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Key message The vacuolar processing enzyme gene TaVPE3cB is identified as a candidate gene for a QTL of wheat pith-thickness on chromosome 3B by BSR-seq and differential expression analyses. Abstract The high pith-thickness (PT) of the wheat stem could greatly enhance stem mechanical strength, especially the basal internodes which support the heavier upper part, such as upper stems, leaves and spikes. A QTL for PT in wheat was previously discovered on 3BL in a double haploid population of ‘Westonia’ × ‘Kauz’. Here, a bulked segregant RNA-seq analysis was applied to identify candidate genes and develop associated SNP markers for PT. In this study, we aimed at screening differentially expressed genes (DEGs) and SNPs in the 3BL QTL interval. Sixteen DEGs were obtained based on BSR-seq and differential expression analyses. Twenty-four high-probability SNPs in eight genes were identified by comparing the allelic polymorphism in mRNA sequences between the high PT and low PT samples. Among them, six genes were confirmed to be associated with PT by qRT-PCR and sequencing. A putative vacuolar processing enzyme gene TaVPE3cB was screened out as a potential PT candidate gene in Australian wheat ‘Westonia’. A robust SNP marker associated with TaVPE3cB was developed, which can assist in the introgression of TaVPE3cB.b in wheat breeding programs. In addition, we also discussed the function of other DEGs which may be related to pith development and programmed cell death (PCD). A five-level hierarchical regulation mechanism of stem pith PCD in wheat was proposed.

Objective. To analyze the effect of hand intensive training on upper limb function of stroke patients with hemiplegia, Methods. 110 stroke patients were randomly divided into two groups: the reference group and the observation group. 55 patients in the reference group were treated with routine rehabilitation treatment, including routine joint activity training, bed training, exercise therapy, and ADL ability training; 55 cases in the observation group received intensive hand training on the basis of routine rehabilitation treatment, including inducing the patient’s five finger extension, forcibly pulling the fingers and wrist joints, and suddenly opening his fist after clenching his fist. Results. The treatment period of the two groups was 5 weeks. In the comparison results of Fugl-Meyer (FMA), the exercise effect of the observation group with increased hand intensive training was significantly better than that of the control group with stroke hemiplegia treated with conventional methods. The difference was statistically significant, t < 10.000 , P < 0.05 ; In the comparative analysis of upper limb function test (UEFT), the effect of the observation group was significantly higher than that of the reference group treated with routine rehabilitation nursing (all P < 0.05 ); In the comprehensive comparison of exercise ability results, the observation group was higher than the reference group in the flexibility, fineness, and fineness of activity behavior after treatment. Conclusion. Strengthening hand intensive training can further improve the upper limb motor function of stroke patients with hemiplegia, reduce the severity of hemiplegia, and improve the recovery effect of stroke patients. It is worthy of clinical promotion and application.

The middle to lower reaches of the Yangtze River are China’s second largest area for wheat production; wheat disease is more serious there than in other areas because of the high humidity and warm weather. However, most cultivated varieties are susceptible to Fusarium head blight (FHB), powdery mildew, and stripe rust, and the lack of disease-resistant germplasm is an obstacle in wheat breeding. Rye and Thinopyrum elongatum, related species of wheat, carry many genes involved in disease resistance. In this study, a trigeneric hybrid, YZU21, with resistance to FHB, powdery mildew, and stripe rust was used to improve two major wheat cultivars, Ningmai 13 (NM13) and Yangmai 23 (YM23). Specific molecular markers and GISH were used to identify hybrid progenies. Five addition or substitution lines and one translocation line of the Triticum-Secale-Thinopyrum trigeneric hybrid were obtained and evaluated for agronomic traits and the resistance to multiple diseases. The results showed that the six trigeneric hybrid lines had desirable agronomic traits and improved resistance to FHB, powdery mildew, and stripe rust; they might be used as parents in wheat breeding for the resistance to multiple disease.

