibited by air. The inhibition of nitrate reduction by air was reversed by antimycin A but not by rotenone or amytal. The nitrate-reducing system of DCMU-inhibited leaf discs in the light appeared similar to noninhibited leaf discs in the dark. In aerobic conditions, the addition of malate stimulated nitrite accumulation. This stimulation was unaffected by malonate. Under anaerobic conditions, malate reversed the inhibition of nitrate reduction caused by either iodoacetate or arsenite to rates similar to those observed in the dark and in the light with DCMU. Malate can apparently provide a direct source of cytosolic NADH for nitrate reduction.

Chloroplast and Nuclear DNA Content of Cultured Spinach Leaf Discs

1982 ◽  
Vol 33 (4) ◽  
pp. 831-837 ◽  
Author(s):  
M. J. TYMMS ◽  
N. S. SCOTT ◽  
J. V. POSSINGHAM
Keyword(s):  
Dna Content ◽  
Nuclear Dna ◽  
Nuclear Dna Content ◽  
Leaf Discs ◽  
Spinach Leaf

Effects of Green Light on the Chloroplasts of Spinach Leaf Discs

1975 ◽  
Vol 26 (1) ◽  
pp. 33-42 ◽  
Author(s):  
J. V. POSSINGHAM ◽  
D. G. CRAN ◽  
R. J. ROSE ◽  
B. R. LOVEYS
Keyword(s):  
Green Light ◽  
Leaf Discs ◽  
Spinach Leaf

scholarly journals Estimation of the steady-state cyclic electron flux around PSI in spinach leaf discs in white light, CO2-enriched air and other varied conditions

2013 ◽  
Vol 40 (10) ◽  
pp. 1018 ◽  
Author(s):  
Jiancun Kou ◽  
Shunichi Takahashi ◽  
Riichi Oguchi ◽  
Da-Yong Fan ◽  
Murray R. Badger ◽  
...  
Keyword(s):  
Steady State ◽  
Electron Flux ◽  
Leaf Tissue ◽  
Linear Electron ◽  
Total Electron ◽  
Leaf Discs ◽  
Relative Water ◽  
Photochemical Yield ◽  
Spinach Leaf ◽  
Upper Estimate

Cyclic electron flux (CEF) around PSI is essential for efficient photosynthesis and aids photoprotection, especially in stressful conditions, but the difficulty in quantifying CEF is non-trivial. The total electron flux through PSI (ETR1) and the linear electron flux (LEFO2) through both photosystems in spinach leaf discs were estimated from the photochemical yield of PSI and the gross oxygen evolution rate, respectively, in CO2-enriched air. ΔFlux = ETR1 – LEFO2 is an upper estimate of CEF. Infiltration of leaf discs with 150 μM antimycin A did not affect LEFO2, but decreased ΔFlux 10-fold. ΔFlux was practically negligible below 350 μmol photons m−2 s−1, but increased linearly above it. The following results were obtained at 980 μmol photons m−2 s−1. ΔFlux increased 3-fold as the temperature increased from 5°C to 40°C. It did not decline at high temperature, even when LEFO2 decreased. ΔFlux increased by 80% as the relative water content of leaf discs decreased from 100 to 40%, when LEFO2 decreased 2-fold. The method of using ΔFlux as a non-intrusive upper estimate of steady-state CEF in leaf tissue appears reasonable when photorespiration is suppressed.

Sign in / Sign up

Export Citation Format

Share Document