Nitrogen-improved photosynthesis quantum yield is driven by increased thylakoid density, enhancing green light absorption. (January 2019)

• Record Type: Journal Article
• Authors: Moriwaki, Thaise; Falcioni, Renan; Tanaka, Francisco André Ossamu; Cardoso, Kátia Aparecida Kern; Souza, L.A.; Benedito, Evanilde; Nanni, Marcos Rafael; Bonato, Carlos Moacir; Antunes, Werner Camargos
• Is Part Of: Plant science. Volume 278(2019)
• Page Start: 1
• Page End: 11
• Publication Date: 2019-01
• Subjects: A absorbance -- A net carbon assimilation rate -- ATP adenosine triphosphate -- C carbon -- Car carotenoids -- Chl chlorophyll -- Chla chlorophyll a -- Chlb chlorophyll b -- Chla+b chlorophyll a+b -- Ci intercellular CO2 concentration -- CO2 carbon dioxide -- DW dry weight -- gs stomatal conductance -- IRGA infrared gas analyzer -- LA leaf area -- LM leaf mass -- LMF leaf mass fraction -- N nitrogen -- NADPH nicotinamide adenine dinucleotide phosphate -- NH4+-N ammoniacal N -- NO3--N nitric N -- PAR photosynthetically active radiation -- PC1 principal component 1 -- PC2 principal component 2 -- PCA principal component analysis -- Pcomp light compensation point -- Psat light saturation point -- R reflectance -- Rd respiration rates in dark -- RGR relative growth rate -- RMF root mass fraction -- RuBisCO ribulose-1, 5-bisphosphate carboxylase/oxygenase -- RuBP ribulose-1, 5-bisphosphate -- SLA specific leaf area -- SMF stem mass fraction -- T transmittance -- ULR unit leaf rate -- α maximum photosynthetic quantum yield; Light absorbance -- Quantum yield -- Photosynthesis -- Chloroplasts -- Thylakoids -- Plant growth; Botany -- Periodicals; Botanique -- Périodiques; 580
• DOI: 10.1016/j.plantsci.2018.10.012
• Languages: English
• ISSNs: 0168-9452

Abstract

Highlights: The reasons why N stimulates tomato plants dry weight accumulation were revisited under high and low light. High chlorophyll content in leaves improves green light absorption, not blue or red. Enhanced green light absorbance is the primary component that drive increased plant growth under natural light-limited photosynthesis. Ultrastructurally, this was associated to a high number of granum per chloroplast and greater thylakoid stacking under high N supplies. Abstract: A nitrogen supply is necessary for all plants. The multifaceted reasons why this nutrient stimulates plant dry weight accumulation are assessed herein. We compared tomato plants grown in full sunlight and in low light environments under four N doses and evaluated plant growth, photosynthetic and calorimetric parameters, leaf anatomy, chloroplast transmission electron microscopy (TEM) and a high resolution profile of optical leaf properties. Increases in N supplies allow tomato plants to grow faster in low light environments (91.5% shading), displaying a robust light harvesting machinery and, consequently, improved light harvesting efficiency. Ultrastructurally, high N doses were associated to a high number of grana per chloroplast and greater thylakoid stacking, as well as high electrodensity by TEM. Robust photosynthetic machinery improves green light absorption, but not blue or red. In addition, low construction and dark respiration costs were related to improved total dry weight accumulation in shade conditions. By applying multivariate analyses, we conclude that improved green light absorbance, improved quantum yield and greater palisade parenchyma cell area are the primary components that drive increased plant growth under natural light-limited photosynthesis.