Fertilization and seasonality influence on the photochemical performance of tree legumes in forest plantation for area recovery in the Amazon

Abstract

N-fixing leguminous species can reach atmospheric dinitrogen gas (N2), having an advantage under N-limited degraded environments. These N-fixers are constantly used as facilitative species. Chlorophyll a fluorescence (ChF) acknowledges how different species take up and use light energy during photosynthesis. These techniques assess stress and performance responses to photosynthesis and are used for the selection of species with potential for reforestation. Six Fabaceae species were selected for this study: three nonfixing species (Cenostigma tocantinum, Senna reticulata and Dipteryx odorata) and three N-fixing species (Clitoria fairchildiana, Inga edulis and Acacia spp.). Variations in chlorophyll fluorescence under high vs. low water and nutrient conditions were studied. Multivariate analysis was performed to detect the effects of seasonality and fertilization on dark-adapted ChF two years after the experiment was established. The correlation among ChF variables and growth, photosynthesis and foliar nutrient concentrations was evaluated. Under high water- and nutrient-availability conditions, plants exhibited an enhanced performance index on absorption basis values correlated with electron transport fluxes. Under drought and nutrient-poor conditions, most species exhibit increased energy dissipation as photoprotection. High interspecific variation was found; therefore, species-specific responses should be considered in future ChF studies. Corroborating the ability to colonize high-light environments, N-fixers showed an increased performance index correlated with electron transport and Zn and N foliar concentrations. Negative correlations were found between photosynthesis and trapped fluxes. Diameter growth was positively correlated with electron transport fluxes. Given the different responses among species, ChF is an effective technique to screen for seasonality, fertilization and species effects and should be considered for use during forest restoration. Finally, the addition of fertilization treatments may facilitate tropical forest restoration due to the importance of nutrients in physiological processes. N-fixers showed high photochemical performance and tolerance to abiotic stress in degraded areas and therefore should be included to support ecosystem biomass restoration.

AtMYB72 aggravates photosynthetic inhibition and oxidative damage in Arabidopsis thaliana leaves caused by salt stress

“…Their changes during environmental stress can be used to judge the degree of damage to photosynthetic organs and visualize the disturbance in thylakoid membrane caused by stress. 75 , 76 In this experiment, the decrease of F v / F m and PI ABS of OE-10 lines under salt stress was significantly greater than that of Col-0, indicating that MYB72 transcription factor significantly reduced the PSII photochemical activity and NaCl tolerance of A. thaliana . To further analyze the effect of MYB72 on PSII status under salt stress, we standardized the obtained original OJIP curve.…”

The Role of Phosphate Fertilization on Physiological Responses of the Young Bertholletia excelsa Plants Grown in a P-Deficient Amazon Ferralsol

“…This can be verified by the greater increase in above-ground biomass, larger leaf area, and greater leaf gain, and this contributes to the carbon gain since it is directly related to the photosynthetic capacity of plants. Plants with larger leaf areas and leaf gains have larger surface areas to capture light and, consequently, a higher biomass content [ 39 ].…”

“…Dry biomass accumulation and growth rates in diameter and height are parameters that have already been applied to several tropical tree species in order to analyze and understand the balance between, and the levels of, nutrients in the soil and in the plant [ 23 , 39 ]. In this context, the plant responses almost always suggest that their physiological performance is limited by P [ 9 , 40 ].…”