Fusarium head blight (FHB) is one of the prevalent fungal diseases of wheat worldwide. Exploring new FHB resistance quantitative trait loci (QTL) in adapted wheat cultivars is a critical step for breeding new FHB-resistant cultivars. In this study, we developed a population of 236 F5:7 recombinant inbred lines (RILs) using two popular Chinese wheat cultivars, Yangmai 158 and Zhengmai 9023, with moderate FHB resistance to identify the QTL for FHB type II resistance. This population was evaluated for percentage of symptomatic spikelets per spike (PSS) using single floret injection in repeated greenhouse experiments. Mean PSSs were 33.2% for Yangmai 158 and 30.3% for Zhengmai 9023. A genetic linkage map of 1002 single nucleotide polymorphisms (SNPs) generated by genotyping-by-sequencing (GBS) was constructed for the RIL population. Six QTL were identified for FHB resistance, and three of them were repeatable in the both experiments. Zhengmai 9023 contributed the resistance allele at one repeatable QTL, designated as Qfhb.7D, whereas Yangmai 158 contributed the resistance alleles at the other two repeatable QTL, Qfhb.3AL and Qfhb.2DS. The additional QTL, Qfhb.4AS was significant in the mean PSS, and Qfhb.2DL and Qfhb.7AS were significant in only one experiment. Replacement of each allele individually at the three repeatable QTL significantly changed PSSs. Qfhb.3AL, Qfhb.2DS, and Qfhb.7D explained 8.35% to 9.89%, 5.13% to 7.43%, and 6.15% to 9.32% of the phenotypic variations, respectively. The three repeatable QTL contributed by the two parents were additive and stacking the resistance alleles from all the three repeatable QTL showed the highest level of resistance in the current RIL population. Ten SNPs in the QTL regions of Qfhb.3AL, Qfhb.2DS, and Qfhb.7D were converted into KBioscience competitive allele-specific PCR (KASP) assays. One KASP marker for Qfhb.3AL was validated in a panel of wheat cultivars from China. Some of these KASP markers could be useful for marker-assisted selection to stack these QTL.

The lack of remote sensing images and poor quality limit the performance improvement of follow-up research such as remote sensing interpretation. In this article, a generative adversarial network (GAN) is proposed for data augmentation of remote sensing images abstracted from Jiangxi and Anhui Provinces in China, i.e., deeply supervised GAN (D-sGAN). D-sGAN can generate high-quality images that are rich in changes, greatly shorten the generation time, and provide data support for applications such as semantic interpretation of remote sensing images. First, to modulate the layer activations, a downsampling scheme is designed based on the segmentation map. Then, the architecture of the generator is Unet++ with the proposed downsampling module. Next, the generator of this net is deeply supervised by the discriminator using deep convolutional neural network. This article further proved that the proposed downsampling module and the dense connection characteristics of UNet++ are significantly beneficial to the retention of semantic information of remote sensing images. Numerical results demonstrated that the images generated by D-sGAN could be used to improve accuracy of the segmentation network, with the faster generation speed compared to the CoGAN, SimGAN, and CycleGAN models. Furthermore, the remote sensing data generated by the model helped the interpretation network to increase the accuracy by 9%, meeting actual generation requirements.

In recent years, the annual demand for soft wheat in China has exceeded six million metric tons. The development of soft wheat is an important objective in the Yangtze River Basin winter wheat region in China. Ningmai 9 is a soft wheat cultivar widely used as a parent in the soft red winter wheat breeding program. However, the physicochemical and rheological properties of Ningmai 9 and its derivatives remain unknown. In this study, Ningmai 9 and its thirty-one derivatives were grown in Nanjing in Jiangsu Province in two successive cropping seasons from 2015 to 2017. The kernel samples were analyzed for milling quality, solvent retention capacity (SRC), alveograph parameters, and sugar-snap cookie diameter. The flour protein content was not significantly associated with any other quality trait. P, L, P/L (the ratio of tenacity to extensibility), alveograph deformation work (W), and four types of SRC were significantly correlated with sugar-snap cookie diameter. Compared to Ningmai 9, seven wheat genotypes had relatively better cookie quality and lower SRC and P values. A multiple regression model with water SRC (WSRC) as a variable explained 72.5% of the total variation in cookie diameter. These results suggest that decreasing SRC and gluten strength is the key to improving soft wheat breeding programs.

