THE EFFECT OF ABSCISIC ACID ON GROWTH, PHOTOSYNTHETIC RATE AND CARBOHYDRATE METABOLISM IN LEMNA MINOR L.

Abstract

Inclusion of 10‐6 M ABA in the growth medium of Lemna minor L. inhibited frond multiplication rate and increased dry weight and relative growth rate per frond. Sugar and starch levels were increased over and above that expected from growth inhibition alone. Transfer of fronds to normal nutrient, after 6 days growth in 10‐6 M ABA, resulted in a higher growth rate than controls and a rapid decrease in accumulated carbohydrates. Net photosynthetic rate was initially increased, but declined after 2 days growth in the presence of ABA. This decrease in photosynthetic rate is discussed in relation to the accumulation of carbohydrates. Respiration rate did not increase with higher carbohydrate levels in the presence of ABA. Copyright © 1976, Wiley Blackwell. All rights reserved