Leaf biochemical composition corresponds to traits related the plant state and its functioning. This study puts emphasis on main leaf absorbers: chlorophyll a b ( $$C_{ab}$$ ), carotenoids $$C_{c}$$ water $$C_{w}$$ ) dry mater $$C_{m}$$ contents. Two approaches were used estimate [ $$C_{ab} ,$$ , ] in non-destructive way using spectral measurements. The first one consists building empirical relationships from experimental datasets either raw reflectances or their combination into vegetation...

Sucrose:sucrose 6-fructosyltransferase, an enzyme activity recently identified in fructan-accumulating barley (Hordeum vulgare) leaves, was further characterized. The purified catalyzed the transfer of a fructosyl group from sucrose to various acceptors. It displayed some [beta]-fructosidase (invertase) activity, indicating that water could act as acceptor. Moreover, it transferred residue unlabeled [U-14C]Glc, producing [U-14C]sucrose and glucose. Most significantly for fructan synthesis,...

Abstract Wheat responses to F. graminearum result in a deep and sharp reprogramming of wide range biological processes, including energy‐associated functions related metabolisms. Although these impacts have been thoroughly described at the molecular scale through proteomics transcriptomics studies, phenotypic studies are still needed fill gap between observed events actual disease on ecophysiological processes. Taking advantage gas exchange method, effects two strains contrasting...

summary Mature blades of wheat seedlings were induced to form fructan by excision and continuous illumination, their sugars analyzed either 24 or 60 h after induction both gel permeation high performance liquid chromatography. The earliest accumulated consisted mainly 1‐kestose, nystose, bifurcose, short oligomers rich in (2→1)‐linkages branch point residues. After several days, included more than fifty compounds, among which one‐half the total heptamers larger. Oligomers during long‐term...

The simulation of phloem translocation by the Münch theory commonly uses resistances from sources to sinks: are therefore regarded as important in partitioning. Although resistance is generally a set constant, it fact strongly affected viscosity, and thus concentration transported solute. In this paper, model partitioning proposed Minchin et al. was first corrected for variations viscosity. further modified, with source considered an activity solute production rather than compartment...

French wheat grains may be of little value on world markets because they have low and highly variable grain protein concentrations (GPC). This nitrogen-yield to yield ratio depends crop nitrogen (N) fertilization as well capacity use N, which is known vary with climate disease severity. Here an examination made the respective roles that N remobilization post-anthesis uptake play in variations; particular, when crops (Triticum aestivum) are affected by leaf rust (Puccinia triticina) Septoria...

SUMMARY Two 2 m stands of wheat were grown under controlled conditions from d after anthesis until harvest. Day and night temperature 18 10 °C respectively in crop 1, whereas they shifted to 28 20 5 2. CO exchange rates the canopies continuously measured. Samples plants collected each two or three times a week. Grain filling was monitored as various carbohydrates enzyme activities stems. Sugar reserves highly correlated with difference between cumulative photosynthesis dry matter stored...

Experiments have shown that biotrophic fungi divert assimilates for their growth. However, no attempt has been made either to account this additional sink or predict what extent it competes with both grain filling and plant reserve metabolism carbon. Fungal competitiveness grains was quantified by a mixed experimental–modelling approach based on winter wheat infected Puccinia triticina. One week after anthesis, plants grown under controlled conditions were inoculated varying loads....

The accumulation of soluble carbohydrates was studied during chilling 2-week-old wheat (Triticum aestivum L.) seedlings. extracts were analysed using a C18 HPLC method separating hexoses, sucrose and wide range oligofructan. Isomers recognized their content determined. amounts the trisaccharides 1-kestose 6-kestose increased at beginning treatment. rate 1-kestose, trisaccharide generally considered to be precursor fructan, ten fold with some delay. Heavier fructan accumulated even later. In...

In plants, three-dimensional (3-D) organs such as inflorescences or fruits carry out photosynthesis and thus play a significant role in carbon assimilation yield. However, this contribution has been poorly characterized because there is no reliable method for measuring by 3-D organs. One of the major challenges ensuring uniform irradiation samples that are placed within sealed chamber.In study, we developed an innovative chamber with homogeneous lighting can be used to measure large It...

ABSTRACT Fusarium Head Blight (FHB) is a devastating fungal disease affecting cereals, caused by species that can produce harmful mycotoxins. share the same ecological niche, and their population dynamic associated mycotoxin patterns are driven environment. The aim of present study was to investigate ecophysiological characteristics major causing FHB under abiotic factors. Growth production different strains avenaceum, graminearum , langsethiae, poae tricinctum were characterized combined...

SUMMARY Fructosyltransferase activities were studied with varying concentrations of sucrose in cell‐free extracts from wheat ( Triticum aestivum L.). A C 18 ‐HPLC separation method was used to quantify the synthesized compounds individually. Hexoses and 1‐kestose major products at all temperatures sucrose. 1‐Kestose production maximal 25 °C, an apparent K m about 250 m, but competition for by invertase affected this value. Neokestose, which is not observed vitro , 6‐kestose also formed a...