Mitogen-activated protein kinase (MAPK) cascades play crucial roles in almost all biological processes in plants. They transduce extracellular cues into cells, typically through linear and sequential phosphorylation and activation of members of the signaling cascades. However, accumulating data suggest various regulatory mechanisms of plant MAPK cascades in addition to the traditional phosphorylation pathway, in concert with their large numbers and coordinated roles in plant responses to complex ectocytic signals. Here, we highlight recent studies that describe the uncanonical mechanism of regulation of MAPK cascades, regarding the activation of each tier of the signaling cascades. More particularly, we discuss the unusual role for MAPK kinase kinases (MAPKKKs) in the regulation of MAPK cascades, as accumulating data suggest the non-MAPKKK function of many MAPKKKs. In addition, future work on the biochemical activation of MAPK members that needs attention will be discussed.

The area between middle and lower reaches of the Yangtze River is the largest region for soft wheat production in China. In soft wheat breeding, the lack of germplasm with desirable quality for end-use products is a barrier. Ningmai9 is the main variety of soft wheat planted in this area. To create germplasm with better quality and yield potential than Ningmai9, mutants of HMW-GSs in Ningmai9 induced by ethylmethanesulfonate (EMS) were obtained. SDS-PAGE showed that two mutants, md10 and md11, were HMW-GS 1Dy deletions. DNA sequencing confirmed that one mutation was caused by a C/T substitution, resulting in the change of CAA encoding glutamine into the termination codon TAA, and another mutation was due to a G/A substitution in the central repetitive domain of the coding region, causing TGG encoding tryptophan to become the termination codon TGA. The premature termination codon of the

Fusarium head blight (FHB) of wheat is a destructive fungal disease worldwide and has become more severe over the last two decades. Development of FHB resistant wheat varieties is the most effective way to manage FHB. The middle and lower reaches of the Yangtze River are the traditional FHB epidemic areas in China. The landraces and germplasms with resistance to FHB originating from this region were used to identity FHB resistance quantitative trait loci (QTLs). Yangmai 158 and Ningmai 9 are the most popular varieties for commercial wheat production in this region and both have moderate FHB resistance. A high‐density genetic map was constructed using 282 recombinant inbred lines (RILs) from a cross between Ningmai 9 and Yangmai 158. Ten QTLs related to Type II FHB resistance were identified, and QFhb‐3B.1 and QFhb‐5A were stably detected across all environments. Based on position alignment, QFhb‐3B.1 from Ningmai 9 is likely to be Fhb1 and QFhb‐5A from Yangmai 158 is a novel QTL not previously described. A competitive allele‐specific PCR (KASP) marker closely linked to QFhb‐5A was developed and could be used for marker‐assisted selection. Distribution of QFhb‐5A was tested with numerous accessions from a widespread core collection. The results suggest that QFhb‐5A has undergone both natural and artificial selection. Some RILs with both Fhb1 and QFhb‐5A presented better FHB resistance than the parents and could be used in FHB resistance breeding.

High molecular weight glutenin subunits (HMW-GSs) are important components of wheat (Triticum aestivum L.) gluten proteins that affect the processing quality of wheat dough. However, the contributions of individual HMW-GS to sponge cake quality still remain unclear. To investigate the effects of 1Bx7 and 1By9 at Glu-B1 on wheat gluten properties and sponge cake quality, we screened an ethylmethanesulfonate (EMS)-mutagenized wheat population and obtained two independent mutants that lack 1Bx7 and another two mutants that lack 1By9. The absence of 1Bx7 or 1By9 significantly affects the accumulation levels of gluten proteins and the formation of a gluten network. Quality testing indicated that the lack of 1Bx7 or 1By9 leads to weaker dough strength and inferior sponge cake performance. These results demonstrate that 1Bx7 and 1By9 make important contributions to gluten functionality and sponge cake quality.

