Involvement of malate and mannitol in the diurnal regulation of the water status in members of Oleaceae

• Published in: Trees (Berlin, West) Vol. 12; no. 1; pp. 27 - 34
• Main Authors: PELTIER, J. P, MARIGO, D, MARIGO, G
• Format: Journal Article
• Language: English
• Published: Berlin Springer 01.12.1997; Springer Nature B.V
• Subjects: Agronomy. Soil science and plant productions; Alnus glutinosa; Biological and medical sciences; Diurnal variations; Drought; Droughts; Economic plant physiology; Environmental conditions; Fraxinus excelsior; Fundamental and applied biological sciences. Psychology; Growing season; Habitat; Leaves; Oleaceae; Organic compounds; Plant physiology and development; Quercus robur; Robinia; Solar radiation; Transpiration; Trees; Vapors; Water and solutes. Absorption, translocation and permeability; Water potential; Water relations, transpiration, stomata; Weather; Temperature; Oleaceae; Osmoregulation; Environmental factor; Diurnal variation; Water potential; Luminous intensity; Water regime; Dicotyledones; Angiospermae; Mannitol; Malic acid; Spermatophyta; Hardwood forest tree; Osmotic pressure; Potassium; Comparative study
• ISSN: 0931-1890; 1432-2285
• DOI: 10.1007/s004680050118

This study examines water status regulation in plants of the Oleaceae family and in some other co-occurring species that are exposed to high solar radiation, in the same habitat. Fraxinus excelsior L., one of the most studied Oleaceae in this field exhibited, during the growing season, a close relationship between diurnal variations in leaf water potential and changes in malate, mannitol and K^sup +^ levels, depending on the weather conditions. On sunny days, similar variations can be observed in leaves of the other Oleaceae, with a concomitant decrease in the osmotic potential between predawn and solar noon. Malate, mannitol and the well-known osmoticum K^sup +^, contribute greatly to the osmotic potential decrease. This mechanism, which can be related to the osmotic adjustment described for both drought and salt-affected plants, appears as a general response in plants of the Oleaceae family. Among the other co-occurring species investigated, only Quercus robur L. displayed a similar mechanism under the same environmental conditions, but two other organic compounds, quinic and shikimic acids, are presumably involved. Alnus glutinosa (L.) Gaertn. and Robinia pseudacacia L. responded to a vapor deficit by partial stomatal closure, as transpiration progressed through the morning.[PUBLICATION ABSTRACT]