Abstract
Abscisic acid inhibited yellowing of cucumber leaves in low nitrogen conditions
Jyunya Inoue1,Mariko Oka2,Hideyasu Fujiyama2
1Graduate School of Agriculture,Tottori University,
2Faculty of Agriculture,Tottori University, Tottori 680-8553, JAPAN
Nitrogen deficiency has been shown to result in yellowing of mature leaves in higher plants. We found that the application of abscisic acid (ABA) substantially inhibited yellowing of cucumber (Cucumis sativus) leaves grown in low nitrogen medium. Chlorophyll contents in cucumber cultivated in the low nitrogen medium containing ABA significantly increased, especially in cotyledons and immature leaves, as its dose dependent manner. Inhibitory effect of ABA on yellowing leaves depended on its application period. Nitrogen contents, especially nitrate, in cucumber plants grown under low nitrogen conditions in the presence of ABA were higher than those in the absence of ABA. These results suggest that ABA promotes absorption and/or accumulation of nitrate and inhibits yellowing of cucumber plants in low nitrogen conditions.