| Registro completo |
| Provedor de dados: |
Braz. J. Plant Physiol.
|
| País: |
Brazil
|
| Título: |
Limitations to photosynthesis at different temperatures in the leaves of Citrus limon
|
| Autores: |
Pimentel,Carlos
Bernacchi,Carl
Long,Steve
|
| Data: |
2007-06-01
|
| Ano: |
2007
|
| Palavras-chave: |
A/Ci curves
Gas exchange
Lemon
|
| Resumo: |
The response of CO2 assimilation rate (A) to the intercellular partial pressure of CO2 (Ci) was measured on intact lemon leaves over a range of temperatures (10 to 40ºC). The A/Ci response shows how change in the leaf temperature alters the activity of ribulose-1,5-bisphosphate (RuBP) carboxylase-oxygenase (Rubisco) and RuBP regeneration via electron transport. The rate of A reached a maximum of 7.9 to 8.9 µmol m-2 s-1 between 25 and 30ºC, while dark respiration (Rd) increased with temperature from 0.4 µmol m-2 s-1 at 10ºC to 1.4 µmol m-2 s-1 at 40ºC. The maximum rates of carboxylation (Vc,max) and the maximum rates of electron transport (Jmax) both increased over this temperature range from 7.5 to 142 µmol m-2 s-1 and from 23.5 to 152 µmol m-2 s-1, respectively. These temperature responses showed that A can be limited by either process depending on the leaf temperature, when Ci or stomatal conductance are not limiting. The decrease in A associated with higher temperatures is in part a response to the greater increase in the rate of oxygenation of RuBP compared with carboxylation and Rd at higher temperatures. Although A can in theory be limited at higher Ci by the rate of triose-phosphate utilization, this limitation was not evident in lemon leaves.
|
| Tipo: |
Info:eu-repo/semantics/article
|
| Idioma: |
Inglês
|
| Identificador: |
http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202007000200006
|
| Editor: |
Brazilian Journal of Plant Physiology
|
| Relação: |
10.1590/S1677-04202007000200006
|
| Formato: |
text/html
|
| Fonte: |
Brazilian Journal of Plant Physiology v.19 n.2 2007
|
| Direitos: |
info:eu-repo/semantics/openAccess
|
