Construction of a high-quality yeast two-hybrid (Y2H) library and its application in identification of interacting proteins with key vernalization regulator TaVRN-A1 in wheat

BACKGROUND: Low temperature is required for the competence of winter wheat to flowering (vernalization), and several key components in the vernalization-mediated flowering pathway have been isolated. A Y2H library is a very useful platform to further unravel novel regulators in the flowering pathway. Thus, there is a necessity to construct a high-quality Y2H library using vernalized winter wheat plants. RESULT: We described the construction of a high-quality Y2H library using winter wheat plants with cold-treatment for different weeks to maximize pooling interacting proteins during vernalization. The resultant Y2H library contained ~2.5×10(6) independent clones, with a cell density of ~2.6×10(8) and an average insert size of ~ 1.5 kb. TaVRN-A1 was used as a “bait” to test the quality of the Y2H library. As a result, several cDNA clones encoding TaSOC1 and TaSVP1 that were known to have a direct binding with TaVRN-A1 were identified, demonstrating that the Y2H screen system constructed in this study was highly efficient. Additional proteins that were discovered but not characterized in previous studies could be novel partners of TaVRN-A1 in wheat. CONCLUSION: We established a high-efficient Y2H screen system using the Matchmaker™ technology with several modifications in the critical steps. Ultimately, we provided a successful example to fast and economically create high-quality Y2H libraries for studies on protein interaction in hexaploid wheat

Anatomical variations of the ethmoid sinuses and their association with health or pathology of the ethmoid and maxillary sinuses in a Southern Chinese population: An analysis using cone-beam computed tomography.

Purpose The aim of this study was to evaluate the prevalence of clinically relevant anatomical variations of the ethmoid sinuses and their potential association with ethmoid and maxillary sinus pathologies on cone-beam computed tomography (CBCT) scans. Additionally, potential associations with different sides and demographic factors, including age and sex, were evaluated. Materials and Methods In total, 273 CBCT scans with complete ethmoid and maxillary sinuses were analyzed to determine the prevalence of Agger nasi cell, supraorbital ethmoid cell, Haller cell, Onodi cell, and ethmomaxillary sinus. In addition, the health or pathology of the ethmoid and maxillary sinuses was also recorded to assess correlations with the aforementioned variations. Results The prevalence of Agger nasi cell was found to be the highest (95.6%) in this study, followed by Onodi cell (60.4%), Haller cell (29.3%), and supraorbital ethmoid cell (19.4%). Ethmomaxillary sinus was the least common finding (16.5%). Males and persons above 61 years of age had a significantly higher frequency of supraorbital ethmoid cell and Onodi cell, respectively. However, no significant relationships were noted between anatomical variations of the ethmoid sinus and pathologies of the ethmoid or maxillary sinus. Conclusion There was a high prevalence of ethmoid sinus variations in this Southern Chinese population. The prevalence of Agger nasi cell and Onodi cell was higher than that of other anatomical variations of the ethmoid sinuses. Anatomical variations of the ethmoid sinuses were not associated with ethmoid or maxillary sinus pathologies in this patient cohort

Clonado posicional de los genes de vernalización de trigo

Con el objetivo de llegar a un mayor entendimiento del mecanismo del proceso de vernalización y su interacción con otros factores ambientales en la determinación del momento de floración en el trigo se planteó como primer paso el aislamiento de los genes Vrn1 y Vrn2 utilizando como estrategia el clonado posicional. El clonado mediante caminata cromosómica en el trigo reviste cierta complejidad debido al gran tamaño del genoma (5.600 Mb en el genoma haploide de Triticum monoccum, AmAm, y 16.000 Mb en el de T. aestivum, AABBDD) y la abundancia de elementos repetitivos. A fin de disminuir la probabilidad de que estos elementos repetitivos detuvieran la caminata, tanto para el clonado de Vrn1 como el de Vrn2, se utilizaron las regiones ortólogas de arroz, cebada y sorgo como puntos de apoyo para superar estas regiones genómicas. En este artículo se resumen los logros alcanzados en el clonado posicional de Vrn1 y Vrn2 y se plantea un modelo para explicar a nivel molecular las interacciones entre estos genes.Academia Nacional de Agronomía y Veterinari

Clonado posicional de los genes de vernalización de trigo

Con el objetivo de llegar a un mayor entendimiento del mecanismo del proceso de vernalización y su interacción con otros factores ambientales en la determinación del momento de floración en el trigo se planteó como primer paso el aislamiento de los genes Vrn1 y Vrn2 utilizando como estrategia el clonado posicional. El clonado mediante caminata cromosómica en el trigo reviste cierta complejidad debido al gran tamaño del genoma (5.600 Mb en el genoma haploide de Triticum monoccum, AmAm, y 16.000 Mb en el de T. aestivum, AABBDD) y la abundancia de elementos repetitivos. A fin de disminuir la probabilidad de que estos elementos repetitivos detuvieran la caminata, tanto para el clonado de Vrn1 como el de Vrn2, se utilizaron las regiones ortólogas de arroz, cebada y sorgo como puntos de apoyo para superar estas regiones genómicas. En este artículo se resumen los logros alcanzados en el clonado posicional de Vrn1 y Vrn2 y se plantea un modelo para explicar a nivel molecular las interacciones entre estos genes.Academia Nacional de Agronomía y Veterinari

Integrated transcriptomic and pathway analyses of sorghum plants revealed the molecular mechanisms of host defense against aphids