Fusarium head blight (FHB) is a devastating disease of wheat worldwide. Fhb1 is the most consistently reported quantitative trait locus (QTL) for FHB resistance breeding. A pore-forming toxin-like (PFT) gene at Fhb1 was first cloned by map-based cloning and found to confer FHB resistance in wheat. Proteins often interact with each other to execute their functions. Characterization of the proteins interacting with PFT might therefore provide information on the molecular mechanisms of PFT functions. In this study, a high-quality yeast two-hybrid (Y2H) library using RNA extracted from Fusarium graminearum (Fg)-infected wheat spikes of Sumai 3 was constructed. The agglutinin domains of PFT exhibited no self-activation and toxicity to yeast cells and were used as bait to screen the Y2H library. Twenty-three proteins that interact with PFT were obtained, which were mainly involved in the ubiquitination process, clathrin coat assembly, the oxidation-reduction process, and protein phosphorylation. The expression pattern of these interacting genes was analyzed by quantitative real-time PCR. This study clarifies the protein interactions of PFT and raises a regulatory network for PFT regarding FHB resistance in wheat.

Wheat grain protein content (GPC) is an important quality indicator. The GPC of wheat grown in the middle and lower reaches of the Yangtze River is often low. Marker-assisted selection (MAS) is an effective tool for improving quantitative traits; however, except Gpc-B1, most markers have not been effectively applied in GPC improvement, although many related loci have been identified. Linkage analysis using a recombinant inbred line population from the cross of core parents of Ningmai 9 and Yangmai 158 and association mapping using the local cultivated varieties were performed and nine candidate intervals were identified. The appropriate kompetitive allele specific PCR (KASP) markers associated with GPC were successfully developed and applied in 1163 F4 breeding lines. Three markers, Kgpc-2B, Kgpc-2D, and Kgpc-4A, were validated to be significantly related to GPC by large-scale association mapping, and they were combined to achieve the highest efficiency to enhance GPC. We applied these markers in 164 F6 breeding lines and obtained 15 lines with high GPC, indicating their high selective efficiency. Further, strategies for gene exploration in the three significant intervals were proposed. These results were expected to provide a novel route for improving GPC in wheat quality breeding.

Linkage and association mapping identified nine candidate intervals for wheat GPC, and large-scale association mapping based on 9 corresponding KASP markers and 1163 F4 breeding lines revealed 3 significant markers. Wheat grain protein content (GPC) is an important quality indicator. The GPC of wheat grown in the middle and lower reaches of the Yangtze River is often low. Marker-assisted selection (MAS) is an effective tool for improving quantitative traits; however, most markers have not been effectively applied in GPC improvement except Gpc-B1, although many loci associated with GPC were identified. In this study, linkage analysis using a recombinant inbred line population from the cross of core parents of Ningmai 9 and Yangmai 158 and association mapping using the local cultivated varieties were performed and nine candidate intervals were identified. The appropriate kompetitive allele-specific PCR (KASP) markers associated with GPC were successfully developed and screened in 1163 F4 breeding lines. Three markers, Kgpc-2B, Kgpc-2D, and Kgpc-4A, were validated to be significantly related to GPC by large-scale association mapping, and they were combined to achieve the highest efficiency to enhance GPC. We applied these markers in 164 F6 breeding lines and obtained 15 lines with high GPC, indicating their high selective efficiency. Further, strategies for gene exploration in the three significant intervals were proposed. These results were expected to provide a novel route for improving GPC in wheat quality breeding.

