Low-molecular-weight glutenin subunits (LMW-GS) are of great importance in processing quality and participate in the formation of polymers in wheat. In this study, eight new LMW-GS alleles were ...isolated from Chinese wheat landraces (Triticum aestivum L.) and designated as Glu-A3-1a, Glu-A3-1b, Glu-B3-1a, Glu-B3-1b, Glu-B3-1c, Glu-D3-1a, Glu-D3-1b, and Glu-D3-1c, which were located at the Glu-A3, Glu-B3, and Glu-D3 loci, respectively. Based on the proteins encoded, the number of deduced amino acids of Glu-B3 alleles was approximately 50 more than those of Glu-A3 and Glu-D3 alleles. The first cysteine of Glu-A3 and Glu-D3 alleles was located at the N-terminal domain, while that of Glu-B3 alleles was found in the repetitive domain, which may lead to the different functioning in forming disulfide bonds. All the eight genes were LMW-m types and the new allele of Glu-B3-1a which had nine cysteine residues may be the desirable LMW-GS gene for improving bread-making quality.
Full text
Available for:
FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Wheat yellow rust (YR) caused by Puccinia striiformis is lethal for the leaf photosynthetic process, which substantially affects yield components and ultimately causes drastic yield reduction. The ...current study aimed to identify all-stage YR resistance linked QTLs in the best cross-combination. Experimental materials were phenotyped for disease severity in YR-hot spot area at Cereal Crops Research Institute, Pirsabak Pakistan in Khyber Pakhtunkhwa province in 2019 and 2020 and 2020 and 2021 Rabi seasons. The AN179 × KS17 was found to be the best cross combination, which showed high resistance to YR, whereas crosses AN179 × PK15 and PR129 × PK15 demonstrated susceptibility to YR with high disease severity. The recombinant inbred lines (RIL) F2 wheat population Annong-179/Khaista-17 demonstrated highly desirable YR resistance and yield component traits. Simple sequence repeat (SSR) markers were used to genotype the RIL population and their parents. Three novel QTLs linked to all-stage YR resistance were found on chromosomes 2BS, 3BS and 6BS, which explained 1.24, 0.54, and 0.75 phenotypic variance, respectively. Incorporation of the newly identified novel YR-resistance associated QTLs into hybridization wheat breeding program could be effective for marker-assisted selection of the improved and sustainable resistance.
Wheat is one of the most widely cultivated food crops worldwide, and the safe production of wheat is essential to ensure food security. Soil salinization and drought have severely affected the yield ...and quality of wheat. Valine-glutamine genes play important roles in abiotic stress response. This study assessed the effect of the gene
on drought and salt stresses resistance. Sequence analysis showed that TaVQ14 encoded a basic unstable hydrophobic protein with 262 amino acids. Subcellular localization showed that TaVQ14 was localized in the nucleus.
was upregulated in wheat seeds under drought and salt stress. Under NaCl and mannitol treatments, the percentage of seed germination was higher in Arabidopsis lines overexpressing
than in wild-type lines, whereas the germination rate was significantly lower in plants with a mutation in the
gene (a
homolog) than in WT controls, suggesting that
increases resistance to salt and drought stress in Arabidopsis seeds. Moreover, under salt and drought stress, Arabidopsis lines overexpressing
had higher catalase, superoxide dismutase, and proline levels and lower malondialdehyde concentrations than WT controls, suggesting that
improves salt and drought resistance in Arabidopsis by scavenging reactive oxygen species. Expression analysis showed that several genes responsive to salt and drought stress were upregulated in Arabidopsis plants overexpressing
. Particularly, salt treatment increased the expression of
in these plants. Moreover, salt treatment increased Ca
concentrations in plants overexpressing
, suggesting that
enhances salt resistance in Arabidopsis seeds through calcium signaling. In summary, this study demonstrated that the heterologous expression of
increases the resistance of Arabidopsis seeds to salt and drought stress.
Identification and accurate mapping of new resistance genes are essential for gene pyramiding in wheat breeding. The
gene is a dominant stripe-rust-resistance gene located at the distal end of ...chromosome 2AL, which was identified in a leading Chinese-wheat variety, Jimai 22, showing high resistance to CYR32, a prevalent race of
(
) in China. In the current study, 15 F
and 2273 F
plants derived from the cross of Jimai 22/Avocet S were used for the fine-mapping of
. The RNA-Seq of resistant and susceptible bulks of F
plants (designated BSR-Seq) identified 10 single-nucleotide polymorphisms (SNP) in a 12.09 Mb physical interval on chromosome 2AL. A total of 1022 EMS-induced M
lines of Jimai 22 were screened, to identify susceptible mutants for MutMap analysis. Four CAPS markers were developed from SNPs identified using BSR-Seq and MutMap. A linkage map for
was constructed with 11 CAPS/STS and three SSR markers.
was located at a 0.9 cM genetic interval flanked by markers H736 and H400, corresponding to a 340.46 kb physical region (768.7-769.0 Mb), including 13 high-confidence genes based on the Chinese Spring reference genome.
is a potential candidate-gene, according to linkage and quantitative real-time PCR (qPCR) analyses. The CAPS marker H732 designed from an SNP in
co-segregated with
These results provide a useful stripe-rust-resistance gene and molecular markers for marker-assisted selection in wheat breeding and for further cloning of the gene.
