Comparative study on energy partitioning in photosystem II of two <Emphasis Type="Italic">Arabidopsis thaliana</Emphasis> mutants with reduced non-photochemical quenching capacity |
| |
Authors: | Szilvia Bajkán Zsuzsanna Várkonyi Endre Lehoczki |
| |
Institution: | 1.Department of Plant Biology,University of Szeged,Szeged,Hungary;2.Institute of Plant Biology,Biological Research Center of the Hungarian Academy of Sciences,Szeged,Hungary |
| |
Abstract: | Lhcb1-2 and PsbS proteins of photosystem II (PSII) have important roles in photoprotective thermal energy dissipation of the
absorbed excess light energy. The light responses of chlorophyll fluorescence parameters were analyzed to examine how the
absence of Lhcb1-2 or PsbS proteins can modify the energy allocation patterns of absorbed light energy in PSII using an antisense
construct of lhcb2 and a psbS deletion (npq4-1) mutant of Arabidopsis thaliana. Both mutants exhibit reduced Stern–Volmer non-photochemical chlorophyll fluorescence quenching (NPQ). Here, we have adopted
an approach, presented by Hendrickson et al. (Photosynth Res 82:73–81, 2004), to gain a better insight into the mechanism of the NPQ in these mutants. We have found no significant differences in the
quantum yields of photochemical energy conversion (ΦPSII) between the mutants and the wild type. Nevertheless, as it was expected, the fraction of the energy, which is dissipated
as heat via regulated pathways in PSII (ΦNPQ) for both mutants, were reduced as compared to the wild type. In a complementary way, the extent of non-regulated non-photochemical
energy loss in PSII (ΦNO) for both mutants was significantly higher than that in the wild type. This reflects, together with the lower ΦNPQ (or NPQ) values, suboptimal capacity of photoprotective reactions at higher light intensities. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|