Elevated atmospheric CO2 mitigated photoinhibition in a tropical tree species, Gmelina arborea

Growth, physiological and biochemical responses of Meliaceae species - Azadirachta indica and Melia dubia to elevated CO2 concentrations

“…Elevated CO 2 concentration of 600 ppm was favourable for enhancement of total chlorophylls in A. indica and M. dubia. This is contrary to reports that chlorophylls and stomatal conductance decreased in plants grown under elevated CO 2 compared to ambient CO 2 level [39]. Further, the accumulation of carbohydrates is reported to have a feedback inhibitory effect on photosynthetic rate, thereby reducing the chlorophyll content both a and b in this species [40].…”

Interspecific competition changes photosynthetic and oxidative stress response of barley and barnyard grass to elevated CO2 and temperature

“…3). The higher performance indices in plants grown in the elevated CO 2 and temperature also suggest an efficient overall performance of PSII photosynthetic machinery in these plants (Rasineni et al 2011). Interspecific competition decreased PI abs and increased DIo/CSm of barley under elevated CO 2 and temperature conditions.…”

“…This approximation was performed by assuming that either F o or F m are reasonable measures of the absorption energy flux per excited CS of leaf sample (ABS/CS) in arbitrary units of a particular leaf sample in the dark-adapted state (Strasser and Strasser 1995). The translation of the measured fluorescence parameters into JIP-test parameters provides information on the stepwise flow of energy through PSII at different levels (Rasineni et al 2011). A higher RC/CSo (of monoculture grown barnyard grass) induced by CO 2 and temperature suggests a larger proportion of active photosystem II (PSII) centers.…”

“…The transients were induced by 5 s illumination with an array of three light emitting diodes providing a maximum light intensity of 1800 μmol (photon) m −2 s −1 and a homogenous irradiation over a 4-mm diameter leaf area. The fast fluorescence kinetics (f 0 to f M ) was recorded from 10 μs to 1 s. The fluorescence intensity at 50 μs was considered as f 0 (Rasineni et al 2011). Analysis of the fluorescence transients using the JIP-test Raw fluorescence OJIP transient, which reflects the reduction in the photosynthetic electron transport chain (Lin et al 2009), was transferred with WINPEA 32 software and BiolyzerP3 to a spreadsheet (Strasser andStrasser 1995, Rasineni et al 2011). The translation of the measured parameters into JIP-test parameters provided the information on the stepwise flow of energy through PSII at different levels such as specific fluxes on the level of the excited leaf cross-section (CS) (absorption [ABS/CSm], trapping [TRo/CSm], dissipation [DIo/CSm] and electron transport [ETo/CSm]).…”

“…The density of RCs (QA-reducing PSII reaction centers) was calculated as RC/CSo = Φ Po (V J /Mo) (ABS/CSo). The detailed formulae and terms used by the JIP-test for analysis of the fluorescence transient O-J-I-P are given in Table S1 (Lin et al 2009, Rasineni et al 2011). …”