Pre-harvest sprouting (PHS) is one of the most important factors having adverse effects on yield and grain quality all over the world, particularly in wet harvest conditions. PHS is controlled by ...both genetic and environmental factors and the interaction of these factors. Breeding varieties with high PHS resistance have important implications for reducing yield loss and improving grain quality. The rapid advancements in the wheat genomic database along with transcriptomic and proteomic technologies have broadened our knowledge for understanding the regulatory mechanism of PHS resistance at transcriptomic and post-transcriptomic levels. In this review, we have described in detail the recent advancements on factors influencing PHS resistance, including grain color, seed dormancy, α-amylase activity, plant hormones (especially abscisic acid and gibberellin), and QTL/genes, which are useful for mining new PHS-resistant genes and developing new molecular markers for multi-gene pyramiding breeding of wheat PHS resistance, and understanding the complicated regulatory mechanism of PHS resistance.
Improvement of grain weight and size is an important objective for high-yield wheat breeding. In this study, 174 recombinant inbred lines (RILs) derived from the cross between Jing 411 and ...Hongmangchun 21 were used to construct a high-density genetic map by specific locus amplified fragment sequencing (SLAF-seq). Three mapping methods, including inclusive composite interval mapping (ICIM), genome-wide composite interval mapping (GCIM), and a mixed linear model performed with forward-backward stepwise (NWIM), were used to identify QTLs for thousand grain weight (TGW), grain width (GW), and grain length (GL). In total, we identified 30, 15, and 18 putative QTLs for TGW, GW, and GL that explain 1.1-33.9%, 3.1%-34.2%, and 1.7%-22.8% of the phenotypic variances, respectively. Among these, 19 (63.3%) QTLs for TGW, 10 (66.7%) for GW, and 7 (38.9%) for GL were consistent with those identified by genome-wide association analysis in 192 wheat varieties. Five new stable QTLs, including 3 for TGW (
,
, and
) and 2 for GL (
and
), were detected by the three aforementioned mapping methods across environments. Subsequently, five cleaved amplified polymorphic sequence (CAPS) markers corresponding to these QTLs were developed and validated in 180 Chinese mini-core wheat accessions. In addition, 19 potential candidate genes for
in a 0.31-Mb physical interval were further annotated, of which
and
encode a plasma membrane H
-ATPase and a serine/threonine-protein kinase, respectively. These new QTLs and CAPS markers will be useful for further marker-assisted selection and map-based cloning of target genes.
The diurnal and seasonal temperature rising patterns "asymmetric warming," plays an important role in crop distribution and productivity. Asymmetric warming during the early growth periods of winter ...wheat (
L.) profoundly affects vegetative growth and post-anthesis grain productivity, but the underlying physiological mechanism is still unclear. We conducted field experiments from 2012 to 2014 using two wheat cultivars, namely, Yangmai-13 (vernal type) and Yannong-19 (semi-winter type), to investigate the influences of night-warming during the winter (warming by 1.56-1.67°C from tillering to jointing) or during the spring (warming by 1.78-1.92°C from jointing to booting) on post-anthesis physiological activities and grain-filling processes. Both night-warming treatments enhanced the source activity by increasing flag leaf area, chlorophyll content, and photosynthetic capability in both cultivars compared with those of the control. The night-warming treatments caused an increase in the antioxidant activities of superoxide dismutase (SOD), peroxidase, and catalase (CAT) in the flag leaves of both cultivars, while ROS contents such as superoxide anion radical (Formula: see text) and hydrogen peroxide (H
O
) decreased. Moreover, the expression levels of Rubisco activase B (
), major chlorophyll a/b-binding protein (
), chloroplast Cu/Zn superoxide dismutase (
), mitochondrial manganese superoxide dismutase (
), and
genes were upregulated at anthesis and were associated with higher photosynthetic capacity and antioxidant activities. Furthermore, night-warming improved sink activities by increasing the concentrations of grain indole-3-acetic acid and cytokinins as well as the sucrose synthase activity for both cultivars. Winter night-warming showed greater potential for improving source strength and grain filling, with consistent performance in both cultivars compared with that of spring night-warming. We concluded form these results that night-warming can improve source and sink capacities in winter wheat, and winter night-warming has greater advantages in this respect than does spring warming.
