Metabolomics responses of Bambusa pervariabilis × Dendrocalamopsis grandis varieties to Biotic (pathogenic fungus) stress

Development and Comparison of Seminested PCR, qPCR, and LAMP for the Rapid Detection of Arthrinium phaeospermum, the Causal Agent of Bamboo Blight

Bambusa pervariabilis × Dendrocalamopsis grandis blight is a newly discovered disease in bamboos that has caused substantial economic loss to the affected areas. With the purpose of carrying out rapid detection of Bambusa pervariabilis × Dendrocalamopsis grandis blight caused by Arthrinium phaeospermum during the incubation period, three sets of detection assays were established: seminested PCR, real-time quantitative PCR, and LAMP. The specificity, sensitivity, and effectiveness of these assays were also detected. The results showed that the three assays were able to specifically amplify the target bands from five strains of Arthriniumphaeospermum from different sources, but none of the other 18 strains were able to obtain the specific bands. The sensitivity of the established seminested PCR, LAMP, and real-time quantitative PCR assays were 100, 10, and 1 pg/μL, respectively. The presence of A. phaeospermum could be detected in the early stage of disease using the total DNA of infected hybrid bamboo tissue as a template. The three systems established in this study are of great significance for the early diagnosis and rapid detection of hybrid bamboo blight.

Profiling alkaloids in Aconitum pendulum N. Busch collected from different elevations of Qinghai province using widely targeted metabolomics

Aconitum pendulum N. Busch (Ranunculaceae) is rich in alkaloids with anti-inflammatory and analgesic activities. Many studies have focused on the identification or quantification of alkaloid components using low-throughput tests. However, the metabolic differences of plants from environmentally distinct regions remain unclear. The present study profiled alkaloid chemical compounds in the rhizomes of A. pendulum from different regions. A total of 80 chemical compounds were identified using a widely targeted ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) approach. Principal component, hierarchical clustering, and orthogonal partial least squares-discriminant analyses of the chemical compounds indicated that the plants from 6 regions clearly separated into distinct groups. A total of 19 compounds contributed the most to the metabolite differences between collection areas and were identified as potential metabolic markers. The anti-inflammatory activities of the A. pendulum extracts were also evaluated and the potential environmental effects on the regulation of metabolite composition and bioactivity were explored. These results improve our understanding of the variation in chemical composition of plants from different regions and will serve as a reference for evaluating the medicinal value of A. pendulum in different environments.

Untargeted LC-MS-based metabolomics revealed specific metabolic changes in cotyledons and roots of Ricinus communis during early seedling establishment under salt stress

Early seedling development is one of the most crucial period of the plant's life cycle, which is highly susceptible to adverse environmental conditions, especially those impose by salt stress. Castor plant (Ricinus communis) is a famous non-edible oilseed and salt-resistant crop worldwide. However, the specific metabolic responses in the cotyledons and roots of this species during seedling establishment under salt stress are still not clearly understood. In the present study, 16 d castor seedlings were treated with 150 mM NaCl for 6 d, and the metabolite profiling of cotyledons and roots was conducted using liquid chromatography (LC) combined with electrospray ionization time-of-flight mass spectrometry (ESI-TOF-MS). The Principal Component Analysis (PCA) results showed that the metabolites were great differed in cotyledons and roots under salt stress. There were 38 differential metabolites, mainly including fatty acid, nucleic acid and organic acids in the cotyledons, but only 19 differential metabolites, mainly including fatty acid and organic acids in the roots under such condition. Furthermore, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis revealed that flavone and flavonol biosynthesis, pantothenate and CoA biosynthesis, citrate cycle and carotenoid biosynthesis were the common metabolic pathways in response to salt stress in the two organs. Salt stress caused metabolite process alteration mainly on carbon and nitrogen metabolisms, and the carbon allocation from root to cotyledon was increased. Additionally, changes of amino acids and nucleic acids profiles were only found in the cotyledons, and the roots could enhance the activity of antioxidant enzyme systems to scavenge ROS under salinity. In conclusion, the present research provides an improved understanding on specific physiological changes in the cotyledons in castor early seedlings, and explores their interaction under salt stress.

Investigation of Differentially Expressed Proteins Induced by Alteration of Natural Se Uptake with Ultrahigh-Performance Liquid Chromatography Quadrupole Orbitrap Uncovers the Potential Nutritional Value in Se-Enriched Green Tea

Se-enriched green tea, with an increasing consumption, is the shoot of tea plants grown naturally in a seleniferous region. A label-free proteomic strategy based on ultrahigh-performance liquid chromatography quadrupole Orbitrap was applied to characterize and distinguish the difference between the Se-enriched and normal green tea with a total of 283 proteins identified and 264 proteins quantified, in which 96 proteins were observed different. The expressions of 10 proteins were upregulated and 40 proteins were downregulated (p < 0.05) in Se-enriched samples. Gene ontology, Kyoto Encyclopedia of Genes and Genomes pathway, and protein-protein interaction (PPI) network analysis results indicated that these differentially expressed proteins significantly interacted and were involved in secondary metabolites and inflammatory response biological processes. Furthermore, the expression of methyl-jasmonate- and ethylene-related genes changed significantly in Se-enriched green tea, and catalase proteins were employed as the center of the pathway that changed significantly in the PPI network. These results associating with the current knowledge of selenium in soil-plant cycling revealed that organic selenium was synthesized in green tea, which provided novel information on Se assimilation in Camellia sinensis and improved the understanding of Se-enriched green tea as a possible ideal selenium supplement in daily life.

Differential Proteome Analysis of Hybrid Bamboo (Bambusa pervariabilis × Dendrocalamopsis grandis) Under Fungal Stress (Arthrinium phaeospermum)

In this study, TMT (tandem mass tag)-labeled quantitative protein technology combined with LC–MS/MS (liquid chromatography-mass spectrometry/mass spectrometry) was used to isolate and identify the proteins of the hybrid bamboo (Bambusa pervariabilis × Dendrocalamopsis grandis) and the bamboo inoculated with the pathogenic fungi Arthrinium phaeospermum. A total of 3320 unique peptide fragments were identified after inoculation with either A. phaeospermum or sterile water, and 1791 proteins were quantified. A total of 102 differentially expressed proteins were obtained, of which 66 differential proteins were upregulated and 36 downregulated in the treatment group. Annotation and enrichment analysis of these peptides and proteins using the GO (Gene Ontology) and KEGG (Kyoto Encyclopedia of Genes and Genomes) databases with bioinformatics software showed that the differentially expressed protein functional annotation items were mainly concentrated on biological processes and cell components. The LC–PRM/MS (liquid chromatography-parallel reaction monitoring/mass spectrometry) quantitative analysis technique was used to quantitatively analyze 11 differential candidate proteins obtained by TMT combined with LC–MS/MS. The up–down trend of 10 differential proteins in the PRM results was consistent with that of the TMT quantitative analysis. The coincidence rate of the two results was 91%, which confirmed the reliability of the proteomic results. Therefore, the differentially expressed proteins and signaling pathways discovered here may be the further concern for the bamboo-pathogen interaction studies.