ISHS Acta Horticulturae 449: II International Symposium on Irrigation of Horticultural Crops
ON THE CONTRIBUTION OF MESOPHYLL RESISTANCE TO CO2 DIFFUSION TO PHOTOSYNTHESIS LIMITATION DURING WATER AND SALT STRESS |
| Authors: | F. Loreto, S. Delfine, A. Alvino |
| Keywords: | Resistances to CO2 diffusion, electron transport, fluorescence, gas exchange, Spinacia oleracea |
| Abstract:
We estimated from simultaneous measurements of fluorescence and gas exchange the mesophyll conductance to CO2 diffusion and the CO2 concentration in the chloroplasts of spinach leaves exposed to water and salt stress. Both stresses caused a reduction of mesophyll conductance with respect to controls. Because of the simultaneous reduction of mesophyll and stomatal conductance the CO2 concentration in the chloroplasts was also lower than in controls. Photosynthesis responses to chloroplast CO2 concentration suggest that diffusive resistances are mainly responsible for photosynthesis limitation of stressed plants at ambient CO2. However, low photosynthesis in salt stressed leaves at CO2 higher than ambient indicates that metabolic limitations likely take place when the stress is heavy. | |
Download Adobe Acrobat Reader (free software to read PDF files) | |