High temperature stress during grain filling substantially decreases wheat productivity; thus, to ensure food security, heat tolerance in wheat must be developed. It remains unclear whether exogenous ...salicylic acid (SA) can induce tolerance to high temperatures in wheat at the grain-filling stage. In this study, a two-year pot culture experiment using the wheat cultivar ‘Yangmai 18’ was conducted from 2018 to 2020. The plants were pre-sprayed with SA from the heading stage (SAH), anthesis stage (SAA), 5 days after anthesis (DAA; SA5), and 10 DAA (SA10). After that, the wheat plants were subjected to high temperature stress (G) simulated using a passive warming method during the period between 15 and 19 DAA. The results showed that, compared with the normal temperature control group (NN), high temperature stress at the grain-filling stage significantly reduced the yield and photosynthetic capacity of wheat. The application of SA at different stages reduced the yield loss and the damage to the photosynthetic capacity caused by high temperature stress; the effectiveness of the treatments in descending order was SAAG > SA5G > SA10G > SAHG. Exogenous SA treatment increased the amount and proportion of dry matter distributed in the stem sheaths and leaves and grains, and decreased the amount and proportion of dry matter distributed in the rachises and glumes at the maturity stage, thereby reducing the yield loss under high temperature stress. The application of SA significantly increased the leaf area, stomatal density, chlorophyll content, soluble protein content, maximum photochemical efficiency (Fv/Fm), actual photochemical efficiency (ΦPSII), and activity of sucrose phosphate synthase (SPS) of the wheat flag leaves under high temperature stress at the grain-filling stage, thereby improving the photosynthetic performance of the flag leaves under stress. In summary, exogenous SA significantly restored the photosynthetic capacity of wheat flag leaves injured by post-anthesis high temperature stress, which effectively alleviated the inhibition of wheat growth caused by the stress and ultimately reduced the yield loss. Spraying SA at the anthesis stage had the greatest effect abating the loss of yield and reduced photosynthetic performance under high temperature stress.
Yellow rust (YR) epidemics have affected wheat productivity worldwide. YR resistance (Yr) is eminent in wheat; however, it is continuously invaded by evolving YR pathogen Puccinia striiformis (Pst.). ...Understanding the Yr genes’ diversity among the available germplasm is paramount to developing YR-resistant cultivars. In this study, 14 wheat genotypes were screened for their relative resistance index (RRI) and Yr genes/QTL via linked microsatellite markers. RRI screening categorized the studied genotypes into susceptible (<5; 4.44 ± 0.75), moderate (5–7; 6.11 ± 0.64), and resistant (>7; 8.45 ± 0.25) bulks (p < 0.001). Genetic analysis using 19 polymorphic microsatellite markers revealed 256 alleles, which were divergent among the three resistance bulks. Markers Xbarc7 and Xgwm429 showed the highest allelic diversity in comparison to Xbarc181, Xwmc419, SCAR1400, and Xgwm130. Resistant bulk showed associated alleles at Yr18 gene-linked markers Xgwm295, cssfr6, and csLV34. Other RRI-associated alleles at markers Xbarc7 and Xbarc101 showed weak and moderate linkages, respectively, with the Yr5 gene; whereas, a moderate association was noted for the Yr15 gene-linked marker Xgwm11. Marker Xwe173 linked with the Yr26 gene showed associated alleles among the susceptible bulk. Cross combinations of the parental lines forming recombinant inbred lines (RILs) demonstrated net higher RRI implying favorable allelic recombination. These results support reports and field observations on novel Pst. races that triggered Yr26, Yr5, and Yr15 busts in recent past. This study further implies that pyramiding all stage resistance genes (Yr5, Yr10, Yr15, and Yr26) with adult plant resistance genes (Yr18 and Yr62) should provide sustained YR resistance. The associated alleles at Yr genes-linked markers provide a basis for marker-assisted YR resistance breeding in wheat.
Yellow rust (YR) globally affects wheat crops. It may turn into an epidemic, resulting in significant yield losses if the environment is suited to YR spread. The provision of resistant wheat ...cultivars is a sustainable protection strategy against YR. The current study aimed to use a combination of classical analytical tools to identify potential wheat lines through screening under YR stress for utilization in YR-resistance breeding. A total of 14 parents, which included 9 lines and 5 testers, were formed into 45 cross combinations via line × tester mating format. The tested germplasm was grown in a triplicate randomized full-block design, under optimal and yellow rust (YR)-stress conditions. Data were recorded on different morphological, physiochemical, yield and component traits at appropriate crop stages. A pre-combining ability analysis revealed significant inter-genotype variations. A combining ability study identified non-additive gene action in the inheritance of most of the investigated traits. Four potential parents (PR128, AN179, KS17 and WD17) and two crosses (PR128 × WD17 and AN179 × KS17) retained higher combining ability values for yield traits under YR-stress. A cluster analysis based on the overall performance found divergent classes among the screened genotypes. The clustering of different genotypes was shifted under YR-stress, which suggests variable genotypic response. Through factor analysis, we assessed and confirmed genotypes performing consistently under YR-stress. The identified genotypes may be used for disease-resistance breeding in wheat. Based on their positive correlation with grain yield, we suggest the use of peduncle length and tillers per plant as phenotypic markers for wheat selection and breeding. The knowledge base generated through the current study will add to the ongoing research on sustainable wheat breeding program.
PDF
