ABSTRACT
Powdery mildew caused by Blumeria graminis f. sp. tritici (Bgt) seriously threatens wheat production worldwide. It is imperative to identify novel resistance genes from wheat and its wild relatives to control this disease by host resistance. Dasypyrum villosum (2n = 2x = 14, VV) is a relative of wheat and harbors novel genes for resistance against multi-fungal diseases. In the present study, we developed a complete set of new wheat-D. villosum disomic introgression lines through genomic in situ hybridization (GISH), fluorescence in situ hybridization (FISH) and molecular markers analysis, including four disomic substitution lines (2n=42) containing respectively chromosomes 1V#6, 2V#6, 3V#6, and 6V#6, and four disomic addition lines (2n=44) containing respectively chromosomes 4V#6, 5V#6, 6V#6 and 7V#6. These lines were subsequently evaluated for their responses to a mixture Bgt isolates at both seedling and adult-plant stages. Results showed that introgression lines containing chromosomes 3V#6, 5V#6, and 6V#6 exhibited resistance at both seedling and adult-plant stages, whereas the chromosome 4V#6 disomic addition line NAU4V#6-1 exhibited a high level of adult plant resistance to powdery mildew. Moreover, two translocation lines were further developed from the progenies of NAU4V#6-1 and the Ph1b mutation line NAU0686-ph1b. They were T4DL·4V#6S whole-arm translocation line NAU4V#6-2 and T7DL·7DS-4V#6L small-fragment translocation line NAU4V#6-3. Powdery mildew tests of the two lines confirmed the presence of an adult-plant powdery mildew resistance gene, Pm4VL, located on the terminal segment of chromosome arm 4V#6L (FL 0.6-1.00). In comparison with the recurrent parent NAU0686 plants, the T7DL·7DS-4V#6L translocation line NAU4V#6-3 showed no obvious negative effect on yield-related traits, providing a new germplasm in breeding for resistance.
ABSTRACT
Stripe rust (Puccinia striiformis West. f.sp. tritici, Pst) is a destructive disease that seriously threatens wheat production globally. Exploring novel resistance genes for use in wheat breeding is an urgent need, as continuous Pst evolution frequently leads to a breakdown of host resistance. Here, we identified a set of wheat-Dasypyrum villosum 01I139 (V#6) disomic introgression lines for the purpose of determining their responses to a mixture of Pst isolates CYR32, CYR33 and CYR34 at both seedling and adult-plant stages. The results showed that all introgression lines exhibited high susceptibility at the seedling stage, with infection-type (IT) scores in the range of 6-8, whereas, for chromosomes 5V#6 and 7V#6, disomic addition lines NAU5V#6-1 and NAU7V#6-1 displayed high resistance at the adult-plant stage, indicating that adult-plant resistance (APR) genes were located on them. Further, in order to transfer the stripe-rust resistance on chromosome 7V#6, four new wheat-D. villosum introgression lines were identified, by the use of molecular cytogenetic approaches, from the self-pollinated seeds of 7D and 7V#6, in double monosomic line NAU7V#6-2. Among them, NAU7V#6-3 and NAU7V#6-4 were t7V#6L and t7V#6S monosomic addition lines, and NAU7V#6-5 and NAU7V#6-6 were homozygous T7DS·7V#6L and T7DL·7V#6S whole-arm translocation lines. Stripe-rust tests and genetic analyses of chromosome 7V#6 introgression lines revealed a dominant APR gene designated as Yr7VS on the chromosome arm 7V#6S. Comparison with the homozygous T7DL·7V#6S translocation line and the recurrent parent NAU0686 showed no significant differences in yield-related traits. Thus, T7DL·7V#6S whole-arm translocation with the APR gene Yr7VS provided a valuable germplasm for breeding for resistance.
