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| Titel |
Adaptation of carbon allocation under light and nutrient reduction |
| VerfasserIn |
Frederik Wegener, Christiane Werner |
| Konferenz |
EGU General Assembly 2015
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250104637
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| Publikation (Nr.) |
 EGU/EGU2015-4068.pdf |
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| Zusammenfassung |
| The allocation of recently assimilated carbon (C) by plants depends on developmental stage
and on environmental factors, but the underlying mechanisms are still a matter of debate.
Whereas shifts in the allocation of photosynthates induced by reduced water availability,
enhanced temperature and CO2 concentration were recently investigated in various studies,
less is known about the response to light and nutrient reduction. We induced different
allocation patterns in the Mediterranean shrub Halimium halimifolium L. by a reduction of
light (Low L treatment) and nutrient availability (Low N treatment) and analysed allocation
parameters as well as morphological and physiological traits for 15 months. Finally, we
conducted a 13CO2 pulse-labelling and followed the fate of recently assimilated carbon
to eight different classes of plant tissues and respiration for 13 days. The results
revealed a high intraspecific variability in C distribution to tissues and in respiration.
Allocation changes even varied within leaf and stem tissue classes (e.g. more C in main
stems, less in lateral stems). These results show that the common separation of
plant tissues in only three classes, i.e. root, shoot and leaf tissues, can result in
missing information about allocation changes. The nutrient reduction enhanced the
transport of recently assimilated C from leaves to roots in terms of quantity (c.
200%) and velocity compared to control plants. Interestingly, a 57% light reduction
enhanced photosynthetic capacity and caused no change in final biomass after 15
months. Therefore, our results support the recently discussed sink regulation of
photosynthesis.
Finally, our results indicate that growing heterotrophic tissues strongly reduce the C loss
from storage and structural C pools and therefore enhance the fraction of recent assimilates
used for respiration. We propose that this interruption of the C reflux from storage
and structural C pools could be a control mechanism for C translocation in plants. |
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