Differences in the effects of simulated sea aerosol on water relations, salt content, and leaf ultrastructure of rock-rose plants.
White-leaf rock-rose (Cistus albidus L.) and Montpellier rock-rose (C. monspeliensis L.) plants were sprayed 2 to 3 min per day over a 7-d period, in an unheated plastic greenhouse, with different aqueous solutions containing deionized water alone (control); an anionic surfactant (sodium dodecylbenzenesulfonate 82.5%, 50 mg L(-1)) (S1); a solution simulating the composition of sea aerosol (S2); and a solution simulating sea aerosol with anionic surfactant (S3). White-leaf rock-rose was more sensitive to sea aerosol, showing greater leaf damage and markedly decreased growth, and the presence of surfactant enhanced the phytotoxic effect leading to greater increases in mortality. Montpellier rock-rose did not appear to be more adversely affected when surfactant was used in combination with sea aerosol, and manifested slight or less severe symptoms than white-leaf rock-rose. There was a significant increase in leaf turgor potential in the plants treated with both sea aerosol treatments by osmotic adjustment effect. The decrease in photosynthesis level seems to be due to both stomatal and nonstomatal factors. The results of microscopical analysis of Montpellier rock-rose plants show that sea aerosol treatment caused alterations in the chloroplast structure, reducing the starch grain and swelling the thylakoid membranes. The results of this study indicated that Montpellier rock-rose was more tolerant to sea aerosol than white-leaf rock-rose, showing a lower reduction in plant growth and less leaf damage, probably because of its ability to compartmentalize the toxic ions at the intracellular level.
Sánchez-Blanco
M J
MJ
Centro de Edafología y Biología Aplicada del Segura (CSIC), P.O. Box 164, E-30100 Espinardo, Murcia, Spain. quechu@cebas.csic.es
Rodríguez
P
P
Olmos
E
E
Morales
M A
MA
Torrecillas
A
A
D000336:Aerosols; D029758:Cistus / Q000737:chemistry* / Q000502:physiology* / Q000648:ultrastructure; D009995:Osmosis; D018515:Plant Leaves / Q000648:ultrastructure; D012623:Seawater; D012965:Sodium Chloride / Q000493:pharmacokinetics; D014882:Water-Electrolyte Balance
D000336:Aerosols; D012965:Sodium Chloride