ABSTRACT
KEY MESSAGE: Phenotypical, physiological and genetic characterization was carried out on the hybrid necrosis gene from Haynaldia villosa, and the related gene Ne-V was mapped to chromosome arm 2VL. Introducing genetic variation from wild relatives into common wheat through wide crosses is a vital strategy for enriching genetic diversity and promoting wheat breeding. However, hybrid necrosis, a genetic autoimmunity syndrome, often occurs in the offspring of interspecific or intraspecific crosses, restricting both the selection of hybrid parents and the pyramiding of beneficial genes. To utilize the germplasms of Haynaldia villosa (2n = 2x = 14, VV), we conducted wide hybridization between durum wheat (2n = 4x = 28, AABB) and multiple H. villosa accessions to synthesize the amphiploids (2n = 6x = 42, AABBVV). This study revealed that 61.5% of amphiploids derived from the above crosses exhibited hybrid necrosis, with some amphiploids even dying before reaching maturity. However, the initiation time and severity of necrosis varied dramatically among the progenies, suggesting that there were multiple genetic loci or multiple alleles in the same genetic locus conferring to hybrid necrosis in H. villosa accessions. Genetic analysis was performed on the F2 and derived F2:3 populations, which were constructed between amphiploid STH59-1 with normal leaves and amphiploid STH59-2 with necrotic leaves. A semidominant hybrid necrosis-related gene, Ne-V, was mapped to an 11.8-cM genetic interval on the long arm of chromosome 2V, representing a novel genetic locus identified in Triticum-related species. In addition, the hybrid necrosis was correlated with enhanced H2O2 accumulation and cell death, and it was influenced by the temperature and light. Our findings provide a foundation for cloning the Ne-V gene and exploring its molecular mechanism.
Subject(s)
Chromosome Mapping , Phenotype , Triticum , Triticum/genetics , Triticum/growth & development , Hybridization, Genetic , Poaceae/genetics , Chromosomes, Plant/genetics , Genes, Plant , Plant Breeding , Plant Diseases/genetics , Plant Diseases/microbiology , Crosses, Genetic , NecrosisABSTRACT
Powdery mildew, caused by Blumeria graminis f. sp. tritici (Bgt), is a serious disease that threatens wheat production globally. It is imperative to explore novel resistance genes to control this disease by developing and planting resistant varieties. Here, we identified a wheat-Dasypyrum villosum 3V (3D) disomic substitution line, NAU3815 (2n = 42), with a high level of powdery mildew resistance at both the seedling and adult-plant stages. Subsequently, NAU3815 was used to generate recombination between chromosomes 3V and 3D. Through genomic in situ hybridization (GISH), fluorescence in situ hybridization (FISH), and 3VS- and 3VL-specific markers analysis, four introgression lines were developed from the selfing progenies of 3V and 3D double monosomic line NAU3816, which was derived from the F1 hybrids of NAU3815/NAU0686. There were t3VS (3D) ditelosomic substitution line NAU3817, t3VL (3D) ditelosomic substitution line NAU3818, homozygous T3DL·3VS translocation line NAU3819, and homozygous T3DS·3VL translocation line NAU3820. Powdery mildew tests of these lines confirmed the presence of an all-stage and broad-spectrum powdery mildew resistance gene, Pm3VS, located on chromosome arm 3VS. When compared with the recurrent parent NAU0686 plants, the T3DL·3VS translocation line NAU3819 showed no obvious negative effect on yield-related traits. However, the introduction of the T3DL·3VS translocated chromosome had a strong effect on reducing the flag-leaf length. Consequently, the T3DL·3VS translocation line NAU3819 provides a new germplasm in breeding for both resistance and plant architecture.
