Photosynthetic and Antioxidant Performance Are Differentially Affected by Short-Term Nitrogen Supply in Highbush Blueberry Cultivars at the Short-Term

Abstract

E. Yañez-Mansilla, P. Cartes, M. Reyes-Díaz, A. Ribera-Fonseca, and M. Alberdi. 2014. Photosynthetic and antioxidant performance are differentially affected by short-term nitrogen supply in highbush blueberry cultivars. Cien. Inv. Agr. 41(1): 61-70. Nitrogen (N) is an essential nutrient for photosynthesis and may influence phenolic compound synthesis in higher plants. The effect of different amounts of N (0 to 38 mM) provided on a short-term (4 d) basis on the photosynthetic and antioxidant performance of highbush blueberry cultivars (Legacy and Bluegold) grown in a nutrient solution was studied. In both cultivars, the N concentration of leaves slightly increased in response to the N supply, with Bluegold frequently showing higher N concentrations than Legacy. Photosynthesis was reduced in Bluegold at the highest N dose, whereas in Legacy, a decrease of CO 2 assimilation occurred under N starvation. This decrease in photosynthesis was accompanied by enhanced lipid peroxidation but only in Bluegold. In both cultivars superoxide dismutase (SOD) was activated with an increasing N supply. Legacy also showed increased SOD activity to counteract oxidative stress at higher N levels. Radical scavenging activity was not affected by the N supply. However, the total phenols and anthocyanins steadily declined in the leaves of Legacy, and flavonoids were significantly increased in the roots of both cultivars with increasing N treatments. Thus, our findings indicate that blueberry cultivars exhibit differential sensitivity to short-term N stress, and SOD appears to be more involved than phenolic compounds in the amelioration of N-induced oxidative stress. Further studies are required to confirm the sensitivity to either N starvation in Legacy or N excess in Bluegold under long-term conditions.

Nitrogen Enhances Salt Tolerance by Modulating the Antioxidant Defense System and Osmoregulation Substance Content in Gossypium hirsutum

“…The elimination of H 2 O 2 might be due to the immediate strengthening of SOD, CAT, and POD activities (Figure 8), and the increased content of free amino acids (Figure 5E,F) by higher nitrogen application. Moreover, in support of the outcomes of the present study, several other scholars reported that co-application of nitrogen significantly boosted the level of antioxidant enzymes in soybean [56], Catharanthus roseus [57], and blueberry [58]. Nitrogen serves as a first line of defense against internal and environmental oxidative stressors [17,21,59,60].…”

Leaf nitrogen thresholds ensuring high antioxidant features of Vaccinium corymbosum cultivars

“…Despite that in previous results we observed a differential response on physiological and antioxidant parameters to N fertilization during 4 days (Yañez-Mansilla et al, 2014), there are not studies about N concentration in leaves that maintain a high antioxidant performance in blueberries at the long-term. We hypothesized that there is N concentration threshold that ensure a high phenolic concentration and antioxidant capacity without detrimental effects on plant performance.…”

“…Later on, plants were grown under the following N treatments: 0, 9, 18, 28 or 38 mM N. The N treatments were applied based on differential NH 4 NO 3 levels in the culture media, and they were chosen in order to exceed the N sufficiency level associated with adequate photosynthetic performance and plant growth at the short-term (Yañez-Mansilla et al, 2014). Nutrient solutions were replaced every 7 days and aerated during the course of experiment with an aquarium pump.…”

Changes in the antioxidant and glyoxalase enzyme activities in leaves of two Moroccan sorghum ecotypes with differential tolerance to nitrogen stress

“…Many studies have reported that the leaf lipid peroxidation was increased under both N deficiency and N excess stress conditions. In fact, it was demonstrated that N deficiency increased MDA concentration in Vaccinium corymbosum (Yañez-Mansilla et al, 2014;Yañez-Mansilla et al, 2015). Similar increase of MDA was observed in Myriophyllum spicuatum and Potamogeton crispus leaves under ammonium stress (Jiao et al, 2009;Yin et al, 2016).…”

“…However, it is now well known that ammonium is toxic to many plant species, leading to a reduction in growth and alteration in content of amino acids, mineral cations and organic anions (Li et al, 2011). Only few studies about antioxidant responses in crop-plants grown under differential N supply have been conducted (Nimptsch and Pflugmacher, 2007;Yañez-Mansilla et al, 2014;Yañez-Mansilla et al, 2015). Asada and Takahashi (1987) reported that N excess is generally related to the accumulation of ammonium in plant tissues, whereas N deficiency may increase the production of ROS.…”