Contribution and consequences of xylem-transported CO2 assimilation for C3 plants
© 2019 The Authors. New Phytologist © 2019 New Phytologist Trust.
| Veröffentlicht in: | The New phytologist. - 1979. - 223(2019), 3 vom: 12. Aug., Seite 1230-1240 |
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| Format: | Online-Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2019
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| Zugriff auf das übergeordnete Werk: | The New phytologist |
| Schlagworte: | Journal Article Research Support, U.S. Gov't, Non-P.H.S. Brassica napus Populus deltoides CO2 efflux internally transported CO2 leaf photosynthesis models stem [CO2*] tunable diode laser absorption spectroscopy xylem-transported CO2 mehr... |
| Zusammenfassung: | © 2019 The Authors. New Phytologist © 2019 New Phytologist Trust. Traditionally, leaves were thought to be supplied with CO2 for photosynthesis by the atmosphere and respiration. Recent studies, however, have shown that the xylem also transports a significant amount of inorganic carbon into leaves through the bulk flow of water. However, little is known about the dynamics and proportion of xylem-transported CO2 that is assimilated, vs simply lost to transpiration. Cut leaves of Populus deltoides and Brassica napus were placed in either KCl or one of three [NaH13 CO3 ] solutions dissolved in water to simultaneously measure the assimilation and the efflux of xylem-transported CO2 exiting the leaf across light and CO2 response curves in real-time using a tunable diode laser absorption spectroscope. The rates of assimilation and efflux of xylem-transported CO2 increased with increasing xylem [13 CO2 *] and transpiration. Under saturating irradiance, rates of assimilation using xylem-transported CO2 accounted for c. 2.5% of the total assimilation in both species in the highest [13 CO2 *]. The majority of xylem-transported CO2 is assimilated, and efflux is small compared to respiration. Assimilation of xylem-transported CO2 comprises a small portion of total photosynthesis, but may be more important when CO2 is limiting |
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| Beschreibung: | Date Completed 28.02.2020 Date Revised 30.09.2020 published: Print-Electronic Citation Status MEDLINE |
| ISSN: | 1469-8137 |
| DOI: | 10.1111/nph.15907 |