Subject(s)
Ascomycota , Chromosomes, Plant , Disease Resistance , Plant Diseases , Triticum , Triticum/genetics , Triticum/microbiology , Plant Diseases/microbiology , Plant Diseases/genetics , Plant Diseases/immunology , Disease Resistance/genetics , Ascomycota/physiology , Ascomycota/genetics , Chromosomes, Plant/genetics , Poaceae/genetics , Poaceae/microbiology , Genes, Plant/genetics , Genetic Introgression/geneticsABSTRACT
The spikes of gramineous plants are composed of specialized units called spikelets. Two bracts at the spikelet bases are known as glumes. The spikelet glumes in barley are degenerated into threadlike structures. Here, we report a long glume mutant, lgm1, similar in appearance to a lemma with a long awn at the apex. Map-based cloning showed that the mutant lgm1 allele has an approximate 1.27 Mb deletion of in chromosome 2H. The deleted segment contains five putative high-confidence genes, among which HORVU.MOREX.r3.2HG0170820 encodes a C2H2 zinc finger protein, an ortholog of rice NSG1/LRG1 and an important candidate for the Lgm1 allele. Line GA01 with a long glume and short awn was obtained in progenies of crosses involving the lgm1 mutant. Interestingly, lsg1, a mutant with long glumes on lateral spikelets, was obtained in the progenies of the lgm1 mutant. The long glume variant increased the weight of kernels in the lateral spikelets and increased kernel uniformity across the entire spike, greatly improving the potential of six-rowed barley for malting. Supplementary Information: The online version contains supplementary material available at 10.1007/s11032-024-01448-x.
ABSTRACT
Powdery mildew poses a significant threat to wheat crops worldwide, emphasizing the need for durable disease control strategies. The wheat-Dasypyrum villosum T5AL·5 V#4 S and T5DL·5 V#4 S translocation lines carrying powdery mildew resistant gene Pm55 shows developmental-stage and tissue-specific resistance, whereas T5DL·5 V#5 S line carrying Pm5V confers resistance at all stages. Here, we clone Pm55 and Pm5V, and reveal that they are allelic and renamed as Pm55a and Pm55b, respectively. The two Pm55 alleles encode coiled-coil, nucleotide-binding site-leucine-rich repeat (CNL) proteins, conferring broad-spectrum resistance to powdery mildew. However, they interact differently with a linked inhibitor gene, SuPm55 to cause different resistance to wheat powdery mildew. Notably, Pm55 and SuPm55 encode unrelated CNL proteins, and the inactivation of SuPm55 significantly reduces plant fitness. Combining SuPm55/Pm55a and Pm55b in wheat does not result in allele suppression or yield penalty. Our results provide not only insights into the suppression of resistance in wheat, but also a strategy for breeding durable resistance.
Subject(s)
Ascomycota , Triticum , Triticum/genetics , Alleles , Ascomycota/genetics , Plant Breeding , Poaceae/genetics , Disease Resistance/genetics , Plant Diseases/geneticsABSTRACT
Electrochemical activation of persulfate (EA-PS) is gradually attracting attention as an emerging method for wastewater treatment. In this study, a novelty flow-through EA-PS system was first attempted for pollutants degradation using boron and cobalt co-doping carbon felt (B, Co-CF) as the cathode. SEM images, XPS and XRD spectra of B, Co-CF were investigated. The optimal doping ration between B and Co was 1:2. Increasing current density, PS concentration and flow rate, decreasing initial pH accelerated the removal of AO7. The mechanism involved in EA-PS were the comprehensive effect of DET, â¢OH and SO4â¢-. B, Co-CF cathode for flow-through system was stable with five cycles efficient AO7 decay performance. EA-PS in flow-through system was an efficient method with low cost and efficient pollutants degradation. This work provides a feasible strategy for synergistically enhancing PS activation and promoting the degradation of organic pollutants.
