Drought stress affects the protein and dietary fiber content of wholemeal wheat flour in wheat/Aegilops addition lines

Abstract

Wild relatives of wheat, such as Aegilops spp. are potential sources of genes conferring tolerance to drought stress. As drought stress affects seed composition, the main goal of the present study was to determine the effects of drought stress on the content and composition of the grain storage protein (gliadin (Gli), glutenin (Glu), unextractable polymeric proteins (UPP%) and dietary fiber (arabinoxylan, β-glucan) components of hexaploid bread wheat (T. aestivum) lines containing added chromosomes from Ae. biuncialis or Ae. geniculata. Both Aegilops parents have higher contents of protein and β-glucan and higher proportions of water-soluble arabinoxylans (determined as pentosans) than wheat when grown under both well-watered and drought stress conditions. In general, drought stress resulted in increased contents of protein and total pentosans in the addition lines, while the β-glucan content decreased in many of the addition lines. The differences found between the wheat/Aegilops addition lines and wheat parents under well-watered conditions were also manifested under drought stress conditions: Namely, elevated β-glucan content was found in addition lines containing chromosomes 5Ug, 7Ug and 7Mb, while chromosomes 1Ub and 1Mg affected the proportion of polymeric proteins (determined as Glu/Gli and UPP%, respectively) under both well-watered and drought stress conditions. Furthermore, the addition of chromosome 6Mg decreased the WE-pentosan content under both conditions. The grain composition of the Aegilops accessions was more stable under drought stress than that of wheat, and wheat lines with the added Aegilops chromosomes 2Mg and 5Mg also had more stable grain protein and pentosan contents. The negative effects of drought stress on both the physical and compositional properties of wheat were also reduced by the addition of these. These results suggest that the stability of the grain composition could be improved under drought stress conditions by the intraspecific hybridization of wheat with its wild relatives.

Identification of New QTLs for Dietary Fiber Content in Aegilops biuncialis

“…Grain β-glucan, TP, WEP, and protein content in Ae. biuncialis accessions and Mv9kr1 wheat line as determined in the present study were similar to those estimated earlier when the effect of added Aegilops chromosomes on the grain composition of wheat was analyzed [ 31 , 33 ]. Diversity analysis of 43 wild and cultivated diploid, tetraploid and hexaploid wheat accessions demonstrated that β-glucan is the dominant form of cell wall polysaccharides in Aegilops species with U and M genomes.…”

“…Ae. biuncialis grains have also been found to contain a significantly larger amount of micronutrients [ 30 ], edible fiber, and protein [ 31 , 32 , 33 ] compared to bread wheat. To introduce favorable agronomic traits of Aegilops , some U b - and M b -genome chromosomes were transferred into wheat by the development of wheat- Ae.…”

Applying Biostimulants to Combat Water Deficit in Crop Plants: Research and Debate

“…It is well-known that drought stress causes changes in cereal grain composition, such as an important decrease in carbohydrate accumulation and an increment in protein content [49,50]. However, our results show a decrease in both parameters (Figure 4).…”

Breeding Driven Enrichment of Genetic Variation for Key Yield Components and Grain Starch Content Under Drought Stress in Winter Wheat

“…The decrease of GPC detected in our study may be due to the application of drought at very early stage of plant development. Indeed, it has been reported that the effect of drought stress on grain quality highly depends on its intensity and when it occurs (Rakszegi et al, 2019). Larger phenotypic variations were observed among the wheat cultivars under drought stress when compared to the rainfed conditions as indicated by higher CV and more dispersed scatter points across regression lines.…”