Zn-biofortification enhanced nitrogen metabolism and photorespiration process in green leafy vegetable Lactuca sativa L

Abstract BACKGROUND: Excessive rates of nitrogen (N) fertilizers may result in elevated concentrations of nitrate (NO3 −) in plants. Considering thatmany programs of biofortification with trace elements are being performed, it has become important to study how the application of these elements affects plant physiology and, particularly, N utilization in leaf crops. The main objective of the present study was to determine whether the NO3 − accumulation and the nitrogen use efficiency was affected by the application of different doses of Zn in Lactuca sativa plants. RESULTS: Zn doses in the range 80–100 mol L−1 produced an increase in Zn concentration provoking a decrease of NO3 − concentration and increase of the nitrate reductase, glutamine synthetase and aspartate aminotransferase activities, as well as the photorespiration processes. As result, we observed an increase in reduced N, total N concentration and N utilization efficiency. Consequently, at a dose of 80 mol L−1 of Zn, the amino acid concentration increased significantly. CONCLUSION: Adequate Zn fertilization is an important critical player in lettuce, especially at a dose of 80 mol L−1 of Zn, because it could result in an increase in the Zn concentration, a reduction of NO3 − levels and an increase the concentration of essential amino acids, with all of them having beneficial properties for the human diet

Evaluation of hydrogen sulfide supply to biostimulate the nutritive and phytochemical quality and the antioxidant capacity of Cabbage (<i>Brassica oleracea</i> L. ‘Bronco’)

The potential effects of the hydrogen sulfide on shoot biomass, nutritional quality and antioxidant capacity of Brassica oleracea, were investigated through the application of increasing doses of NaHS (H2S donor NaHS; 0.5, 1, 2.5, and 5 mM). The results showed that the 0.5 and 1 mM NaHS treatments increased biomass and the quality composition of ‘Bronco’ cabbage (i.e. chlorophylls, carotenoids, anthocyanins, flavonols, total phenolics and sinigrin). On the other hand, there was an increase in lipid peroxidation and hydrogen peroxide content with the application of doses higher than 2.5 mM NaHS. Therefore, we selected the 0.5 and 1 mM NaHS dosages as optimal for cabbage. The 2.5 and 5 mM NaHS produced an excessive lipid peroxidation, decreases in plant biomass and losses of chlorophylls, being all considered negative effects, and clear evidences of stressful situation for the plants. For practical purposes, this study suggested that exogenous application of H2S donor NaHS at 0.5 and 1 mM may be useful as bio-stimulant to boost the yield and the health-promoting composition of ‘Bronco’ cabbage (Brassica oleracea L.).   The online version of theis article (doi: 10.5073/JABFQ.2016.089.038) contains a supplementary file

Estudio de diferentes aspectos agronómicos y fisiológicos del zinc en plantas hortícolas: Fitoextracción y biofortificación

Esta tesis trata de hacer un estudio de las diferentes estrategias en plantas de Lactuca sativa y Brassica oleracea ante la toxicidad de Zn (0.5 mM), tales como el metabolismo de los carboxilatos y el metabolismo oxidativo y del glutatión así como utilizar estas plantas hortícolas en programas de descontaminación (fitoextracción) en aquellas zonas contaminadas por este elemento traza.Tesis Univ. Granada. Programa Oficial de Doctorado en: Biología Fundamental y de SistemasGrupo de Investigación ``Diagnóstico Nutricional de las Plantas Cultivadas en Condiciones Adversas´´ (AGR-161, Plan Andaluz de Investigación, Junta de Andalucía

Comparative study of Zn deficiency in L. sativa and B. oleracea plants: NH4+ assimilation and nitrogen derived protective compounds

This work was financed by the PAI program (Plan Andaluz de Investigación, Grupo de Investigación AGR161) and by a Grant from the FPU of the Ministerio de Educación y Ciencia awarded to ENL.Zinc (Zn) deficiency is a major problem in agricultural crops of many world regions. N metabolism plays an essential role in plants and changes in their availability and their metabolism could seriously affect crop productivity. The main objective of the present work was to perform a comparative analysis of different strategies against Zn deficiency between two plant species of great agronomic interest such as Lactuca sativa cv. Phillipus and Brassica oleracea cv. Bronco. For this, both species were grown in hydroponic culture with different Zn doses: 10 µM Zn as control and 0.01 µM Zn as deficiency treatment. Zn deficiency treatment decreased foliar Zn concentration, although in greater extent in B. oleracea plants, and caused similar biomass reduction in both species. Zn deficiency negatively affected NO3- reduction and NH4+ assimilation and enhanced photorespiration in both species. Pro and GB concentrations were reduced in L. sativa but they were increased in B. oleracea. Finally, the AAs profile changed in both species, highlighting a great increase in glycine (Gly) concentration in L. sativa plants. We conclude that L. sativa would be more suitable than B. oleracea for growing in soils with low availability of Zn since it is able to accumulate a higher Zn concentration in leaves with similar biomass reduction. However, B. oleracea is able to accumulate N derived protective compounds to cope with Zn deficiency stress.Plan Andaluz de Investigación AGR161Ministerio de Educación y Cienci

Zinc biofortification improves phytochemicals and amino-acidic profile in Brassica oleracea cv. Bronco

Zn deficiency is currently listed as a major risk factor for human health. Recently, a complimentary solution to mineral malnutrition termed 'biofortification' has been proposed. The aim of this study was to investigate the possible effects of a Zn-biofortification program on Zn levels, amino acidic profile and the phytochemicals content in an edible leafy vegetable, such as Brassica oleracea cv. Bronco. Our results indicate that supplementation of 80-100μM Zn is optimal for maintaining the normal growth of plants and to promote the major Zn concentration in the edible part of B. oleracea. Any further increase of Zn supply induced an accumulation of total amino acids, and increased the enzymatic activities involved in sulfur assimilation and synthesis of phenols, finally resulting in a foliar accumulation of glucosinolates and phenolic compounds. Thus, it could be proposed that the growth of B. oleracea under 80-100μM Zn may increase the intake of this micronutrient and other beneficial compunds for the human health