Aspects of nitrogen metabolism in coffee plants

Abstract

Coffee plants are highly N-demanding plants. Despite the importance of N nutrition for the development, acclimation and yield of coffee plants, there are few reports concerning N metabolism in this species. In this review, our intention is to summarize the information available in the literature and to point out the influence of environmental conditions on N assimilation, as well as comment and discuss some apparently contradictory results and raise and enlighten queries about N assimilation in coffee plants. Key words: Coffea, irradiance level, nitrate reductase, nitrogen fertilization, oxidative stress, photoinhbition, photoprotection, photosynthesis.Aspectos do metabolismo de nitrogênio em plantas de café: Plantas de cafédemandam grandes quantidades de N. Apesar da importância da nutrição nitrogenada para o desenvolvimento, aclimatação e produtividade de plantas de café, são poucos os trabalhos sobre o metabolismo de N nesta espécie. A intensão desta revisão é sumarizar a informação disponível na literatura e discutir a influência das condições ambientais na assimilação de N, assim como comentar e discutir alguns resultados aparentemente contraditórios e levantar e destacar perguntas sobre a assimilação de N em plantas de café. Palavras-chave: Coffea, estresse oxidativo, fertilização nitrogenada, fotoinibição, fotoproteção, fotossíntese, nível de irradiância, redutase do nitrato.Abbreviations -A, net photosynthetic rate; A max , photosynthetic capacity at CO 2 and light saturating conditions; C16:0, palmitic acid; C18:3, linolenic acid; 3 Car triplet state of β-carotene; chl, chlorophyll; 1 chl, singlet state of chl; 3 chl*, triplet state of chl; cyt, cytochrome; DEPS, de-epoxidation state; F o , minimal fluorescence of antennae in dark-adapted leaves; F v /F m and F v´/ F m´, photochemical efficiency of PSII in dark-adapted leaves and under photosynthetic steadystate conditions, respectively; H 2 O 2 , hydrogen peroxide; LHC, light harvesting complexes associated with photosystems; J max , electron transport capacity; NR, nitrate reductase; NRA, nitrate reductase activity; O 2•-, superoxide anion radical; 1 O 2 , singlet state of oxygen; OEC, oxygen-evolving complex from PSII; • OH, hydroxyl radical; P 680 , PSII reaction centre; PPFD, photosynthetic photon flux density; PSI and II, photosystem I and II, respectively; Q A , quinone A; q E , "high-energy" quenching; q NP , non-photochemical quenching; q P , photochemical quenching; TFA, total fatty acids; V cmax , maximum carboxylation activity; Φ, quantum yield of photosynthesis; φ e , estimation of the quantum yield of photosynthetic electron transport.

Effect of vermicompost tea on yield and nitrate reductase enzyme activity in saladette tomato

“…Our results coincide with those obtained by Crawford (1995) and Víllora et al (2002), who found that the NR enzymatic activity was modified by altering the concentrations of NO 3 -and Mo in the growth medium. The values of NR activity induced by simultaneous presence of NO 3 -and Mo showed the general need of plants for both NO 3 -and for Mo, to activate the enzyme and make use of cellular N. The presence of flowers and fruits in some plants accelerates and increases the endogenous NR activity (Carelli et al, 2006). At 105 DAP, NR activity produced higher induction of NO 3 -, Mo, and the combination of both factors, while endogenous NR activity diminished (Table 4).…”

Nutrient accumulation in bean and fruit from irrigated and non-irrigated Coffea canephora cv. Conilon

“…The retained nutrient amounts by coffee plants changes according to the location, time of year, age, organs and the tissues within the same plant (Bragança et al, 2007) and maturation cycle (Partelli et al, 2014). The coffee's fruiting process comprises a sequence of physiological events and morphological changes ranging from fl ower induction to fruit maturation, having a high demand for mineral nutrients (Carelli et al 2006;Bragança et al, 2007;Melo et al 2011;Partelli et al, 2014). During development, fruits are strong sinks for minerals and carbohydrates, therefore competing with other plant organs and often leading to nutritional defi ciencies in those organs of the same coffee plant (Reindeer and Maestri, 1985;Carvalho et al, 1993;Laviola et al, 2008).…”

Ecophysiology of coffee growth and production

“…Several aspects of coffee (eco)physiology have recently been reviewed, including water relations and drought tolerance (Carr, 2001;Rena, 2001, 2002a;DaMatta, 2004c;DaMatta and Ramalho, 2006), photosynthetic acclimation to light availability (DaMatta, 2004a), nitrogen metabolism (Carelli et al, 2006), seed physiology (Eira et al, 2006), caffeine (Baumann, 2006), and impacts of extreme temperatures and drought on coffee physiology and production (DaMatta and Ramalho, 2006). Therefore, these aspects will not be examined here in detail.…”