Sugarcane aphid has emerged as a major pest of sorghum recently, and a few sorghum accessions were identified for resistance to this aphid so far. However, the molecular and genetic mechanisms underlying this resistance are still unclear. To understand these mechanisms, transcriptomics was conducted in resistant Tx2783 and susceptible BTx623 sorghum genotypes infested with sugarcane aphids. A principal component analysis revealed differences in the transcriptomic profiles of the two genotypes. The pathway analysis of the differentially expressed genes (DEGs) indicated the upregulation of a set of genes related to signal perception (nucleotide-binding, leucine-rich repeat proteins), signal transduction [mitogen-activated protein kinases signaling, salicylic acid (SA), and jasmonic acid (JA)], and plant defense (transcription factors, flavonoids, and terpenoids). The upregulation of the selected DEGs was verified by real-time quantitative PCR data analysis, performed on the resistant and susceptible genotypes. A phytohormone bioassay experiment showed a decrease in aphid population, plant mortality, and damage in the susceptible genotype when treated with JA and SA. Together, the results indicate that the set of genes, pathways, and defense compounds is involved in host plant resistance to aphids. These findings shed light on the specific role of each DEG, thus advancing our understanding of the genetic and molecular mechanisms of host plant resistance to aphids

Clonado posicional de los genes de vernalización de trigo

Con el objetivo de llegar a un mayor entendimiento del mecanismo del proceso de vernalización y su interacción con otros factores ambientales en la determinación del momento de floración en el trigo se planteó como primer paso el aislamiento de los genes Vrn1 y Vrn2 utilizando como estrategia el clonado posicional. El clonado mediante caminata cromosómica en el trigo reviste cierta complejidad debido al gran tamaño del genoma (5.600 Mb en el genoma haploide de Triticum monoccum, AmAm, y 16.000 Mb en el de T. aestivum, AABBDD) y la abundancia de elementos repetitivos. A fin de disminuir la probabilidad de que estos elementos repetitivos detuvieran la caminata, tanto para el clonado de Vrn1 como el de Vrn2, se utilizaron las regiones ortólogas de arroz, cebada y sorgo como puntos de apoyo para superar estas regiones genómicas. En este artículo se resumen los logros alcanzados en el clonado posicional de Vrn1 y Vrn2 y se plantea un modelo para explicar a nivel molecular las interacciones entre estos genes.Academia Nacional de Agronomía y Veterinari

The USDA Barley Core Collection:Genetic Diversity, Population Structure, and Potential for Genome-Wide Association Studies

New sources of genetic diversity must be incorporated into plant breeding programs if they are to continue increasing grain yield and quality, and tolerance to abiotic and biotic stresses. Germplasm collections provide a source of genetic and phenotypic diversity, but characterization of these resources is required to increase their utility for breeding programs. We used a barley SNP iSelect platform with 7,842 SNPs to genotype 2,417 barley accessions sampled from the USDA National Small Grains Collection of 33,176 accessions. Most of the accessions in this core collection are categorized as landraces or cultivars/breeding lines and were obtained from more than 100 countries. Both STRUCTURE and principal component analysis identified five major subpopulations within the core collection, mainly differentiated by geographical origin and spike row number (an inflorescence architecture trait). Different patterns of linkage disequilibrium (LD) were found across the barley genome and many regions of high LD contained traits involved in domestication and breeding selection. The genotype data were used to define 'mini-core' sets of accessions capturing the majority of the allelic diversity present in the core collection. These 'mini-core' sets can be used for evaluating traits that are difficult or expensive to score. Genome-wide association studies (GWAS) of 'hull cover', 'spike row number', and 'heading date' demonstrate the utility of the core collection for locating genetic factors determining important phenotypes. The GWAS results were referenced to a new barley consensus map containing 5,665 SNPs. Our results demonstrate that GWAS and high-density SNP genotyping are effective tools for plant breeders interested in accessing genetic diversity in large germplasm collections

Precisely mapping a major gene conferring resistance to Hessian fly in bread wheat using genotyping-by-sequencing

Background: One of the reasons hard red winter wheat cultivar 'Duster' (PI 644016) is widely grown in the southern Great Plains is that it confers a consistently high level of resistance to biotype GP of Hessian fly (Hf). However, little is known about the genetic mechanism underlying Hf resistance in Duster. This study aimed to unravel complex structures of the Hf region on chromosome 1AS in wheat by using genotyping-by-sequencing (GBS) markers and single nucleotide polymorphism (SNP) markers.Results: Doubled haploid (DH) lines generated from a cross between two winter wheat cultivars, 'Duster' and 'Billings', were used to identify genes in Duster responsible for effective and consistent resistance to Hf. Segregation in reaction of the 282 DH lines to Hf biotype GP fit a one-gene model. The DH population was genotyped using 2,358 markers developed using the GBS approach. A major QTL, explaining 88% of the total phenotypic variation, was mapped to a chromosome region that spanned 178 cM and contained 205 GBS markers plus 1 SSR marker and 1 gene marker, with 0.86 cM per marker in genetic distance. The analyses of GBS marker sequences and further mapping of SSR and gene markers enabled location of the QTL-containing linkage group on the short arm of chromosome 1A. Comparative mapping of the common markers for the gene for QHf.osu-1A d in Duster and the Hf-resistance gene for QHf.osu-1A 74 in cultivar '2174' showed that the two Hf resistance genes are located on the same chromosome arm 1AS, only 11.2 cM apart in genetic distance. The gene at QHf.osu-1A d in Duster has been delimited within a 2.7 cM region.Conclusion: Two distinct resistance genes exist on the short arm of chromosome 1A as found in the two hard red winter cultivars, 2174 and Duster. Whereas the Hf resistance gene in 2174 is likely allelic to one or more of the previously mapped resistance genes (H9, H10, H11, H16, or H17) in wheat, the gene in Duster is novel and confers a more consistent phenotype than 2174 in response to biotype GP infestation in controlled-environment assays.Peer reviewedPlant and Soil Science