Chloroplastidic pigments, gas exchange, and carbohydrates changes during Carapa guianensis leaflet expansion

Abstract

Changes in chloroplastidic pigments, gas exchange and carbohydrate concentrations were assessed during the rapid initial expansion of C. guianensis leaflet. Leaves at metaphyll stage were tagged and assessments were carried out 14, 17, 20, 23, 27, and 31 days later. Pigments synthesis, distribution and accumulation were uniform among leaflet sections (basal, median and apical). Chlorophyll (Chl) a, Chl b, Chl (a+b), and total carotenoids (Car) concentrations were significantly increased after 27 days from metaphyll, and the most expressive increases were parallel to lower specific leaflet area. Chl a/b was lower on day 14 and it was increased on subsequent days. Negative net photosynthesis rate (P N ), and the lowest stomatal conductance (g s ) and transpiration (E) were registered on day 14, following significant increases on subsequent days. The Chl (a+b) and Chl a effects on P N were more expressive until day 20. Intercellular to ambient CO 2 concentration ratio (C i /C a ) was higher on day 14 and lower on subsequent days, and no stomatal limitation to CO 2 influx inside leaflets was observed. Leaflet temperature was almost constant (ca. 35°C) during leaflet development. Sucrose and starch concentrations were increased in parallel to increases in P N . Altogether, these results highlight the main physiological changes during C. guianensis leaflet expansion and they should be considered in future experiments focusing on factors affecting P N in this species.

Research on the adaptive mechanism of photosynthetic apparatus under salt stress: New directions to increase crop yield in saline soils

“…Chl a is the most important pigment involved in the capture of light and the storage and transfer of energy along the photochemical pathway, while Chl b shows an accessory function in photosynthesis and it is synthesised from Chl a . The lower Chl a/b ratio is indicative that photosystems may not be fully structured to maximise light capture and energy transfer during the stress (Moraes, Castro, Júnior, Pinheiro, & Festucci‐Buselli, ). Additionally, a decrease in the Chl a / b ratio may demonstrate a shift in the PSII/PSI ratio and/or modification in the antennae composition (Barhoumi et al, ; Váradi, Polyánka, Darkó, & Lehoczki, ).…”

Ultrasound-assisted lipid extractions, enriched with sterols and tetranortriterpenoids, fromCarapa guianensisseeds and the application of lipidomics using GC/MS

“…Initially, it seems that the solvents do not present relevant extractions influence, although when pyridine was used to improve the methanol extraction its influences in the derivatization of all polar molecules present in the G3-P (methanolic extract with pyridine) extract, including sugars, and micro phenolic molecules, Table 4 . This addition takes out all limonoids and steroids present but also takes out all molecules not desired like sugars and phenolic acids hydrolyzed from cell walls or that are present in the growth cell as described by Lima et al 43 and Moraes et al 44 The detection and analysis of these polar molecules may be related to the solubility of these substances in solvents of medium and high polarity and associated with the exposure of the ultrasonic bath that turns polar molecules more easily extracted. Some compounds could not be identified due to the lack of mass spectrum pattern.…”

Exogenous glycine betaine modulates ascorbate peroxidase and catalase activities and prevent lipid peroxidation in mild water-stressed Carapa guianensis plants

“…Leaf gas exchange: P N , stomatal conductance to water vapor (g s ), and intercellular to ambient CO 2 concentration ratio (C i /C a ) were measured using a portable open-system infrared gas analyzer (LCpro, ADC Bioscientific Ltd., Hoddesdon, UK) under ambient CO 2 concentration as described in Moraes et al (2011). During measurements, the mean air temperature, relative air humidity, and PAR at midday were 34°C, 90%, and 1,044.39 µmol(photon) m -2 s -1 , respectively.…”