Across domains of biological research using genome sequence data, high-quality reference genome sequences are essential for characterizing genetic variation and understanding the genetic basis of phenotypes. However, the construction of genome assemblies for various species is often hampered by complexities of genome organization, especially repetitive and complex sequences, leading to mis-assembly and missing regions. Here, we describe a high-throughput gold standard genome assembly workflow using a large-scale bacterial artificial chromosome (BAC) library with a refined two-step pooling strategy and the Lamp assembler algorithm. This strategy minimizes the laborious processes of physical map construction and clone-by-clone sequencing, enabling inexpensive sequencing of several thousand BAC clones. By applying this strategy with a minimum tiling path BAC clone library for the short arm of chromosome 2D (2DS) of bread wheat, 98% of BAC sequences, covering 92.7% of the 2DS chromosome, were assembled correctly for this species with a highly complex and repetitive genome. We also identified 48 large mis-assemblies in the reference wheat genome assembly (IWGSC RefSeq v1.0) and corrected these large mis-assemblies in addition to filling 92.2% of the gaps in RefSeq v1.0. Our 2DS assembly represents a new benchmark for the assembly of complex genomes with both high accuracy and efficiency.

This study aims to understand the starch molecular structural changes from baking sugar-snap cookies. Changes in the whole-molecule size distribution and chain-length distribution of the parent wheat flour and from final cookie products were measured by size-exclusion chromatography with and without enzymatic debranching, and the results fitted by two biosynthesis-based models. Fraction crystallinity was also analyzed. After cooking, there was a significant decrease in average molecular sizes of amylopectin and in the average lengths of amylose chains, and some starch granules lost birefringence. However, the chain-length distributions of amylopectin showed no noticeable difference, resulting in little change in relative crystallinity and gelatinization temperatures. Both the short-range ordered structure and the periodic lamellar structure were disrupted. This study provides new insight into starch structural changes in sugar-snap cookies after baking, which play an important role in determining final cookie quality. For example, a decrease in size of amylose chains influences cookie sensory properties, and thus can be used as an additional tool for choice of grains.

Fusarium head blight (FHB) is a destructive fungal disease in wheat worldwide. Efforts have been carried out to combat this disease, and the pore-forming toxin-like (PFT) gene at the quantitative trait locus (QTL) Fhb1 was isolated and found to confer resistance to FHB in Sumai 3. In this study, we characterized PFT in 348 wheat accessions. Four haplotypes of PFT were identified. The wild haplotype of PFT had higher resistance than other haplotypes and explained 13.8% of phenotypic variation in FHB resistance by association analysis. PFT was highly expressed during early flowering and increased after Fusarium graminearum treatment in Sumai 3. Analysis of the 5′ flanking sequence of PFT predicted that the cis elements of the PFT promoter were related to hormones and biological defense responses. However, PFT existed not only in the FHB-resistant accessions but also in some susceptible accessions. These results suggested that FHB resistance in a diverse range of wheat genotypes is partially conditioned by PFT. The profiling of FHB resistance and the PFT locus in this large collection of wheat germplasm may prove helpful for incorporating FHB resistance into wheat breeding programs, although more work is needed to reveal the exact role of the QTL Fhb1 in conferring resistance to fungal spread.

La3+ and Ce3+ have positive effects on plant growth and production. Although it is well known that rare earth elements promote cell growth, the biological effects of La3+ and Ce3+ on callus, shoot and root induction in tobacco are still unclear. The relationships among callus induction, rooting, enzyme activities and stomatal characteristics in tobacco are unknown. The objectives of this study were to identify the relationships between the induction of calluses, shoots, roots, stomata and enzyme activities. The induction percentages of calluses, buds, roots were recorded at 5, 10, 15, 20 and 25 days after La3+ and Ce3+ treatments. Peroxidase isoenzyme activity was determined by electrophoresis. The characteristics of the stomata were observed under an optical microscope. Our results show that low concentrations of Ce3+ ( 5 mg/L) inhibits the induction of calluses, buds and roots. There are more peroxidase isoenzyme bands in Ce3+ treatments than in La3+ treatments. This is consistent with the induction percentages of calluses, buds and roots in Ce3+ and La3+ treatments. High enzyme activities may promote the induction of calluses, buds and roots. The stomata area and stomata number of leaves are significantly different between La3+ treatments and Ce3+ treatments. La3+ improves the stomata area and number. Based on these results, we speculate that La3+ may promote the development of the photosynthetic system. Ce3+ may promote tobacco growth and rooting by improving enzyme activities.

