Photochemistry and Antioxidative Capacity of Female and Male Taxus baccata L. Acclimated to Different Nutritional Environments

Abstract

In dioecious woody plants, females often make a greater reproductive effort than male individuals at the cost of lower growth rate. We hypothesized that a greater reproductive effort of female compared with male Taxus baccata individuals would be associated with lower female photochemical capacity and higher activity of antioxidant enzymes. Differences between the genders would change seasonally and would be more remarkable under nutrient deficiency. Electron transport rate (ETRmax), saturation photosynthetic photon flux corresponding to maximum electron transport rate (PPFsat), quantum yield of PSII photochemistry at PPFsat (ΦPPFsat), and chlorophyll a fluorescence and activity of antioxidant enzymes were determined in needles of T. baccata female and male individuals growing in the experiment with or without fertilization. The effects of seasonal changes and fertilization treatment on photochemical parameters, photosynthetic pigments concentration, and antioxidant enzymes were more pronounced than the effects of between-sexes differences in reproductive efforts. Results showed that photosynthetic capacity expressed as ETRmax and ΦPPFsat and photosynthetic pigments concentrations decreased and non-photochemical quenching of fluorescence (NPQ) increased under nutrient deficiency. Fertilized individuals were less sensitive to photoinhibition than non-fertilized ones. T. baccata female and male individuals did not differ in photochemical capacity, but females showed higher maximum quantum yield of PSII photochemistry (Fv/Fm) than males. The activity of guaiacol peroxidase (POX) was also higher in female than in male needles. We concluded that larger T. baccata female reproductive effort compared with males was not at the cost of photochemical capacity, but to some extent it could be due to between-sexes differences in ability to protect the photosynthetic apparatus against photoinhibition with antioxidants.

Sexual Dimorphism in the Chemical Composition of Male and Female in the Dioecious Tree, Juniperus communis L., Growing under Different Nutritional Conditions

“…As a consequence, males can use a greater amount of resources available for vegetative growth than females [17]. In regards to J. communis, however, it is important to note that female cones are able to photosynthesize as it was observed in Taxus baccata L. green arils [19] and they compensate at least a part of their production costs [20].…”

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

“…The increased tolerance to dry periods found under fertilization in some species in the present study may be related to the increased electron transport and photochemical efficiency and photoinhibition relief [ 20 , 61 ]. Plants may respond to fertilization treatments with increased plant performance and photosynthesis due to the importance of nutrients in physiological processes [ 54 , 62 ].…”

“…Through adjusting the N concentration, gas exchange and growth, N-fixers may take up and use resources efficiently, particularly in nutrient-limited soils [ 54 , 63 ]. The diminished electron transport reported under nutrient deficiencies may be partially due to the overreduction of the PSII acceptor side [ 61 ]. Multiple nutrient deficiencies reduce the slope of the OJIP curves in most species due to reduced ATP production under K and P deficiencies [ 15 , 64 ].…”

Effects of seasonality, fertilization and species on the chlorophyllafluorescence as related with photosynthesis and leguminous tree growth during Amazonian forest restoration

“…species may reflect improved recovery on the PSII acceptor side. The diminished electron transport reported under nutrient-poor conditions may be partially due to the overreduction of the PSII acceptor side (51).…”