Enhanced Rubisco activation associated with maintenance of electron transport alleviates inhibition of photosynthesis under low nitrogen conditions in winter wheat seedlings.
J Exp Bot
; 69(22): 5477-5488, 2018 11 26.
Article
em En
| MEDLINE
| ID: mdl-30239847
ABSTRACT
Studying the response of photosynthesis to low nitrogen (N) and the underlying physiological mechanism can provide a theoretical basis for breeding N-efficient cultivars and optimizing N management. We conducted hydroponic experiments using two wheat (Triticum aestivum) cultivars, Zaoyangmai (low N sensitive) and Yangmai158 (low N tolerant), with either 0.25 mM N as a low N (LN) treatment or 5 mM N as a control. Under LN, a decrease in net photosynthetic rate (Pn) was attributed to reduction in the maximum Rubisco carboxylation rate, which then accelerated a reduction in the maximum ribulose-1,5-bisphosphate regeneration rate, and the reduction in Pn was 5-35% less in Yangmai158 than in Zaoyangmai. Yangmai158 maintained a 10-25% higher Rubisco concentration, especially in the upper leaves, and up-regulated Rubisco activase activity compared with Zaoyangmai to increase the Rubisco activation to sustain Rubisco carboxylation under LN conditions. In addition, Yangmai158 increased electron flux to the photorespiratory carbon oxidation cycle and alternative electron flux to maintain a faster electron transport rate and avoid photodamage. In conclusion, the LN-tolerant cultivar showed enhanced Rubisco activation and sustained electron transport to maintain a greater photosynthetic capacity under LN conditions.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Fotossíntese
/
Ribulose-Bifosfato Carboxilase
/
Triticum
/
Nitrogênio
Tipo de estudo:
Risk_factors_studies
Idioma:
En
Revista:
J Exp Bot
Assunto da revista:
BOTANICA
Ano de publicação:
2018
Tipo de documento:
Article