Background: Zinc (Zn) is an important nutrient for human beings, which is also an essential micronutrient for crop growth. This study investigated the role of Zn in coordinating the mineral elements absorption in modern wheat (Triticum aestivum L.) cultivars with a new developed method. Results: A method was developed, and showed a robust capability to simultaneously investigate seven mineral elements uptake in wheat seedling. With this method, we found low Zn supply (< 1 μM) promoted the absorption of potassium (K), magnesium (Mg) and manganese (Mn) in wheat seedling, while high Zn supply (> 1 μM) significantly inhibited the absorption of these elements. Cultivars with the green genes (Rht-B1b and Rht-D1b) showed a higher uptake capability on ammonium (NH4+), and cultivars with Rht-B1b allele can uptake more phosphors (P), K, calcium (Ca), Mn and Zn compared to cultivars with Rht-D1b. Further analysis indicated higher uptake capability of NH4+ in cultivars contained Rhts was independent of Zn. Conclusion: The key role of Zn in coordinating for mineral elements absorption was identified in modern wheat cultivars, providing the reference for Zn application in wheat. Meanwhile, this study provides a robust method for quantifying the absorption of mineral elements, which may be adopted into the broadly investigations on the coordinated nutrients absorption of plant.
Powdery mildew is a key airborne foliar disease of barley in southeastern and southwestern China. Barley varieties usually partially or wholly lose resistance to the pathogen Blumeria graminis (DC.) f. sp. hordei 3 to 5 years after release due to the frequent acquirements of new virulences in the pathogen population. However, no B. graminis f. sp. hordei virulence detection has been carried out in the recent decade and, thus, no information is available on the present virulence components and major pathotypes in epidemic regions. Twenty-one near-isogenic lines of Pallas were selected to detect B. graminis f. sp. hordei virulence variation, with 97 pathotypes identified from the isolates collected from 2015 to 2019. The virulence complexities ranged from 1 to 12, with 1.5 isolates on average assigned per pathotype, suggesting a natural trait of high pathotype diversity and low virulence complexity in the Chinese B. graminis f. sp. hordei populations. Eleven high-virulence pathotypes were detected in the traditional barley-growing regions in Yunnan and Zhejiang. Six virulent pathotypes to resistance gene mlo-5 were detected only in the two traditional epidemic regions, with a virulence frequency (VF) of 4.8% (7 of 147). Compared with the results from a decade ago, VFs for resistance alleles Mla3, mlo-5, Mla6 + Mla14, Mla7 + Mlk, Mlg + MlCP, and Mla13 + MlRu3 + MlaRu4 increased from 0 to 0.7 to 25.8%. Isolates from Yunnan and Zhejiang had similar virulence profiles, which differed from those identified in Tibet. In addition, genetic diversities differed in the isolate groups collected from Tibet, Yunnan, and Zhejiang.
Pasting properties are important characteristics of barley starch from a processing standpoint. Many studies reported the close relationship between pasting properties and malting quality, especially malt extract. However, most conclusions were derived from the correlation between pasting properties and malting quality using a set of cultivars or breeding lines. In this study, a doubled haploid population of 150 lines from a cross between a Japanese malting barley and a Chinese feed barley was grown in four different environments (two sites × two years). Based on average values from all different environments, 17 significant quantitative trait loci (QTL) were identified for pasting properties. The genetic variance explained by these QTL varied from 7.0 to 23.2%. Most QTL controlling pasting properties were located on 1H, 2H, 5H, and 7H. Results confirmed the linkage between pasting properties and malt extract, with most of the QTL for pasting properties becoming nonsignificant when using malt extract as a covariate. Breakdown showed the closest correlation with malt extract. Molecular markers closely linked to the QTL can be used to select desired pasting properties to improve malting quality.
Resistant starch (RS) shows several health benefits. Enhancing the RS content of wheat is of major commercial importance. However, knowledge regarding the RS synthesis mechanism in wheat remains limited. In this study, the dynamic accumulation of RS during the filling process in two wheat (Triticum aestivum L.) genotypes with contrasting RS contents (H242, high RS content; H189, low RS content) were investigated. The results demonstrate that beyond 25 days after pollination (DAP), the RS content of H189 was relatively stable, but that of H242 continued to increase. Secondary accumulation was observed in the high-RS-content wheat genotype. A comparative transcriptome analysis between H242 and H189 at 20 DAP and 35 DAP showed that the differentially expressed genes were mainly involved in glycerolipid metabolism, glycerophospholipid metabolism and glucuronate interconversions. Furthermore, weighted gene coexpression network analysis suggested that lipid metabolic pathways such as the glycerophospholipid metabolism pathway might be involved in RS synthesis, and lipid-related genes upregulated beyond 25 DAP resulted in RS secondary accumulation. This work provides insight into the characteristics and mechanisms of RS synthesis.