Project description:Background: Common bacterial blight (CBB) caused by Xanthomonas phaseoli pv. phaseoli and Xanthomonas citri pv. fuscans is one of the major threats to common bean crops (Phaseolus vulgaris L.). Resistance to CBB is particularly complex as 26 quantitative resistance loci to CBB have been described so far. To date, transcriptomic studies after CBB infection have been very scarce and the molecular mechanisms underlying susceptibility or resistance are largely unknown. Results: We sequenced and annotated the genomes of two common bean genotypes being either resistant (BAT93) or susceptible (JaloEEP558) to CBB. Reciprocal BLASTp analysis led to a list of 20,787 homologs between these genotypes and the common bean reference genome (G19833), which provides a solid dataset for further comparative analyses. RNA-Seq after inoculation with X. phaseoli pv. phaseoli showed that the susceptible genotype initiated a more intense and diverse biological response than the resistant genotype. Resistance was linked to upregulation of the salicylic acid pathway and downregulation of photosynthesis and sugar metabolism, while susceptibility was linked to downregulation of resistance genes and upregulation of the ethylene pathway and of genes involved in cell wall modification. Conclusions: This study helps better understanding the mechanisms occurring during the early colonization phase of common bean by Xanthomonas and unveils new actors potentially important for resistance and susceptibility to CBB. We discuss the potential link between the pathways induced during bean colonization and genes induced by transcription activator-like effectors (TALEs), as illustrated in other Xanthomonas pathovars.
Project description:Functional studies of the genes associated with development and reproduction during different life stages are limited in Zeugodacus cucurbitae. There have yet to be comprehensive transcriptomic resources for genetic and functional genomic studies to identify the molecular mechanisms related to its development and reproduction.
Project description:Dry bean (Phaseolus vulgaris L.) seeds are a rich source of dietary zinc, especially for people consuming plant-based diets. Within P. vulgaris there is at least two-fold variation in seed Zn concentration. Genetic studies have revealed seed Zn differences to be controlled by a single gene in two closely related navy bean genotypes, Albion and Voyager. In this study, these two genotypes were grown under controlled fertilization conditions and the Zn concentration of various plant parts were determined. The two genotypes had similar levels of Zn in their leaves and pods but Voyager had 52% more Zn in its seeds than Albion. RNA was sequence from developing pods of both genotypes. Transcriptome analysis of these genotypes identified 27,198 genes in the developing bean pods, representing 86% of the genes in the P. vulgaris genome (v 1.0 DOE-JGI and USDA-NIFA). Expression was detected in 18,438 genes. A relatively small number of genes (381) were differentially expressed between Albion and Voyager. Differentially expressed genes included three genes potentially involved in Zn transport, including zinc-regulated transporter, iron regulated transporter like (ZIP), zinc-induced facilitator (ZIF) and heavy metal associated (HMA) family genes. In addition 12,118 SNPs were identified between the two genotypes. Of the gene families related to Zn and/or Fe transport, eleven genes were found to contain SNPs between Albion and Voyager.
Project description:Foxtail millet, domesticated from the wild species green foxtail, provides a rich source of phytonutrients for humans. To evaluate how breeding changed the metabolome of foxtail millet grains, we generated and analyzed datasets encompassing genomes, transcriptomes, metabolomes and anti-inflammatory indices from 398 foxtail millet accessions. We identified hundreds of common variants that influence numerous secondary metabolites, with significant heterogeneity in the natural variation of metabolites and their underlying genetic architectures between different sub-groups of foxtail millet. The combined results from variations in genome, transcriptome and metabolome illustrated how breeding has altered foxtail millet metabolite content. Selection for alleles of genes associated with yellow grains led to altered metabolite profiles, such as carotenoids and endogenous hormones. The importance of PSY1 (phytoene synthase 1) for millet color was validated using CRISPR-Cas9. The in vitro cell inflammation assay showed that 83 metabolites have anti-inflammatory effects. This multi-omics study illustrates how the breeding history of foxtail millet has impacted metabolites. It provides some fundamental resources for understanding how grain quality could be associated with different metabolites, and highlights future perspectives on millet genetic research and metabolome-assisted improvement.
