Rooting abscisic acid

Cornish, K. and Zeevaart, J.A.D. (1985). Abscisic acid accumulation by roots of Xanthium strumarium L. and Lycopersicon esculentum Mill, in relation to water stress. Plant Physiology, 79, 653-8. 

Lachno, D.R. Baker, D.A. (1986). Stress induction of abscisic acid in maize roots. Physiologia Plantarum, 68, 215-21. 

Walton, D.C., Harrison, M.A. Cote, P. (1976). The effects of water stress on abscisic acid levels and metabolism in roots of Phaseolus vulgaris and other plants. Planta, 131, 141. ... 

Zhang, J. Davies, W.J. (1989). Abscisic acid produced in dehydrating roots may enable the plant to measure the water status of the soil. Plant, Cell and Environment, 12, 73-81. 

Zhang, J., Schurr, U. Davies, W.J. (1987). Control of stomatal behaviour by abscisic acid which apparently originates in the roots. Journal of Experimental Botany, 38,1174-81. 

Jones, H., Leigh, R.A., Tomos, A.D. Wyn Jones, R.G. (1987). The effect of abscisic acid on cell turgor presures, solute content and growth of wheat roots. Phytochemistry, 170, 257-63. 

Thompson, A. J., J. Andrews et al. (2007). Overproduction of abscisic acid in tomato increases transpiration efficiency and root hydraulic conductivity and influences leaf expansion. Plant Physiol. 143(4) ... 

Cammue, B.P.A., Broekaert, W.F., Kellens, J.T.C., Raikhel, N.V. Peumans, W.J. (1989). Stress-induced accumulation of wheat germ agglutinin and abscisic acid in roots of wheat seedlings. Plant Physiology 91, 1432-5. 

The phenolic acids of interest here [caffeic acid (3,4-dihydroxycinnamic acid), ferulic acid (4-hydroxy-3-methoxycinnamic acid), p-coumaric acid (p-hydroxycinnamic acid), protocatechuic acid (3,4-dihydroxybenzoic acid), sinapic acid (3,5-dimethoxy-4-hydroxyxinnamic acid), p-hydroxybenzoic acid, syringic acid (4-hydroxy-3,5-methoxybenzoic acid), and vanillic acid (4-hydroxy-3-methoxybenzoic acid)] (Fig. 3.1) all have been identified as potential allelopathic agents.8,32,34 The primary allelopathic effects of these phenolic acids on plant processes are phytotoxic (i.e., inhibitory) they reduce hydraulic conductivity and net nutrient uptake by roots.1 Reduced rates of photosynthesis and carbon allocation to roots, increased abscisic acid levels, and reduced rates of transpiration and leaf expansion appear to be secondary effects. Most of these effects, however, are readily reversible once phenolic acids have been depleted from the rhizosphere and rhizoplane.4,6 Finally, soil solution concentrations of... 

The uptake of radioactive abscisic acid by radish leaf discs has been described87 and its metabolism (to unidentified compounds) by root segments of Phaseolus coccineus88 and by pea seedlings during and after water stress has been reported.89... 

Abscisic acid (ABA) levels in rice plants, 308,31Or levels in squash hypocotyls, 315/.316 Active component of brassins identification, 9,lQf pilot plant extraction, 6,7/,8 solvent partition and column chromatography, 8 Adventitious root(s) development, 233,234r,235 formation, 247 Agriculture, application of 24-epibrassinolide, 280-290 22-Aldehydes, synthesis of brassinosteroids, 47-50f a hormone function, description for brassins, 4... 

Abscisic acid (ABA) is a 15-carbon acid, related in structure to one end of a carotene molecule [83], Four stereoisomers exist, differing in the orientation of the carboxyl group and the sidechain attachment to the ring. The natural ABA is the c/y-(+)-isomer shown in Fig. le. It is made from zeaxanthin via xanthoxin, probably in plastids (see Chapter 8). ABA can be made in all parts of a plant, with the leaves and the root cap being sites of extensive synthesis. It can be metabolized into phaseic acid, which is active in some, but not all ABA-sensitive processes [83]. 

Chang, T.Y., Senn, A., Pilet, P.E., 1983. Effect of abscisic acid on maize (Zea maize vs. LG-11) root protoplasts. Zeitschrift fiir Pflanzenphysiologie 110, 127-134. 

Transpiration is a process that involves loss of water vapour through the stomata of plants. The loss of water vapour from the plant cools the plant down when the weather is very hot, and water from the stem and roots moves upwards or is pulled into the leaves. When less water is available for the plants, dehydrated mesophyll cells release the plant hormone abscisic acid, which causes the stomatal pores to close and reduce the loss of water during release of oxygen and intake of carbon dioxide. Fig. 2.7 (a) shows the transpiration effect in plants with open and closed stomata. 

Fujii, H., Verslues, P.E., and Zhu, J.K. (2007) Identification of two protein kinases required for abscisic acid regulation of seed germination, root growth, and gene expression in Arabidopsis. Plant Cell, 19, 485 -494. 

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