Publication
Limitations to leaf photosynthesis in field-grown grapevine under drought - metabolic and modelling approaches
| dc.contributor.author | Maroco, João | |
| dc.contributor.author | Rodrigues, M. Lucília | |
| dc.contributor.author | Lopes, Carlos Manuel Antunes | |
| dc.contributor.author | Chaves, Maria Manuela | |
| dc.date.accessioned | 2012-09-21T19:05:37Z | |
| dc.date.available | 2012-09-21T19:05:37Z | |
| dc.date.issued | 2002 | |
| dc.description.abstract | The effects of a slowly-imposed drought stress on gas-exchange, chlorophyll a fluorescence, biochemical and physiological parameters of Vitis vinifera L. leaves (cv. Aragonez, syn. Tempranillo) growing in a commercial vineyard (South Portugal) were evaluated. Relative to well-watered plants (predawn water potential, ΨPD = –0.13 ± 0.01 MPa), drought-stressed plants (ΨPD = –0.97 ± 0.01 MPa) had lower photosynthetic rates (ca 70%), stomatal conductance, and PSII activity (associated with a higher reduction of the quinone A pool and lower efficiency of PSII open centres). Stomatal limitation to photosynthesis was increased in drought-stressed plants relative to well-watered plants by ca 44%. Modelled responses of net photosynthesis to internal CO2 indicated that drought-stressed plants had significant reductions in maximum Rubisco carboxylation activity (ca 32%), ribulose-1,5-bisphosphate regeneration (ca 27%), and triose phosphate (triose-P) utilization rates (ca 37%) relative to well-watered plants. There was good agreement between the effects of drought on modelled biochemical parameters, and in vitro activities of key enzymes of carbon metabolism, namely Rubisco, glyceraldehyde-3-phosphate dehydrogenase, ribulose-5-phosphate kinase and fructose-1,6-bisphosphate phosphatase. Quantum yields measured under both ambient (35 Pa) and saturating CO2 (100 Pa) for drought-stressed plants were decreased relative to well-watered plants, as well as maximum photosynthetic rates measured at light and CO2 saturating conditions (three times ambient CO2 levels). Although stomatal closure was a strong limitation to CO2 assimilation under drought, comparable reductions in electron transport, CO2 carboxylation, and utilization of triose-P capacities were also adaptations of the photosynthetic machinery to dehydration that slowly developed under field conditions. Results presented in this study confirm that modelling photosynthetic responses based on gas-exchange data can be successfully used to predict metabolic limitations to photosynthesis. | por |
| dc.identifier.citation | Functional Plant Biology, 29, 451-459 | por |
| dc.identifier.issn | 1445-4408 | |
| dc.identifier.uri | http://hdl.handle.net/10400.12/1711 | |
| dc.language.iso | eng | por |
| dc.peerreviewed | yes | por |
| dc.publisher | CSIRO Publishing | por |
| dc.subject | Drought | por |
| dc.subject | Enzymes of carbon metabolism | por |
| dc.subject | Gas exchange | por |
| dc.subject | Modelling | por |
| dc.subject | Photosynthesis | por |
| dc.subject | Vitis vinifera | por |
| dc.title | Limitations to leaf photosynthesis in field-grown grapevine under drought - metabolic and modelling approaches | por |
| dc.type | journal article | |
| dspace.entity.type | Publication | |
| oaire.citation.conferencePlace | Collingwood | por |
| oaire.citation.endPage | 459 | por |
| oaire.citation.startPage | 451 | por |
| oaire.citation.title | Functional Plant Biology | por |
| oaire.citation.volume | 29 | por |
| rcaap.rights | restrictedAccess | por |
| rcaap.type | article | por |