Changes of carbon and nitrogen metabolites in white spruce (Picea glauca [Moench] Voss) of contrasted growth phenotypes

Abstract

The present study documents the changes occurring at the biochemical level in white spruce trees (Picea glauca [Moench] Voss) with contrasted growth phenotypes during the summer period. Full-siblings of tall versus small spruces were grown under controlled conditions at constant day/night temperatures (24/15°C) and exposed to a decreasing photoperiod (15.7-12.2 h) simulating natural photoperiod reduction during the summer in eastern Canada. Growth parameters (stem height and tree biomass) were determined and non structural carbohydrates, soluble proteins and amino acids were quantified in current-year needles and stem, oldest stem and roots from mid-July until the end of September 2006. Sucrose was the main soluble sugar found in all organs, but its concentrations did not significantly change during the summer. In contrast, starch concentrations rapidly declined by the end of the experiment, especially in needles and stems. Both sucrose and starch did not generally differ between growth phenotypes. Total soluble protein significantly accumulated by mid-August (14.4 h of photoperiod) in small trees. Arginine and glutamine were the most abundant amino acids found in spruce organs, and their concentrations strongly increased at 14.4 h of photoperiod, especially in small trees. Our results highlight marked differences in nitrogen metabolism in late summer between contrasted growth phenotypes, especially for arginine, an amino acid typically associated with growth arrest and nitrogen reserve in perennial species. They also reveal that old stems and roots are important storage organs of organic reserves.

Photosynthetic carbon and nitrogen metabolism and the relationship between their metabolites and lipid peroxidation in dwarf bamboo (Fargesia rufa Yi) during drought and subsequent recovery

“…8), which suggests that dwarf bamboo could withstand the drought of a certain intensity and duration. Furthermore, some studies showed that many osmoprotectants involved in C and N metabolism play a key role in scavenging or detoxifying ROS and reducing membrane lipid peroxidation (Couée et al 2006;Dhont et al 2011;Upadhyaya et al 2013). Our research found that a notable positive correlation between MDA and the contents of starch and proline after 15 days drought, and the contents of soluble sugar, NSC as well as proline after 30 days drought (P \ 0.05) ( Table 4), inferring that dwarf bamboo could employ different metabolites involved in C and N metabolism with different duration of drought to protect against membrane lipid peroxidation.…”

“…Unfortunately, overproduction of ROS is known to cause membrane lipid peroxidation and seriously damage plants (Upadhyaya et al 2008). Meanwhile, besides enzymatic and non-enzymatic antioxidative defense systems, many osmoprotectants involved in C and N metabolism are important in scavenging or detoxifying ROS and reducing lipid peroxidation (Couée et al 2006;Dhont et al 2011;Upadhyaya et al 2013). Recently, sugars have been proposed as emerging antioxidants in plants and might scavenge hydroxyl and superoxide radicals (Couée et al 2006).…”

Effect of exponential fertilization on growth and nutritional status in Buddhist pine (Podocarpus macrophyllus[Thunb.] D. Don) seedlings cultured in natural and prolonged photoperiods

“…Additionally, Dhont et al (2011) reported dynamic changes of needle N sources in the form of free amino acids and soluble proteins in small Picea glauca [Moench] Voss trees in response to decreasing photoperiod. In our study, the interaction of photoperiod and EF was significant for needle N concentration and content in Buddhist pine seedlings, and EF positively promoted N to be concentrated in needles in EP (Table 3).…”

effect of warming and water deficit on the non-structural sugars varations in picea mariana /

“…Xylem and cambium had a mean of total NSC of 1.61 mg/gdw and 24.62 mg/gd W respectively from May to September, the demand in energy of growing cells of cambium explaining here the larger amount of carbohydrates then in the xylem, a mostly non active part if the stem. In contrast, needles of white spruce contained about 32 mg/gdw while the entire stem contained about 21 mg/gd W of soluble sugars from mid-July to the end of September (Dhont et al, 2011). However, stems are known to have lower amount of carbohydrates than branches and leaves (Hoch et al, 2003).…”