Fusarium head blight (FHB) is a severe global wheat disease that may cause severe yield losses, especially during epidemic years. Transforming the regulatory genes in the metabolic pathways of disease resistance into wheat via transgenic methods is one way to improve resistance to FHB. ScNPR1 (Secale cereale-NPR1), a regulatory gene for systemic acquired resistance (SAR), was isolated from S. cereale cv Jingzhouheimai and transformed into the moderately FHB-susceptible wheat variety Ningmai 13. RT-PCR analysis indicated that the ScNPR1 gene was stably expressed in transgenic plants. An evaluation of the resistance to FHB revealed that six ScNPR1 transgenic lines (NP1, NP2, NP3, NP4, NP5 and NP6) exhibited significantly higher FHB resistance than the wild-type wheat Ningmai 13 and the null-segregated plants. The expression of pathogenesis-related (PR) genes after Fusarium graminearum inoculation was earlier or higher than those in the wild-type variety Ningmai 13. The high expression in the early stages of PR genes should account for the enhanced FHB resistance in the transgenic lines. Our results suggest that overexpression of ScNPR1 could be used to improve FHB resistance in wheat.

Arsenic (As) and cadmium (Cd) typically exhibit divergent fates in soil, which complicates efforts to decrease As and Cd accumulation in the edible parts of crops. Here, we performed pot experiments to examine the effect of sulfate application on As and Cd accumulation in the grain of wheat grown in contaminated soil. Compared to the control (no sodium sulfate addition), application of 120 mg kg−1 sodium sulfate decreased the rhizosphere soil pH from 7.27 to 7.10 and increased the soil extractable Cd concentration; however, it did not significantly influence the soil extractable As concentration. However, sodium sulfate addition decreased As and Cd concentrations in wheat grain, in association with decreased As and Cd translocation from root and straw to grain, rather than from soil to root. Furthermore, sodium sulfate addition significantly decreased membrane lipid peroxidation and enhanced photosynthesis, while increasing the uptake of nitrogen, phosphorus, and sulfur. These effects increased the growth and grain weight of plants grown in As and Cd co-contaminated soil. Our findings provide insight into the mechanisms by which sulfate modulates As and Cd uptake and translocation in wheat; moreover, our findings will enable formulation of strategies to decrease As and Cd concentrations in the grain of wheat grown in As and Cd co-contaminated soil.

This first systematic characterization of the whole wheat NPF gene family contributes to a better understanding of this large gene family in wheat and lays the foundation for further functional analysis., NPF genes encode membrane transporters involved in the transport of a large variety of substrates including nitrate and peptides. The NPF gene family has been described for many plants, but the whole NPF gene family for wheat has not been completely identified. The release of the wheat reference genome has enabled the identification of the entire wheat NPF gene family. A systematic analysis of the whole wheat NPF gene family was performed, including responses of specific gene expression to development and nitrogen supply. A total of 331 NPF genes (113 homoeologous groups) have been identified in wheat. The chromosomal location of the NPF genes is unevenly distributed, with predominant occurrence in the long arms of the chromosomes. The phylogenetic analysis indicated that wheat NPF genes are closely clustered with Arabidopsis, Brachypodium, and rice orthologues, and subdivided into eight subfamilies. The expression profiles of wheat NPF genes were examined using RNA-seq data, and a subset of 44 NPF genes (homoeologous groups) with contrasting expression responses to nitrogen and/or development in different tissues were identified. The systematic identification of gene composition, chromosomal locations, evolutionary relationships, and expression profiles contributes to a better understanding of the roles of the wheat NPF genes and lays the foundation for further functional analysis in wheat.

