The Effect of Abscisic Acid and Benzylaminopurine on Photosynthesis and Transpiration Rates of Maize (Zea mays L.) under Water Stress and Subsequent Rehydration
The young plants of maize were cultivated as sand culture under controlled conditions in a greenhouse. The water stress caused by interruption of irrigation for a period of 8 days had the effect of statistically significant decrease of the photosynthesis rate (P N) and the transpiration rate (E) as compared with plants under no stress. When the plants were treated with a 100 μM abscisic acid (ABA) solution before the interruption of irrigation, this had the effect of further decrease of the levels of P N and E during the first period of measurement (3 to 4 days after interruption of irrigation) and the effect of slowing down the development of water stress in the following period (7 to 8 days after interruption of irrigation). ABA applied through irrigation was more effective than the one applied by sprinkling because it significantly increased the water use efficiency (WUE) in the treated plants. Benzylaminopurine (BAP) used as a 10 μM solution brought about an increase of P N and E in comparison with the plants under stress, not treated phytohormones. The result of the combined application of both growth regulators were steady levels of P N during the entire eight-day evaluation of water stress imposed on maize plants. However, during the second period of measuring, the higher levels of E were reflected in a decrease of the WUE level. Two days after irrigation was resumed, the subsequent saturation of plants with water was manifested by an increase of P N in all groups of plants under stress. However, the fairly steady levels remained below the level of P N measured in the control sample under no stress. Rehydration had various effects on E. The level of E increased the most in the case where ABA was used as irrigation. It also increased moderately in the case where ABA was applied by sprinkling and in the case of the plants under stress, not treated phytohormones. On the contrary, E stagnated in the cases with BAP and decreased in the cases where ABA and BAP were applied together.
KeywordsZea mays L. photosynthesis rate transpiration rate mild water stress abscisic acid benzylaminopurine
Unable to display preview. Download preview PDF.
- Davies, W.J., Jeffcoat, B. (ed.). 1999. Importance of Root to Shoot Communication in the Responses to Environmental Stress. British Society for Plant Growth Regulation, Bristol.Google Scholar
- Hejnák, V., Križková, J. 2004. The effect of water stress on photosynthesis of spring barley. Zeszyty problemowe postepów nauk rolniczych 496:241–249.Google Scholar
- Incoll, L.D., Ray, J.P., Jewer, P.C. 1990. Do cytokinins act as root to shoot signals? In: Davies, W.J., Jeffcoat, B. (eds), Importance of Root to Shoot Communication in the Responses to Environmental Stress. British Society for Plant Growth Regulation, Bristol, pp. 185–197.Google Scholar
- Itai, C. 1999. Role of phytohormones in plant response to stresses. In: Lerner, H.R. (ed.), Plant Response to Environmental Stress. From phytohormones to genome reorganization. Marcell Dekker, New York-Basel, pp. 287–301.Google Scholar
- Meyer, S. 1993. Effet de la sécheresse sur la bioenergetique des thylakoides en rélation avec les parametres biochimiques et structuraux des membranes. These de doctorat de l’Université de Paris 6, 175 pp.Google Scholar
- Nilsen, E. T., Orcutt, D.M. 1996. Physiology of Plants under Stress. John Wiley & Sons, New York, pp. 43–190.Google Scholar