Photosynthesis is limited at high leaf to air vapor pressure deficit in a mutant of Arabidopsis thaliana that lacks trienoic fatty acids |
| |
Authors: | Poulson Mary E. Edwards Gerald E. Browse John |
| |
Affiliation: | (1) Department of Biological Sciences, Idaho State University, Campus Box, 8007, Pocatello, ID 83209-8007, USA;(2) Institute of Biological Chemistry, USA;(3) School of Biological Sciences, Washington State University, Pullman, WA 99164-6340, USA |
| |
Abstract: | We have investigated the role of polyunsaturated fatty acids in photosynthesis using a triple mutant of Arabidopsis thaliana that lacks trienoic fatty acids (fad 3-2 fad 7-2 fad 8). Though this mutant is male sterile, vegetative growth and development under normal conditions are largely unaffected (McConn and Browse, 1996 Plant Cell 8: 403–416). At 0.2–1.0 kPa vapor pressure deficit (low VPD), maximum photosynthetic rates of wild-type and mutant plants were similar while stomatal conductance rates were up to 2 times higher in mutant plants. However, light-saturated rates of carbon assimilation and stomatal conductance in the mutant were lower than in wild-type plants when measured at ambient (35 Pa) CO2 and 2.0–2.8 kPa vapor pressure deficit (high VPD). The limitation to photosynthesis in the mutant plants at high VPD was overcome by saturating partial pressures of CO2 suggesting a stomatal limitation. Chlorophyll fluorescence measurements indicate that differences observed in maximum assimilation rates were not due to limitations within the photochemical reactions of photosynthesis. Stomatal response to VPD and intrinsic water use efficiency was drastically different in mutant versus wild-type plants. The results of this investigation indicate that for Arabidopsis, polyunsaturated fatty acids may be an important determinant of responses of photosynthesis and stomatal conductance to environmental stresses such as high VPD. This revised version was published online in June 2006 with corrections to the Cover Date. |
| |
Keywords: | Arabidopsis fatty acid content fatty acid desaturases mouse-ear-cress photosynthesis stomatal conductance vapor pressure deficit |
本文献已被 PubMed SpringerLink 等数据库收录! |
|