Article Subject

At the center of every new plant growth cell is an atom of carbon, which the plant absorbs from carbon dioxide in
the immediately surrounding air. As CO2 is used for its carbon, water vapor and Oxygen are released from the plant stomata
as waste. If a plant is "breathing in" carbon dioxide and releasing oxygen as a waste product, what else could the plant
possibly need the oxygen for? The short answer is nutrient absorption. No nutrient absorption occurs at the root zone
unless oxygen is present. At a molecular level oxygen is required to transmit nutrients across the cell wall and into the roots.
The effect of O2 partial pressure on the germination and the respiration of five cultivated species were studied. The
reciprocal of the time necessary to observe rootlet emergence in 50% of the seeds was used to approach the germination
rate. The maximum germination and respiration rates were reached in most seeds at O2 pressures close to that of air.
Decreasing the O2 pressure produced a gradual decrease of the germination rate. Totally five plant seeds are tested for the
oxygen sensing and germination rates. Then the metabolic rates of the corresponding seeds at germination were also tested
by using the standard methods. The seeds could be classed in two groups according to their response to low O2 pressures.
1. Group I includes soya bean, pea and Horse gram:
2. Group II includes rice, wheat.
The germination rate of these seeds was gradually decreased by lowering the O2 partial pressure but germination
still occurred, very slowly, at 0.1 kilopascal; the adenylate energy charge remained higher than 0.6. The metabolic rate of all
these seeds are high during germination .at the of the germination the sugar, protein and lipid concentrations are very high at
the ending of the of the germination these levels are very low

Molecular level oxygen
Nutrient absorption.
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