Subject(s)
Environmental Pollutants , Water Pollutants, Chemical , Carbon , Carbon Fiber , Oxidation-Reduction , Water Pollutants, Chemical/analysisABSTRACT
Wall-associated kinases (WAKs), a group of receptor-like kinases (RLKs), have been found to play important roles in defending against pathogens and in various developmental processes. However, the importance of this family in wheat remains largely unknown. Wheat powdery mildew is caused by Blumeria graminis f. sp. tritici (Bgt) which initiates infection on the cell surface and forms haustoria inside the cell, therefore, the defense to Bgt involves extracellular and subsequently intracellular signals. In this study, WAKs were identified genome-wide and phylogenetically analyzed, then a transmembrane WAK gene putatively participated in pathogen-associated molecular patterns (PAMPs)-triggered immunity (PTI) and effector-triggered immunity (ETI) to Bgt was functionally and evolutionarily investigated. In total, 1,193 WAKs were identified from wheat and its Gramineae relatives. Phylogenetic analysis indicated that WAKs expanded through tandem duplication or segment duplication. TaWAK7, from chromosome 2A, was identified as a Bgt-inducible gene both in susceptible and resistant materials but showed distinct responsive patterns. Functional analysis showed that TaWAK7 was involved in both the basal and resistance (R)-gene mediated resistances. The specific gene structures and protein characteristics of TaWAK7 together with its orthologs were characterized both in subgenomes of Triticum and in the A genome of multiple wheat accessions, which revealed that TaWAK7 orthologs underwent complex evolution with frequent gene fusion and domain deletion. In addition, three cytoplasmic proteins interacting with TaWAK7 were indicated by yeast-two-hybrid and BiFC assays. Binding of TaWAK7 with these proteins could change the subcellular localization of TaWAK7 from the plasma membrane to the cytoplasm. This study provides a better understanding of the evolution of WAKs at the genomic level and TaWAK7 at the gene level, and provides useful clues for further investigation of how WAKs transmit the extracellular signals to the cytoplasm to activate defense responses.
ABSTRACT
In recent years, breakthroughs in bioinformatics have been made with the discovery of many functionally significant non-coding RNAs (ncRNAs). The discovery of these ncRNAs has further demonstrated the multi-level characteristics of intracellular gene expression regulation, which plays an important role in assisting diagnosis, guiding clinical drug use and determining prognosis in the treatment process of various diseases. microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs) are the three major types of ncRNAs that interact with each other. Studies have shown that lncRNAs and circRNAs can sponge miRNAs, thereby influencing normal physiological processes and regulating mRNA expression and, thus, the physiological state of cells. This paper summarizes the mechanism of action and research progress of the three ncRNA and seven types of modalities. This summary is intended to provide new ideas for diagnosing and treating diseases and researching and developing new drugs.
Subject(s)
MicroRNAs , RNA, Long Noncoding , MicroRNAs/genetics , RNA, Circular/genetics , RNA, Long Noncoding/genetics , Gene Expression Regulation , Computational BiologyABSTRACT
KEY MESSAGE: A new functional Pm21 haplotype, Pm21(8#), was cloned from the new wheat-H. villosa translocation line T6VS(8#)·6DL, which confers the same strong resistance to powdery mildew through a different resistance mechanism. Broad-spectrum disease resistance genes are desirable in crop breeding for conferring stable, durable resistance in field production. Pm21(4#) is a gene introduced from wild Haynaldia villosa into wheat that confers broad-spectrum resistance to wheat powdery mildew and has been widely used in wheat production for approximately 30 years. The discovery and transfer of new functional haplotypes of Pm21 into wheat will expand its genetic diversity in production and avoid the breakdown of resistance conferred by a single gene on a large scale. Pm21(4#) previously found from T6VS(4#)·6AL has been cloned. In this study, a new wheat-H. villosa translocation, T6VS(8#)·6DL, was identified. A new functional Pm21 haplotype, designated Pm21(8#), was cloned and characterized. The genomic structures and the splicing patterns of Pm21(4#) and Pm21(8#) were different, and widespread sequence diversity was observed in the gene coding region and the promoter region. In the field, Pm21(8#) conferred resistance to Blumeria graminis f. sp. tritici (Bgt), similar to Pm21(4#), indicating that Pm21(8#) was also a resistance gene. However, Bgt development during the infection stage was obviously different between Pm21(4#)- and Pm21(8#)-containing materials under the microscopic observation. Pm21(4#) inhibited the formation of haustoria and the development of hyphae in the initial infection stage, while Pm21(8#) limited the growth of hyphae and inhibited the formation of conidiophores in the late infection stage. Therefore, Pm21(8#) is a new functional Pm21 haplotype that provides a new gene resource for wheat breeding.
