Detection of Favorable QTL Alleles and Candidate Genes for Lint Percentage by GWAS in Chinese Upland Cotton

Improving cotton yield is a major breeding goal for Chinese upland cotton. Lint percentage is an important yield component and a critical economic index for cotton cultivars, and raising the lint percentage has a close relationship to improving cotton lint yield. To investigate the genetic architecture of lint percentage, a diversity panel consisting of 355 upland cotton accessions was grown, and the lint percentage was measured in four different environments. Genotyping was performed with specific-locus amplified fragment sequencing (SLAF-seq). Twelve single-nucleotide polymorphisms (SNPs) associated with lint percentage were detected via a genome-wide association study (GWAS), in which five SNP loci distributed on chromosomes At3 (A02) and At4 (A08) and contained two major-effect QTLs, which were detected in the best linear unbiased predictions (BLUPs) and in more than three environments simultaneously. Furthermore, favorable haplotypes (FHs) of two major-effect QTLs and 47 putative candidate genes in the two linkage disequilibrium (LD) blocks of these associated loci were identified. The expression levels of these putative candidate genes were estimated using RNA-seq data from ten upland cotton tissues. We found that Gh_A02G1268 was very highly expressed during the early fiber development stage, whereas the gene was poorly expressed in the seed. These results implied that Gh_A02G1268 may determine the lint percentage by regulating seed and fiber development. The favorable QTL alleles and candidate genes for lint percentage identified in this study will have high potential for improving lint yield in future Chinese cotton breeding programs

Identification, Expression, and Functional Analysis of the Group IId WRKY Subfamily in Upland Cotton (Gossypium hirsutum L.)

WRKY transcription factors have diverse functions in regulating stress response, leaf senescence, and plant growth and development. However, knowledge of the group IId WRKY subfamily in cotton is largely absent. This study identified 34 group IId WRKY genes in the Gossypium hirsutum genome, and their genomic loci were investigated. Members clustered together in the phylogenetic tree had similar motif compositions and gene structural features, revealing similarity and conservation within group IId WRKY genes. During the evolutionary process, 14 duplicated genes appeared to undergo purification selection. Public RNA-seq data were used to examine the expression patterns of group IId WRKY genes in various tissues and under drought and salt stress conditions. Ten highly expressed genes were identified, and the ten candidate genes revealed distinct expression patterns under drought and salt treatments by qRT-PCR analysis. Among them, Gh_A11G1801 was used for functional characterization. GUS activity was differentially induced by various stresses in Gh_A11G1801p::GUS transgenic Arabidopsis plants. The virus-induced gene silencing (VIGS) of Gh_A11G1801 resulted in drought sensitivity in cotton plants, which was accompanied by elevated malondialdehyde (MDA) content and reduced catalase (CAT) content. Taken together, these findings obtained in this study provide valuable resources for further studying group IId WRKY genes in cotton. Our results also enrich the gene resources for the genetic improvements of cotton varieties that are suitable for growth in stressful conditions

Untersuchungen uber das Schicksal der in rohes und gekochtes Brunnenwasser gemischten pathogenen Bakterien

Der Verfasser hat Untersuchungen uber die Lebensdauer von pathogenen Darmbakterien, die in rohes und gekochtes Brunnenwasser gemischt wurden, durchgefuhrt. Er hat 5 Brunnenwasser untersucht mit B. typhosus, B. paratyphosus A u. B, B. dysenteriae Komagome A u. B, B. dysenteriae Shiga; die Stamme erhielt Verf. aus dem Staatlichen Institut fur Infektionskrankheiten und aus dem bakteriologischen Institut zu Chiba. Die Ergebnisse sind folgende: 1) war die Menge der verwandten Bakterien klein (ca. 1/3000 Ose in 10 cc.), lebten alle Bakterien in rohem Wasser langer als in gekochtem Wasser. 2) war die Bakterienmenge relativ gross (1 Ose in 10 cc.), lebten die Bakterien zwar langer als bei geringer Menge, verschwanden aber in rohem Wasser schneller als in gekochtem. 3) Unter beiden Versuchsanordnungen lebten die Bakterien im Brunnenwasser langer als in Aq. dest. oder in physiologischer Kochsalzlosung. 4) Die Tabellen zeigen kurz die Ergebnisse: (Autoreferat

Characterization and Functional Analysis of GhNAC82, A NAM Domain Gene, Coordinates the Leaf Senescence in Upland Cotton (Gossypium hirsutum L.)