High molecular weight glutenin subunits (HMW-GSs) are important components of wheat (

Improving resistance to Fusarium head blight (FHB) in wheat is crucial in the integrated management of the disease and prevention of deoxynivalenol (DON) contamination in grains. To identify novel sources of resistance, a genome-wide association study (GWAS) was performed using a panel of 213 accessions of elite wheat germplasm of China. The panel was evaluated for FHB severity in four environments and DON content in grains in two environments. High correlations across environments and high heritability were observed for FHB severity and DON content in grains. The panel was also genotyped with the 90K Illumina iSelect single nucleotide polymorphism (SNP) array and 11,461 SNP markers were obtained. The GWAS revealed a total of six and three loci significantly associated with resistance to fungal spread and DON accumulation in at least two environments, respectively. QFHB-2BL.1 tagged by IWB52433 and QFHB-3A tagged by IWB50548 were responsible for resistance to both fungal spread and DON accumulation. In summary, this study provided an overview of FHB resistance resources in elite Chinese wheat germplasm and identified novel resistance loci that could be used for wheat improvement.

The rheological and thermal properties of wheat flour are important for eating and processing quality of flour-based foods. These properties are in part affected by the structure of the component starch, but the mechanisms underlying this are not well understood. In this study, the thermal and rheological properties of wheat-flour paste for 16 wheat varieties were measured and the results fitted with two standard models. Starch molecular structures were measured by fluorophore-assisted carbohydrate electrophoresis and size-exclusion chromatography. The resulting chain-length distributions of amylopectin and amylose were fitted using biosynthesis-based models, thereby representing the data in terms of biologically-meaningful parameters. Protein content was also measured. This gave quantitative relations between starch molecular fine structure and rheological and thermal properties of wheat flour paste. Long amylopectin chains were positively correlated with peak and conclusion temperatures, viscosity was positively, and elasticity negatively, correlated with the length of amylopectin short chains, while protein content showed no significant correlation with rheological and thermal properties. These results indicate that starch fine structure provides additional criteria for the selection of wheat varieties, complementary to the common use of protein composition and amylose content.

Two wheat (Triticum aestivum L.) cultivars differing in arsenic (As)-tolerance were used to investigate the effects of phosphorus (P) concentration and nutrient solution pH on As(V) toxicity and As(V) uptake kinetics, and to illustrate the mechanism of As(V) tolerance in wheat seedlings. Low pH and low phosphate concentration enhanced wheat uptake of As, resulting in high As toxicity. The As(V)-tolerant cultivar MM45 exhibited higher relative root elongation than non-tolerant cultivar HM29 in all treatments, except that no genotypic difference was recorded for the solution P at 100 μmol L−1 or greater. Wheat seedling As(V) tolerance was positively correlated with P concentration in roots and shoots. In short-term (30 min) As(V)-uptake kinetics experiments, the maximum influx rate (Vmax) of As(V) increased with decreasing solution pH (from 7.0 to 6.0). Compared with HM29, although MM45 had lower Vmax, its Michaelis–Menten constant (Km) did not exceed that of HM29 in all treatments. The Vmax values of both cultivars were not significantly affected by phosphate treatments, except for HM29 which had significantly higher Vmax value in the presence of phosphate at pH 7.0. The Km values of the two cultivars increased by 9- to 20-fold when phosphate was present as opposed to absent from the uptake solution. This study showed that the Vmax values are mainly increased by high pH and As(V) uptake Km is mainly increased by phosphate presence. Decreased As(V) influx rates during early stages and increased P concentration in plant tissues are associated with increased As tolerance in wheat seedlings.

Fusarium head blight (FHB), which is mainly caused by Fusarium graminearum, is a destructive wheat disease that threatens global wheat production. Fhb1, a quantitative trait locus discovered in Chinese germplasm, provides the most stable and the largest effect on FHB resistance in wheat. Here we show that TaHRC, a gene that encodes a putative histidine-rich calcium-binding protein, is the key determinant of Fhb1-mediated resistance to FHB. We demonstrate that TaHRC encodes a nuclear protein conferring FHB susceptibility and that a deletion spanning the start codon of this gene results in FHB resistance. Identical sequences of the TaHRC-R allele in diverse accessions indicate that Fhb1 had a single origin, and phylogenetic and haplotype analyses suggest that the TaHRC-R allele most likely originated from a line carrying the Dahongpao haplotype. This discovery opens a new avenue to improve FHB resistance in wheat, and possibly in other cereal crops, by manipulating TaHRC sequence through bioengineering approaches.

