Influence of irradiation on the distribution of growth in dark-grown Avena seedlings

The influence of red and blue light on the distribution of growth in excised dark-grown seedlings of Avena sativa was studied. The changes in growth distribution seem to be in agreement with the hypothesis that light causes a decrease in transport of auxins from the tip downward, resulting in a higher concentration of auxins in the apical, and a lower concentration in the basal parts of the seedlings.