The plant cell wall is dynamically modified during host–pathogen interactions and acts as a crucial factor controlling plant immunity. In the context of recently revised models of plant primary cell walls (PCWs), pectin is considered to be important in determining the mechanical properties of PCWs. A secondary cell wall is present in some cell types and lignin is normally present and acts to strengthen wall rigidity. In this review, we summarize the recent advances in understanding cell-wall-mediated defense responses against pathogens in Brassica napus L. (B. napus). A major part of this response involves pectin and lignin, and these two major cell wall components contribute greatly to immune responses in B. napus. Crosstalk between pectin and lignin metabolism has been detected in B. napus upon pathogen infection, suggesting a synergistic action of pectin and lignin metabolism in regulating cell wall integrity as well as wall-mediated immunity. The transcriptional regulation of cell-wall-mediated immunity in B. napus along with that in Arabidopsis is discussed, and directions for future work are proposed for a better understanding of wall-mediated plant immunity in B. napus.
Additional file 3: Table S3. Genotyping of the dKASP markers for plant height, grain hardness, and high-molecular-weight glutenin in 518 F5 lines from the breeding program. A, B, C, and D correspond to the genotypes in Table 1.
Grain hardness has important effects on grain quality and the end-use of wheat. In this study, a collection of 103 common wheat germplasms and a DH population of 194 lines were used to identify new quantitative trait loci (QTL) for grain hardness. Two stable genetic loci on chromosome 5D were detected under different locations and years with one of them being the Ha locus on 5DS where the major gene Puroindolines for wheat grain hardness is located. Another locus of qTaHa-5DL also showed a significant impact on grain hardness index (HI) with HI increasing from ~ 20 to ~ 45 and hardness type changing from soft to mixed when Puroindolines are wild type. A kompetitive allele-specific PCR (KASP) marker for qTaHa-5DL was developed and the effectiveness of the QTL was confirmed in 184 breeding lines with the marker K-Ha5DL dividing wheat into two distinct categories. This new QTL can be effectively used to select soft or medium hard wheat.
Abstract Background and Objective There is still a lack of information about detailed dynamic changes in starch properties during malting among multiple barley varieties and correlations of starch properties with malting qualities. In this work, compositional, physicochemical, morphological, and structural properties of starches from four barley varieties at six time points across the malting process were first investigated to better understand the starch modification of barley malting. Furthermore, a total of 30 barley varieties were used to investigate the relationship between malting qualities and starch properties. The results provide a reference for breeding high‐malting quality barley based on starch properties. Findings Significant decreases in starch contents, paste viscosities, relative crystallinity, as well as the ratio of 1045/1022 cm −1 of starch, were exhibited, while comparatively small changes were found in the thermal parameters during malting. Amylose and amylopectin polymers were both hydrolyzed in malting. After malting, pits and holes were discovered on the surface of some starch granules. Four parameters of peak viscosity (PV), breakdown, peak time (PeT), and pasting temperature (PT) had significant correlations with diastatic power (DP), while the above four indicators together with amylose content, total starch content, onset temperature, peak temperature, and swelling power had significant correlations with malt extract (ME). Conclusions The trend of changes in starch properties among all four genotypes was similar. However, the variety with better malting quality showed a greater degree of measurements in some starch characters. Starch properties are mainly related to the two malting quality indicators of DP and ME. Significance and Novelty PV, breakdown, PeT, and PT had significant correlations with malting qualities.
Additional file 1: Table S1. Genotyping of the diagnostic markers and dKASP markers for plant height, grain hardness, and high-molecular-weight glutenin in 22 wheat varieties and germplasm resources. A, B, C, and D correspond to the genotypes in Table 1.
Additional file 2: Table S2. Genotyping of the dKASP markers for plant height, grain hardness, and high-molecular-weight glutenin in 212 wheat varieties approved from 1966 to 2021 growing in the middle and lower reaches of the Yangtze River. A, B, C, and D correspond to the genotypes in Table 1.
Owing to successful cloning of wheat functional genes in recent years, more traits can be selected by diagnostic markers, and consequently, effective molecular markers will be powerful tools in wheat breeding programs.The present study proposed a cost-effective duplex Kompetitive Allele Specific PCR (dKASP) marker system that combined multiplex PCR and KASP™ technology to yield twice the efficiency at half the cost compared with the common KASP™ markers and provide great assistance in breeding selection. Three dKASP markers for the major genes controlling plant height (Rht-B1/Rht-D1), grain hardness (Pina-D1/Pinb-D1), and high-molecular-weight glutenin subunits (Glu-A1/Glu-D1) were successfully developed and applied in approved wheat varieties growing in the middle and lower reaches of the Yangtze River and advanced lines from our breeding program. Three markers were used to test six loci with high efficiency. In the approved wheat varieties, Rht-B1b was the most important dwarfing allele, and the number of accessions carrying Pinb-D1b was much greater than that of the accessions carrying Pina-D1b. Moreover, the number of accessions carrying favorable alleles for weak-gluten wheat (Null/Dx2) was much greater than that of the accessions carrying favorable alleles for strong-gluten wheat (Ax1 or Ax2*/Dx5). In the advanced lines, Rht-B1b and Pinb-D1b showed a significant increase compared with the approved varieties, and the strong-gluten (Ax1 or Ax2*/Dx5) and weak-gluten (Null/Dx2) types also increased.A cost-effective dKASP marker system that combined multiplex PCR and KASP™ technology was proposed to achieve double the efficiency at half the cost compared with the common KASP™ markers. Three dKASP markers for the major genes controlling PH (Rht-B1/Rht-D1), GH (Pina-D1/Pinb-D1), and HMW-GS (Glu-A1/Glu-D1) were successfully developed, which would greatly improve the efficiency of marker-assisted selection of wheat.