2022-05-09 | ST002168 | MetabolomicsWorkbench
Project description:Increasing genetic gain in climbing bean breeding (IncreBean)
Project description:Rice (Oryza sativa) is one of the world's major rations. The widely planted hybrid rice in Jiangxi Province is seriously affected by Magnaporthe oryzae, which seriously restricts the rice yield in Jiangxi Province. In recent years, studies have found that alternative polyadenylation (APA) is an important post-transcriptional regulation in eukaryotes. The genetic law and function of APA in the occurrence of hybrid rice blast in Jiangxi are not clear. In this study, Wufengyou T025 (WFY) and its parents (male parent Changhui T025(CH), and female parent Wufeng B(WFB)) were used as the research objects. Transcriptome and metabolome sequencing, combined with a variety of bioinformatics analysis methods and modern molecular biology experimental techniques, revealed the APA expression profile during the occurrence of Jiangxi hybrid rice blast. To explore the regulatory mechanism of APA core factors during the occurrence of rice blast. This study not only provides a new understanding of the occurrence of Jiangxi hybrid rice blast, but also provides more abundant resources for molecular breeding.
Project description:Drought stress, especially during the seedling stage, seriously limits the growth and development of maize. Understanding the response of maize to drought is the first step in the breeding of tolerant genotypes. Recent advances in deep-sequencing and proteomic techniques, such as isobaric tags for relative and absolute quantitation (iTRAQ), can provide large-scale comparisons and reliable quantitative measurements. Despite previous studies on drought resistance mechanisms by which maize cope with water deficient, the link between physiological and molecular variations are largely unknown. Therefore, understanding the drought tolerance mechanisms of different maize varieties is essential for genetic manipulation and/or cross breeding in maize. Towards this goal, we used a comparative physiological and proteomics analysis approach to monitor the changes of two different drought-resistant maize varieties.
Project description:Common bean (Phaseolus vulgaris) and soybean (Glycine max) both belong to the Phaseoleae tribe and share significant coding sequence homology. To evaluate the utility of the soybean GeneChip for transcript profiling of common bean, we hybridized cRNAs purified from nodule, leaf, and root of common bean and soybean in triplicate to the soybean GeneChip. Initial data analysis showed a decreased sensitivity and specificity in common bean cross-species hybridization (CSH) GeneChip data compared to that of soybean. We employed a method that masked putative probes targeting inter-species variable (ISV) regions between common bean and soybean. A masking signal intensity threshold was selected that optimized both sensitivity and specificity. After masking for ISV regions, the number of differentially-expressed genes identified in common bean was increased by about 2.8-fold reflecting increased sensitivity. Quantitative RT-PCR analysis of a total of 20 randomly selected genes and purine-ureides pathway genes demonstrated an increased specificity after masking for ISV regions. We also evaluated masked probe frequency per probe set to gain insight into the sequence divergence pattern between common bean and soybean. The results from this study suggested that transcript profiling in common bean can be done using the soybean GeneChip. However, a significant decrease in sensitivity and specificity can be expected. Problems associated with CSH GeneChip data can be mitigated by masking probes targeting ISV regions. In addition to transcript profiling CSH of the GeneChip in combination with masking probes in the ISV regions can be used for comparative ecological and/or evolutionary genomics studies.
Project description:Shrub willow (Salix spp.), a short rotation woody biomass crop, has superior properties as a perennial energy crop for the Northeast and Midwest US. However, the insect pest potato leafhopper Empoasca fabae (Harris) (PLH) can cause serious damage and reduce yield of susceptible genotypes. Currently, the willow cultivars in use display varying levels of susceptibility under PLH infestation. However, genes and markers for resistance to PLH are not yet available for marker-assisted selection in breeding. In this study, transcriptome differences between a resistant genotype 94006 (S. purpurea) and a susceptible cultivar ‘Jorr’ (S. viminalis), and their hybrid progeny were determined. Over 600 million RNA-Seq reads were generated and mapped to the Salix purpurea reference transcriptome. Gene expression analyses revealed the unique defense mechanism in resistant genotype 94006 that involves PLH-induced secondary cell wall modification. In the susceptible genotypes, genes involved in programed cell death were highly expressed, explaining the necrosis symptoms after potato leafhopper feeding. Overall, the discovery of resistance genes and defense mechanisms provides new resources for shrub willow breeding and research in the future.
Project description:The Malayan pangolin (Manis javanica), an unusual mammal that is a scale-covered, toothless specialist myrmecophage, is maintained primarily through captive breeding in China. Maintaining this species in captivity is a significant challenge partly because little is known about its behavior and reproduction. The molecular mechanisms of its digestive system play a key role in the feeding and dietary husbandry of pangolins in captivity. Here, we performed the first large-scale sequencing of M. javanica transcriptomes from three digestive organs—the salivary glands, liver, and small intestine—by using Illumina HiSeq technology- to provides useful genetic resources for future functional work that may be relevant for the maintenance of captive pangolins.