Subject(s)
Plant Breeding , Triticum , Triticum/genetics , Triticum/metabolism , Haplotypes , Poaceae/genetics , Genetic Variation , Disease Resistance/genetics , Plant Diseases/geneticsABSTRACT
KEY MESSAGE: The novel wheat powdery mildew and stripe rust resistance genes Pm5V/Yr5V are introgressed from Dasypyrum villosum and fine mapped to a narrowed region in 5VS, and their effects on yield-related traits were characterized. The powdery mildew and stripe rust seriously threaten wheat production worldwide. Dasypyrum villosum (2n = 2x = 14, VV), a relative of wheat, is a valuable resource of resistance genes for wheat improvement. Here, we describe a platform for rapid introgression of the resistance genes from D. villosum into the wheat D genome. A complete set of new wheat-D. villosum V (D) disomic substitution lines and 11 D/V Robertsonian translocation lines are developed and characterized by molecular cytogenetic method. A new T5DL·5V#5S line NAU1908 shows resistance to both powdery mildew and stripe rust, and the resistances associated with 5VS are confirmed to be conferred by seedling resistance gene Pm5V and adult-plant resistance gene Yr5V, respectively. We flow-sort chromosome arm 5VS and sequence it using the Illumina NovaSeq 6000 system that allows us to generate 5VS-specific markers for genetic mapping of Pm5V/Yr5V. Fine mapping shows that Pm5V and Yr5V are closely linked and the location is narrowed to an approximately 0.9 Mb region referencing the sequence of Chinese Spring 5DS. In this region, a NLR gene in scaffold 24,874 of 5VS orthologous to TraesCS5D02G044300 is the most likely candidate gene for Pm5V. Soft- and hard-grained T5DL·5V#5S introgressions confer resistance to both powdery mildew and stripe rust in diverse wheat genetic backgrounds without yield penalty. Meanwhile, significant decrease in plant height and increase in yield were observed in NIL-5DL·5V#5S compared with that in NIL-5DL·5DS. These results indicate that Pm5V/Yr5V lines might have the potential value to facilitate wheat breeding for disease resistance.
Subject(s)
Basidiomycota , Triticum , Disease Resistance/genetics , Plant Breeding , Plant Diseases/genetics , Poaceae/genetics , Triticum/geneticsABSTRACT
Objective: To investigate the willingness of Ganzhou residents to participate in "Internet + Nursing services" and analyse the relevant influencing factors. Methods: From May to June 2021, 426 Ganzhou residents were surveyed using an Internet + Nursing services questionnaire and the relevant influencing factors were analysed. The questionnaire comprised two parts: demographic characteristic section and a questionnaire on residents' willingness to participate in Internet + Nursing services including for dimensions (awareness, participation, trust and need), a 5-point Likert scale was used. Results: A total of 397 valid questionnaires were recovered, and the total willingness of Ganzhou residents to participate in the service was derived as 11.59 ± 2.14. The results of multiple linear regression analyses showed that the presence of family members with a chronic disease or mobility difficulties, and an awareness and trust of Internet + Nursing services were influencing factors of residents' participation willingness (P < 0.05). Conclusion: The participation willingness of Ganzhou residents in Internet + Nursing services is modestly low, and the reasons for participation varied. It is suggested that the government and pilot hospitals strengthen the publicity surrounding these services, improve safety measures, strengthen team training, and develop products suitable for the elderly to increase residents' participation willingness.