Fusarium head blight (FHB), also called scab, is a devastating and insidious disease of cereals including wheat (Triticum spp.) and barley (Hordeum vulgare L.) worldwide. Apart from direct yield losses, the most serious concern about FHB is the contamination of the crop with mycotoxins, which pose a health risk to human and livestock. Recent research reported that phylogenetic species F. asiaticum (Fa) and F. graminearum (Fg) were the major causal agents of FHB from infected wheat heads in China. To investigate the population structure of Fusarium species in China by species-specific as well as the chemotype-specific markers, sequence-related amplified polymorphism (SRAP) markers were screened on representative isolates of F. asiaticum-NIV, F. asiaticum- 3ADON and F. graminearum-15ADON to find amplification products characteristic of either species or chemotypes. Selected amplified fragments were cloned and sequenced so that sequence-characterized amplified region (SCAR) primer pairs could be developed which permit specific detection of Fusarium species using conventional PCR. Primer pairs SCAR-Fa1 and SCAR-Fg1 were confirmed to be able to amplify specific products only in F. asiaticum and F. graminearum isolates, respectively. These species-specific primers were applied to determine genetic division of F. asiaticum and F. graminearum isolates collected in Yangtze–Huaihe valley. The results indicated that F. asiaticum was the predominant species causing FHB in this wheat production area. It is the first report that SRAP markers were adapted for species characterization in Fusarium isolates.

Plant basic-leucine zipper (bZIP) transcription factors play important roles in many biological processes. In the present study, a bZIP gene, GmbZIP60 (Genebank Accession No: DQ787038), was cloned from soybean and has 86.5 % and 57.4 % similarity with GmbZIP59 and MtbZIP60 respectively. Among all of the organs analyzed, its expression was the highest in early and blooming leaves. Real-Time PCR showed the expression level of GmbZIP60 was induced by ABA and salt stresses. Promoter analysis indicated that the GmbZIP60 promoter has some cis-acting elements involved in defense and stress responsiveness. Arabidopsis thaliana plants heterologous expression GmbZIP60 promoter showed that the expression of GmbZIP60 participated in the entire development process of plant. All results showed that GmbZIP60 perhaps was a new member of bZIP family in G. max and involved in different stress signaling pathways, so it can either be used as a new resource in gene engineering on stress tolerance or be further studied to provide more information for the researches on the mechanism of stress tolerance in plant.

In this paper, we isolated and characterized a gene encoding the soybean MYB transcription factor, GmMYB39 (Accession No: XM_003538605). Analysis of the deduced amino acid sequence revealed that GmMYB39 contained N-terminal R2R3 repeats that corresponded to the DNA-binding domain of plant MYB-type proteins, which were highly conserved among the R2R3-MYB proteins. The detailed expression pattern of GmMYB39 in various tissues of soybean was investigated by quantitative RT-PCR. The transcript level was found to be higher in flowers than in other examined organs. In contrast, the GmMYB39 expression level was relatively weak in the pod. The GmMYB39–GFP fusion protein was found to localize in the nucleus of Arabidopsis mesophyll protoplasts. Over-expression of GmMYB39 in hairy roots resulted in a significant reduction of the transcript levels of PAL, C4H, CHS, 4CL, and CHR. Whereas, the IFS transcript level was slightly but not significantly increased, and no significant change in CHI expression was observed between over-expression and control roots. The repressing effect on expression of CHS was further supported by the results from co-transfection assays of CHS promoter (reporter) and GmMYB39 (effector) in soybean. Compared to the control (only with the reporter construct), a significant decrease in the GUS activity was observed in soybean hairy roots with both effector and reporter constructs. Furthermore, an ultimate decrease in isoflavonoids contents coincided with the decrease in the transcript levels of PAL, C4H, CHS, 4CL, and CHR. Overall, the results suggest that GmMYB39 plays an inhibiting role in regulating the isoflavonoid biosynthesis in soybean.