Quantifying the dynamics of light tolerance in Arabidopsis plants during ontogenesis.
Plant Cell Environ
; 38(12): 2603-17, 2015 Dec.
Article
de En
| MEDLINE
| ID: mdl-26012511
ABSTRACT
The amount of light plants can tolerate during different phases of ontogenesis remains largely unknown. This was addressed here employing a novel methodology that uses the coefficient of photochemical quenching (qP) to assess the intactness of photosystem II reaction centres. Fluorescence quenching coefficients, total chlorophyll content and concentration of anthocyanins were determined weekly during the juvenile, adult, reproductive and senescent phases of plant ontogenesis. This enabled quantification of the protective effectiveness of non-photochemical fluorescence quenching (NPQ) and determination of light tolerance. The light intensity that caused photoinhibition in 50% of leaf population increased from â¼70 µmol m(-2) s(-1) , for 1-week-old seedlings, to a maximum of 1385 µmol m(-2) s(-1) for 8-week-old plants. After 8 weeks, the tolerated light intensity started to gradually decline, becoming only 332 µmol m(-2) s(-1) for 13-week-old plants. The dependency of light tolerance on plant age was well-related to the amplitude of protective NPQ (pNPQ) and the electron transport rates (ETRs). Light tolerance did not, however, show a similar trend to chlorophyll a/b ratios and content of anthocyanins. Our data suggest that pNPQ is crucial in defining the capability of high light tolerance by Arabidopsis plants during ontogenesis.
Mots clés
Texte intégral:
1
Collection:
01-internacional
Base de données:
MEDLINE
Sujet principal:
Arabidopsis
Langue:
En
Journal:
Plant Cell Environ
Sujet du journal:
BOTANICA
Année:
2015
Type de document:
Article
Pays d'affiliation:
Royaume-Uni