ABSTRACT
BACKGROUND: To provide an economical and practical defibrillator for first aid teaching and training, to reduce the cost of teaching and training, increase teaching and training equipment, provide trainees with more hands-on training sessions, and improve first aid capabilities. METHODS: Developing a special teaching defibrillator with the same structure and operation configuration as the clinical medical emergency defibrillator. The appearance, structure and operating accessories of the two defibrillators are the same. The difference between the defibrillator and the clinical medical emergency defibrillator are as follows: the clinical medical emergency defibrillator can be energized, and there are expensive electronic accessories and defibrillation accessories for charging and discharging in the machine. When discharging, the electrode plate has current discharged into the human body; the power plug of the "special defibrillator for teaching and training" is a fake plug. When the power is plugged in, no current enters the body and the machine. There are no expensive electronic accessories and defibrillation accessories for charging and discharging, and no current is discharged during discharge. Then compare the teaching effect of the special defibrillator for teaching and training and the clinical medical emergency defibrillator (including operation score and attitude after training). RESULTS: The scores of defibrillator operation in the experimental group of junior college students (87.77 ± 4.11 vs. 83.30 ± 4.56, P < 0.001) and the experimental group of undergraduate students (90.40 ± 3.67 vs. 89.12 ± 3.68, P = 0.011) were higher than those in the corresponding control group; The attitude of junior college students in the experimental group and undergraduate students in the experimental group after training was more positive than that of the corresponding control group (P < 0.05). CONCLUSIONS: The special defibrillator for teaching and training can save the purchase cost of teaching equipment, increase teaching and training resources, and improve the trainee's defibrillation ability, defibrillation confidence and defibrillation security.
Subject(s)
Cardiology/education , Defibrillators , Education, Medical/methods , Electric Countershock/standards , Students, Medical , Teaching/organization & administration , Adolescent , Adult , Female , Humans , Male , Young AdultABSTRACT
BACKGROUND: Nucleotide-binding and leucine-rich repeat (NLR) genes have attracted wide attention due to their crucial role in protecting plants from pathogens. SMRT-RenSeq, combining PacBio sequencing after resistance gene enrichment sequencing (RenSeq), is a powerful method for selectively capturing and sequencing full-length NLRs. Haynaldia villosa, a wild grass species with a proven potential for wheat improvement, confers resistance to multiple diseases. So, genome-wide identification of the NLR gene family in Haynaldia villosa by SMRT-RenSeq can facilitate disease resistance genes exploration. RESULTS: In this study, SMRT-RenSeq was performed to identify the genome-wide NLR complement of H. villosa. In total, 1320 NLRs were annotated in 1169 contigs, including 772 complete NLRs. All the complete NLRs were phylogenetically analyzed and 11 main clades with special characteristics were derived. NLRs could be captured with high efficiency when aligned with cloned R genes, and cluster expansion in some specific gene loci was observed. The physical location of NLRs to individual chromosomes in H. villosa showed a perfect homoeologous relationship with group 1, 2, 3, 5 and 6 of other Triticeae species, however, NLRs physically located on 4VL were largely in silico predicted to be located on the homoeologous group 7. Fifteen types of integrated domains (IDs) were integrated in 52 NLRs, and Kelch and B3 NLR-IDs were found to have expanded in H. villosa, while DUF948, NAM-associated and PRT_C were detected as unique integrated domains implying the new emergence of NLR-IDs after H. villosa diverged from other species. CONCLUSION: SMRT-RenSeq is a powerful tool to identify NLR genes from wild species using the baits of the evolutionary related species with reference sequences. The availability of the NLRs from H. villosa provide a valuable library for R gene mining and transfer of disease resistance into wheat.
