Figure 2
Comparison of raw PS II structural and functional parameters of Alyssum montanum leaves between non-metallicolous (NM) and metallicolous (M) ecotypes growing on control and heavy metal-enriched (HM) media. Different letters indicate statistically significant difference at P < 0.05 within each parameter according to two-way ANOVA and post hoc Tukey’s test. Abbreviations: F0 minimum fluorescence, when all PSII reaction centers (RCs) are open, FM maximum fluorescence, when all PSII reaction centers are closed, Area total complementary area between the fluorescence induction curve and FM, FV variable fluorescence, FV/FM maximum quantum yield of PSII, FV/F0 efficiency of the oxygen-evolving complex on the donor side of the PSII, VJ relative variable fluorescence at 2 ms (J-step), that refers to the number of closed RCs relative to the total number of RCs, VI relative variable fluorescence at 30 ms (I-step); that reflects the ability of PSI and its acceptors to oxidize reduced plastoquinone, Sm normalized total complementary area above the OJIP transient (reflecting multiple-turnover QA reduction events) or total electron carriers per RC, ABS/RC absorption flux per RC; that reflects the proportion between chlorophyll a molecule amounts in fluorescence-emitting antenna complexes and the active reaction centers, TRo/RC trapped energy flux per RC at t = 0, ETo/RC electron transport flux per RC at t = 0, DIo/RC dissipated energy flux per RC at t = 0, ABS/CSo absorption flux per CS at t = 0; represents the amount of photon energy absorbed by the antenna associated with active and inactive reaction centres of PSII and their relationship, TRo/CSo trapped energy flux per CS at t = 0, ETo/CSo electron transport flux per CS at t = 0, DIo/CSo dissipated energy flux per CS at t = 0, RC/CSo amount of active PSII RCs per CS at t = 0, φPo maximum quantum yield of primary photochemistry at t = 0; that indicates the probability of trapping the energy of absorbed photons by PSII reaction centers, φEo quantum yield for the reduction of end acceptors of PSI per photon absorbed, ψEo probability (at time 0) that trapped exciton moves an electron into the electron transport chain beyond QA, ρRo efficiency with which a trapped exciton can move an electron into the electron transport chain from QA‾ to the PSI and electron acceptors, δRo efficiency with which an electron can move from the reduced intersystem electron acceptors to the PSI end electron acceptors, φRo quantum yield for the reduction of end acceptors of PSI per photon absorbed.
