End: mar 2023
Start: jan 2019
This project aims to improve the quality of Norwegian wheat used for milling to secure high and stable production in forthcoming decades under more challenging climatic conditions. Increasing wheat production for milling is the most efficient way to achieve increased domestic food production in Norway and it will strengthen the competitiveness in the agricultural sector.
|External project link||Project website at Cristin|
|Start - end date||01.01.2019 - 31.03.2023|
|Project manager||Anne Kjersti Uhlen (NOFIMA)|
The milling and baking industry requires wheat with high protein content and stable and good gluten quality to meet the two of the main quality criteria of wheat for processing. Previous R&D performed in close cooperation with the value chain, has contributed successfully to increased Norwegian wheat production from insignificant levels in 1970 up to 70% of the domestic demand in mid 2000’s. In the last decade, however, the quality of Norwegian wheat has varied considerably, and this variation has been linked to more challenging weather conditions for production. The project aims to increase Norwegian wheat quality to achieve better utilization of Norwegian wheat, and thus meet the national goals of increased food production.
The MATHVETE project aims to develop knowledge and new adaptation strategies in the value chain to ensure high production of Norwegian bread wheat with stable and good baking quality in a future challenging climate. The project is led by Nofima, in collaboration with NIBIO, NMBU, Graminor and the partners from the grain industry. NIBIO participates in two work packages.
NIBIO is involved in work where the effect of biotic and abiotic factors on gluten quality in wheat will be investigated. Wheat will be cultivated in climate controlled growth chambers and inoculated with fungal pathogens followed by irrigation regimes in order to simulate field conditions giving reduced baking quality. NIBIO will, in collaboration with Nofima, investigate and document whether isolates of Fusarium spp., and Microdochium spp., can degrade gluten in an in vitro-system, and further study the influence on gluten quality in wheat after infection with these fungal species.
When a high level of wheat yield is achieved, it may be demanding to obtain a high protein content in the grain. The high yield level often leads to a dilution effect on the protein content, and an adapted nitrogen fertilization strategy is required, so that the plants are able to reach a protein content high enough to meet the industry standards. In field trials, NIBIO will study the relationship between late split fertilization and protein development in wheat. We will monitor plant growth and reaction to different fertilizer rates throughout the summer by using various sensors. The late split fertilization will be carried out at the well-established time for late fertilization (beginning of the heading stage) and later, at full flowering. The results from the field trials will be used to develop an empirical model for estimating yield and protein content during the season.
Publications in the project
The bread-making quality of wheat depends on the viscoelastic properties of the dough in which gluten proteins play an important role. The quality of gluten proteins is influenced by the genetics of the different wheat varieties and environmental factors. Occasionally, a near complete loss of gluten strength, measured as the maximum resistance towards stretching (Rmax), is observed in grain lots of Norwegian wheat. It is hypothesized that the loss of gluten quality is caused by degradation of gluten proteins by fungal proteases. To identify fungi associated with loss of gluten strength, samples from a selection of wheat grain lots with weak gluten (n = 10, Rmax < 0.3 N) and strong gluten (n = 10, Rmax ≥ 0.6 N) was analyzed for the abundance of fungal operational taxonomic units (OTUs) using DNA metabarcoding of the nuclear ribosomal Internal Transcribed Spacer (ITS) region ITS1. The DNA quantities for a selection of fungal pathogens of wheat, and the total amount of fungal DNA, were analyzed by quantitative PCR (qPCR). The mean level of total fungal DNA was higher in grain samples with weak gluten compared to grain samples with strong gluten. Heightened quantities of DNA from fungi within the Fusarium Head Blight (FHB) complex, i.e. Fusarium avenaceum, Fusarium graminearum, Microdochium majus, and Microdochium nivale, were observed in grain samples with weak gluten compared to those with strong gluten. Microdochium majus was the dominant fungus in the samples with weak gluten. Stepwise regression modeling based on different wheat quality parameters, qPCR data, and the 35 most common OTUs revealed a significant negative association between gluten strength and three OTUs, of which the OTU identified as M. majus was the most abundant. The same analysis also revealed a significant negative relationship between gluten strength and F. avenaceum detected by qPCR, although the DNA levels of this fungus were low compared to those of M. majus. In vitro growth rate studies of a selection of FHB species showed that all the tested isolates were able to grow with gluten as a sole nitrogen source. In addition, proteins secreted by these fungi in liquid cultures were able to hydrolyze gluten substrate proteins in zymograms, confirming their capacity to secrete gluten-degrading proteases. The identification of fungi with potential to influence gluten quality can enable the development of strategies to minimize future problems with gluten strength in food-grade wheat.
This study aims to understand the environmental factors, focusing on rain and fungal infection, affecting the assembly of glutenin polymers during grain maturation. Spring wheat was grown in the field and grains were sampled from 50% grain moisture until maturity. Grain moisture content, protein content, size of glutenin polymers, the presence of proteases, and the amount of DNA from common wheat pathogenic fungi were analysed. Rain influenced the rate of grain desiccation that occurred parallel to the rate of glutenin polymer assembly. Rapid desiccation contributed to faster glutenin polymer assembly than gradual desiccation. Severe reduction in the glutenin polymer size coincided with increased grain moisture due to rain. Furthermore, increased fungal DNA followed by presence of gluten-degrading proteases was observed in the grain after humid conditions. The presence of gluten-degrading proteases was presumably involved in reducing the size of glutenin polymers in grain. Our study gave new insight into how environmental conditions could be associated with the assembly of glutenin polymers during grain maturation. The results suggest that rain and/or fungal proteases play an important role in reducing the molecular size of glutenin polymers.