Subject(s)
Disease Resistance , NLR Proteins , Plant Diseases , Plant Proteins/genetics , Poaceae , Disease Resistance/genetics , Multigene Family , NLR Proteins/genetics , Phylogeny , Plant Diseases/genetics , Poaceae/genetics , TriticumABSTRACT
Genomics studies in wild species of wheat have been limited due to the lack of references; however, new technologies and bioinformatics tools have much potential to promote genomic research. The wheat-Haynaldia villosa translocation line T6VS·6AL has been widely used as a backbone parent of wheat breeding in China. Therefore, revealing the genome structure of translocation chromosome 6VS·6AL will clarify how this chromosome formed and will help to determine how it affects agronomic traits. In this study, chromosome flow sorting, NGS sequencing and Chicago long-range linkage assembly were innovatively used to produce the assembled sequences of 6VS·6AL, and gene prediction and genome structure characterization at the molecular level were effectively performed. The analysis discovered that the short arm of 6VS·6AL was actually composed of a large distal segment of 6VS, a small proximal segment of 6AS and the centromere of 6A, while the collinear region in 6VS corresponding to 230-260 Mb of 6AS-Ta was deleted when the recombination between 6VS and 6AS occurred. In addition to the molecular mechanism of the increased grain weight and enhanced spike length produced by the translocation chromosome, it may be correlated with missing GW2-V and an evolved NRT-V cluster. Moreover, a fine physical bin map of 6VS was constructed by the high-throughput developed 6VS-specific InDel markers and a series of newly identified small fragment translocation lines involving 6VS. This study will provide essential information for mining of new alien genes carried by the 6VS·6AL translocation chromosome.
Subject(s)
Plant Breeding , Triticum , Chromosomes, Plant/genetics , Poaceae/genetics , Translocation, Genetic , Triticum/geneticsABSTRACT
Barley possesses a branchless, spike-shaped inflorescence where determinate spikelets attach directly to the main axis, but the developmental mechanism of spikelet identity remains largely unknown. Here we report the functional analysis of the barley gene BRANCHED AND INDETERMINATE SPIKELET 1 (BDI1), which encodes a TCP transcription factor and plays a crucial role in determining barley inflorescence architecture and spikelet development. The bdi1 mutant exhibited indeterminate spikelet meristems that continued to grow and differentiate after producing a floret meristem; some spikelet meristems at the base of the spike formed two fully developed seeds or converted to branched spikelets, producing a branched inflorescence. Map-based cloning analysis showed that this mutant has a deletion of ~600 kb on chromosome 5H containing three putative genes. Expression analysis and virus-induced gene silencing confirmed that the causative gene, BDI1, encodes a CYC/TB1-type TCP transcription factor and is highly conserved in both wild and cultivated barley. Transcriptome and regulatory network analysis demonstrated that BDI1 may integrate regulation of gene transcription cell wall modification and known trehalose-6-phosphate homeostasis to control spikelet development. Together, our findings reveal that BDI1 represents a key regulator of inflorescence architecture and meristem determinacy in cereal crop plants.
Subject(s)
Hordeum , Meristem , Gene Expression Regulation, Plant , Hordeum/genetics , Hordeum/metabolism , Meristem/genetics , Meristem/metabolism , Mutation , Plant Proteins/genetics , Plant Proteins/metabolism , Transcription Factors/genetics , Transcription Factors/metabolismABSTRACT
NACs are important transcriptional factors involved in growth and development as well as responses to abiotic and biotic stresses in plants. In this study, TaNAC6 was identified as a differentially expressed gene between two lines with broad-spectrum resistance to powdery mildew, NAU9918 and OEStpk-V, and their corresponding susceptible isogenic lines, SM-1 and Yangmai158, after Bgt inoculation by transcriptome analysis. Then, three homoeologous genes of TaNAC6 were cloned and named as TaNAC6-A, TaNAC6-B and TaNAC6-D, respectively. Each member of TaNAC6s was subcellular localized to the nucleus and displayed the transcriptional activation activity. However, the responses of them to pathogens and phytohormones were different. Transient overexpression of each TaNAC6 reduced the haustorium index of Yangmai158, and stable transformation of TaNAC6-A enhanced its resistance against Bgt, implying that TaNAC6s play important roles in basal resistance. Silencing of TaNAC6s compromised the resistance of OEStpk-V and NAU9918 suggesting that TaNAC6s play positive roles in the broad-spectrum resistance against Bgt. TaNAC6s might be induced by JA and then feedback regulate the JA pathway leading to improved resistance to Bgt. The role of TaNAC6s and their orthologous genes HvNAC6 and ATAF1 in the powdery mildew resistance implied these NAC6 genes share a common signal pathway across species.
