Fluctuations in Sensitivity of the Avena Test Due to Air Pollutants.

Abstract

It was found that when Avena tests were carried out every 3 hours over a 24-hour period simultaneously in filtered and unfiltered air, the diurnal fluctuation which occurred in the plants grown in unfiltered air was absent in those in filtered air, thus indicating that the variability in sensitivity was a result of fluctuating concentrations of air pollutants. A test carried out in the same manner during a smog-free period indicated an absence of diurnal fluctuation even in the case of plants grown in unfiltered air. It is suggested that the cause of decreased response to applied auxin lies not in the destructive effect of peroxides and other air pollutants upon IAA, but rather in an effect on the growth response of the coleoptile itself.