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Quantifying the dynamics of light tolerance in A rabidopsis plants during ontogenesis
Author(s) -
Carvalho Fabricio E. L.,
Ware Maxwell A.,
Ruban Alexander V.
Publication year - 2015
Publication title -
plant, cell and environment
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.646
H-Index - 200
eISSN - 1365-3040
pISSN - 0140-7791
DOI - 10.1111/pce.12574
Subject(s) - photoinhibition , chlorophyll fluorescence , quenching (fluorescence) , photosystem ii , non photochemical quenching , light intensity , fluorescence , botany , ontogeny , chlorophyll , population , plant physiology , juvenile , photosynthesis , chlorophyll a , biophysics , horticulture , biology , photochemistry , chemistry , ecology , optics , physics , medicine , genetics , environmental health
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 (q P ) 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 ∼70 μ mol m −2 s −1 , for 1‐week‐old seedlings, to a maximum of 1385 μ mol m −2 s −1 for 8‐week‐old plants. After 8 weeks, the tolerated light intensity started to gradually decline, becoming only 332 μ mol 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 (p NPQ ) and the electron transport rates ( ETR s). Light tolerance did not, however, show a similar trend to chlorophyll a / b ratios and content of anthocyanins. Our data suggest that p NPQ is crucial in defining the capability of high light tolerance by A rabidopsis plants during ontogenesis.