In the process of growth and development, cotton exhibits premature senescence under various abiotic stresses, impairing yield and fiber quality. NAC (NAM, ATAF1,2, and CUC2) protein widely distributed in land plants, play the critical role in responding to abiotic stress and regulating leaf senescence. We have identified and functional analyzed a NAM domain gene GhNAC82 in upland cotton, it was located on the A11 chromosome 4,921,702 to 4,922,748 bp, only containing one exon. The spatio-temporal expression pattern analysis revealed that it was highly expressed in root, torus, ovule and fiber development stage. The results of qRT-PCR validated that GhNAC82 negatively regulated by salt stress, drought stress, H2O2 stress, IAA treatment, and ethylene treatment, positively regulated by the ABA and MeJA treatment. Moreover, heterologous overexpression of GhNAC82 results in leaf premature senescence and delays root system development in Arabidopsis thaliana. The phenotype of delayed-senescence was performed after silencing GhNAC82 by VIGS in premature cotton. Taken together, GhNAC82 was involved in different abiotic stress pathways and play important roles in negatively regulating leaf premature senescence

Transcriptome analysis of nitric oxide-responsive genes in upland cotton (<i>Gossypium hirsutum</i>)

<div><p>Nitric oxide (NO) is an important signaling molecule with diverse physiological functions in plants. It is therefore important to characterize the downstream genes and signal transduction networks modulated by NO. Here, we identified 1,932 differentially expressed genes (DEGs) responding to NO in upland cotton using high throughput tag sequencing. The results of quantitative real-time polymerase chain reaction (qRT-PCR) analysis of 25 DEGs showed good consistency. Gene Ontology (GO) and KEGG pathway were analyzed to gain a better understanding of these DEGs. We identified 157 DEGs belonging to 36 transcription factor (TF) families and 72 DEGs related to eight plant hormones, among which several TF families and hormones were involved in stress responses. Hydrogen peroxide and malondialdehyde (MDA) contents were increased, as well related genes after treatment with sodium nitroprusside (SNP) (an NO donor), suggesting a role for NO in the plant stress response. Finally, we compared of the current and previous data indicating a massive number of NO-responsive genes at the large-scale transcriptome level. This study evaluated the landscape of NO-responsive genes in cotton and identified the involvement of NO in the stress response. Some of the identified DEGs represent good candidates for further functional analysis in cotton.</p></div

Co-doped ZnO dilute magnetic semiconductor thin films by pulsed laser deposition: Excellent transmittance, low resistivity and high mobility

Co-doped ZnO ceramic samples sintered at four different temperatures were prepared by solid-state reaction method and implanted by Al ions subsequently. The microstructural, defect, magnetic and electrical properties of the samples were systematically investigated by x-ray diffraction, micro-Raman spectroscope, vibrating sample magnetometer and Hall measurement, respectively. The results show that all the samples exhibit room-temperature ferromagnetism with a saturation magnetization of 0.02–0.03 emu g−1, the value of which is affected by the sintering temperature. The origin of room-temperature ferromagnetism is considered as the formation of Co2+– V O–Co2+ bound magnetic polarons. Even though the implantation of Al3+ slightly reduces the saturation magnetization because of the lattice damage, less V O and larger lattice spacing, however, an appropriate amount of Al3+ implantation and a proper sintering temperature can remarkably improve the electrical properties with the mobility of 200 ∼300 cm2 Vs−1 and the resistivity of 20 ∼40 Ω cm. In general, samples sintered at 1200∘C present more excellent comprehensive performances

Insights into the Genomic Regions and Candidate Genes of Senescence-Related Traits in Upland Cotton via GWAS

Senescence is the last stage of plant development and is controlled by both internal and external factors. Premature senescence significantly affects the yield and quality of cotton. However, the genetic architecture underlying cotton senescence remains unclear. In this study, genome-wide association studies (GWAS) were performed based on 3,015,002 high-quality SNP markers from the resequencing data of 355 upland cotton accessions to detect genomic regions for cotton senescence. A total of 977 candidate genes within 55 senescence-related genomic regions (SGRs), SGR1–SGR55, were predicted. Gene ontology (GO) analysis of candidate genes revealed that a set of biological processes was enriched, such as salt stress, ethylene processes, and leaf senescence. Furthermore, in the leaf senescence GO term, one candidate gene was focused on: Gohir.A12G270900 (GhMKK9), located in SGR36, which encodes a protein of the MAP kinase kinase family. Quantitative real-time PCR (qRT-PCR) analysis showed that GhMKK9 was up-regulated in old cotton leaves. Overexpression of GhMKK9 in Arabidopsis accelerated natural leaf senescence. Virus-induced gene silencing (VIGS) of GhMKK9 in cotton increased drought tolerance. These results suggest that GhMKK9 is a positive regulator and might be involved in drought-induced senescence in cotton. The results provide new insights into the genetic basis of cotton senescence and will be useful for improving cotton breeding in the future

Experimental Study of the Formation and Evolution of Gas Jets in Supersonic Combustion Chambers

A simple and efficient flow field visualization method (based on shadow imaging) was applied in a direct-connect test to explore the influence of the momentum flux ratio and the jet angle on the formation and evolution of nitrogen jets in supersonic combustion chambers. The test setup adopts a rectangular flow passage to simulate a flight condition with Mach number of 6 and altitude of 25 km. The experimental results showed that (a) the flow field visualization method adopted in this paper can clearly register the formation and evolution of the shock wave structure in the flow field and the windward shear vortex on the jet surface. (b) The evolution process of the windward shear vortex is significantly affected by the jet angle. In particular, the stretching position of the windward shear vortex changed when the jet angle was obtuse. (c) The bow shocks showed local distortion due to the periodic generation of large-scale shear vortexes. (d) Under the working conditions of the test, the largest instability of the flow field was found for a jet angle of 120&deg;. This work provides, on one hand, the experimental basis for clarifying the formation and evolution mechanism of transverse gas jets, and on the other, valuable data that can be used to validate numerical simulations