The effect of abscisic acid on root and shoot growth of cauliflower plants

Abstract

Addition of abscisic acid (ABA) to the nutrient solution increased the root to shoot ratio of hydroponically-grown cauliflower plants by reducing the dry weight of the shoot and increasing that of the root . At concentrations higher than 10' M, ABA increased root branching and root hair formation . Root extension was inhibited in plants kept continuously in solutions containing high ABA concentrations but following removal from the ABA solution root elongation was increased in comparison with plants given no ABA treatment . This elongation was greatest in plants with increased root branching caused by higher ABA concentrations .

Water Deficit and Abscisic Acid Cause Differential Inhibition of Shoot versus Root Growth in Soybean Seedlings

“…This result was reproduced (Fig. 6, A and B; induced translation products are numbered [1][2][3][4][5][6][7] [circles]; products which are downregulated are bracketed and labeled E [20] and compared to changes induced by exogenous ABA; Fig. 6, C and D).…”

“…For example, the similarity between the effects ofwater deficit and ABA treatment suggests that the influence of water deficit could be, in part, mediated by changing endogenous ABA levels. Increases in the root/shoot growth ratio have been induced by water deficit (which results in high endogenous ABA levels) and exogenous ABA (4,35). These observations suggest the possible involvement of ABA in the differential response ofroots and shoots to water deficit.…”

Is coordination of leaf and root growth mediated by abscisic acid? Opinion

“…Barlow and Pitet, 1984;Cranaer and Jones, 1996;Robertson et al, 1990), however, it can be stimulated (e.g. Biddington and Dearman, 1982;Creelman et al, 1990;Watts et al, 1981). ABA applied in solution to roots of intact Capsicum, maize and soybean plants produced similar enhancing effects on root growth as did withholding of water (Creelman et al, 1990;Watts et al, 1981).…”

“…Creelman et al, 1990;Robertson et al, 1990) and sometimes it causes a sustained increase in root growth (e.g. Biddington and Dearman, 1982;Watts et al, 1981). ABA certainly has an essential role in the differential regulation of shoot and root growth under water stress.…”

Water Deficit-Induced Changes in Abscisic Acid, Growth, Polysomes, and Translatable RNA in Soybean Hypocotyls

“…Increases in ABA content have been reported in a number of plant species experiencing water deficits (23,25,26). Furthermore, applied ABA has been shown to result in stomatal closure (13), enhanced water flux through roots (1 1), increased root/shoot ratios (24), reduced leaf growth (18), and decreased hypocotyl growth (19) and dry weight accumulation (1,24). Increased endogenous ABA content has been correlated with decreased hypocotyl growth rates (20).…”