Subject(s)
Ascomycota/pathogenicity , Plant Diseases/microbiology , Triticum/metabolism , Triticum/microbiology , Cell Nucleus/metabolism , Cell Nucleus/microbiology , Gene Expression Profiling , Plant Growth Regulators/metabolism , Signal TransductionABSTRACT
KEY MESSAGE: Pm62, a novel adult-plant resistance (APR) gene against powdery mildew, was transferred from D. villosum into common wheat in the form of Robertsonian translocation T2BS.2VL#5. Powdery mildew, which is caused by the fungus Blumeria graminis f. sp. tritici, is a major disease of wheat resulting in substantial yield and quality losses in many wheat production regions of the world. Introgression of resistance from wild species into common wheat has application for controlling this disease. A Triticum durum-Dasypyrum villosum chromosome 2V#5 disomic addition line, N59B-1 (2n = 30), improved resistance to powdery mildew at the adult-plant stage, which was attributable to chromosome 2V#5. To transfer this resistance into bread wheat, a total of 298 BC1F1 plants derived from the crossing between N59B-1 and Chinese Spring were screened by combined genomic in situ hybridization and fluorescent in situ hybridization, 2V-specific marker analysis, and reaction to powdery mildew to confirm that a dominant adult-plant resistance gene, designated as Pm62, was located on chromosome 2VL#5. Subsequently, the 2VL#5 (2D) disomic substitution line (NAU1825) and the homozygous T2BS.2VL#5 Robertsonian translocation line (NAU1823), with normal plant vigor and full fertility, were identified by molecular and cytogenetic analyses of the BC1F2 generation. The effects of the T2BS.2VL#5 recombinant chromosome on agronomic traits were also evaluated in the F2 segregation population. The results suggest that the translocated chromosome may have no distinct effect on plant height, 1000-kernel weight or flowering period, but a slight effect on spike length and seeds per spike. The translocation line NAU1823 has being utilized as a novel germplasm in breeding for powdery mildew resistance, and the effects of the T2BS.2VL#5 recombinant chromosome on yield-related and flour quality characters will be further assessed.
Subject(s)
Disease Resistance/genetics , Genes, Plant , Plant Diseases/genetics , Poaceae/genetics , Triticum/genetics , Ascomycota/pathogenicity , Chromosomes, Plant/genetics , Genes, Dominant , Genetic Markers , In Situ Hybridization, Fluorescence , Plant Diseases/microbiology , Translocation, Genetic , Triticum/microbiologyABSTRACT
Pattern recognition receptors (PRRs) can trigger plant immunity through the recognition of pathogen-associated molecular patterns. In this study, we report that a malectin-like/leucine-rich repeat receptor protein kinase gene, RLK-V, from Haynaldia villosa putatively acts as a PRR to positively regulate powdery mildew resistance caused by Blumeria graminis f. sp. tritici (Bgt) in wheat. RLK-V has two alternatively spliced transcripts corresponding to an intact RLK-V1.1 and a truncated RLK-V1.2 caused by intron retention. Expression analysis showed that both transcripts could be up-regulated by Bgt in resistant materials, whereas the functional RLK-V1.1 was expressed only after Bgt inoculation. Promoter activity assays indicated that RLK-V could respond to Bgt even in susceptible wheat. Silencing of RLK-V in Pm21-carrying resistant materials resulted in compromised resistance to Bgt. In addition, over-expression of RLK-V1.1 in Pm21-lacking susceptible Yangmai158 and SM-1 by single-cell transient expression and stable transformation in Yangmai158 could improve powdery mildew resistance. We propose that RLK-V regulates basal resistance to powdery mildew, which is also required for broad-spectrum resistance mediated by the Pm21 gene. Over-expression of RLK-V1.1 could trigger cell death in Nicotiana benthamiana, and RLK-V1.1 transgenic wheat accumulated more reactive oxygen species and displayed a stronger hypersensitive response than did the recipient, which led to enhanced Bgt resistance. However, constitutive activation of RLK-V1.1 resulted in the abnormal growth of transgenic plants.