Identification and quality evaluation of Lushan Yunwu tea from different geographical origins based on metabolomics.

The relationship between the chemical composition and quality of Lushan Yunwu tea (LYT) from different geographical origins is not clear. Sensory evaluation, metabolomics analyses combined with chemometrics were conducted on LYT from 8 different geographical origins, and altitude was identified as the main factor responsible for the differences among LYT. A total of 32 non-volatile and 27 volatile compounds were identified as marker metabolites to distinguish the origins of high altitudes from those of low altitudes.

Identification and Characterization of Polyamine Metabolism in Citrus in Response to ' Liberibacter asiaticus' Infection.

Citrus Huanglongbing, one of the most devastating citrus diseases, is caused by ' Liberibacter asiaticus' (Las). Polyamines are aliphatic nitrogen-containing compounds that play important roles in disease resistance and are synthesized primarily by two pathways: an arginine decarboxylation pathway and an ornithine decarboxylation pathway. However, it is unclear whether polyamines play a role in the tolerance of citrus to infection by Las and, if so, whether one or both of the core polyamine metabolic pathways are important.

Flavonoid profile of Anoectochilus roxburghii (Wall.) Lindl. Under short-term heat stress revealed by integrated metabolome, transcriptome, and biochemical analyses.

Global warming severely threatens plant growth, and could lead to yield reduction. Although findings suggest that flavonoids play important roles in biological process in plants, their response to heat stress in Anoectochilus roxburghii (Wall.) Lindl.

Metabolic Profiling of L. Triggered by Chilling Stress Using Ultraperformance Liquid Chromatography Coupled with Quadrupole/Time-of-Flight Mass Spectrometry (UPLC-QTOF-MS) with Transcriptome Analysis.

Low temperature, a major abiotic stress, often causes molecular changes in crops, which leads to metabolic disturbances and probably affects crop yield. In this study, chilling stress induced distinct metabolic profiles associated with transcriptome regulation, exhibiting great metabolic differences between Qiutianxiaoting () and 93-11 (). In total, 41 and 58 differential metabolites were screened and identified in Qiutianxiaoting and 93-11, respectively.

Early detection of Huanglongbing with EESI-MS indicates a role of phenylpropanoid pathway in citrus.

Huanglongbing (HLB), a devastating disease for citrus worldwide, is caused by Candidatus Liberibacter asiaticus (CLas). In this study, we employed a novel extractive electrospray ionization-mass spectrometry (EESI-MS) method to analyze the metabolites in leaves of uninfected and HLB-infected Newhall navel orange. The results showed that uninfected and HLB-infected leaves could be readily distinguished based on EESI-MS combined by multivariable analysis.

Differential Antioxidant Compounds and Activities in Seedlings of Two Rice Cultivars Under Chilling Treatment.

Variations in antioxidant compounds were examined in seedlings of two rice cultivars (Qiutianxiaoting and 93-11) exposed to low temperature (4°C) for 0, 12, 36, and 48 h. Antioxidant activity was identified by 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) assays. The concentrations of total phenols, flavonoids, chlorophyll, and anthocyanins (ACNs) were determined by spectrophotometry.

Metabolic response of Citrus limon to Asian citrus psyllid infestation revealed by EESI-MS and HPLC.

Asian citrus psyllid (ACP) causes direct and indirect damage to the citrus industry. Extractive electrospray ionization mass spectrometry (EESI-MS) and high performance liquid chromatography (HPLC) were used to detect the metabolites of C. limon leaves at 0, 12, 24, and 72 h after ACP treatment.

Direct identification and metabolomic analysis of Huanglongbing associated with Candidatus Liberibacter spp. in navel orange by MALDI-TOF-MS.

Citrus Huanglongbing (HLB) is one of the most destructive citrus diseases worldwide, and is associated with the phloem-limited plant pathogenic bacteria Candidatus Liberibacter species. However, there is a latency period during which newly infected trees do not show symptoms, creating challenges for the early detection of HLB. In order to establish a method for rapid detection and to assess the metabolite differences between healthy and HLB-affected Newhall navel oranges, we used matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) to study asymptomatic and symptomatic leaf extracts compared with healthy leaves.

Chemical Composition and Antioxidant Activity of Essential Oil of Chinese Propolis.

The chemical composition and in vitro antioxidant activity of the essential oil of propolis (EOP) collected from 25 locations in China was investigated. Steam-distillation extraction was used to extract the EOP, and chemical composition was identified by GC/MS. The antioxidant activities of EOP were also measured.

In Situ Study of Metabolic Response of Leaves to Salt Stress by Neutral Desorption-Extractive Electrospray Ionization Mass Spectrometry.

Salt stress is one of the most common factors limiting plant cultivation. In this study, metabolic responses to salt stress in () leaves were analyzed in situ by neutral desorption-extractive electrospray ionization mass spectrometry (ND-EESI-MS) without any sample pretreatment. Metabolic changes of leaves were observed in response to salt stress conditions, including the levels of serine, glutamic acid, arginine, cinnamic acid, ferulic acid, caffeic acid, protocatechuic acid, epicatechin, morin, myricetin, apigravin, and β-cotonefuran.

Dynamic changes of phenolic compounds during artificial aging of soybean seeds identified by high-performance liquid chromatography coupled with transcript analysis.

Phenolic compounds are important bioactive substances in plants, but study of their alteration during soybean seed aging is still limited. In this study, we conducted artificial aging on soybean seeds, detected the dynamic changes of phenolic compound concentrations using high-performance liquid chromatography, and analyzed the gene expression of key enzymes of phenolic metabolism. A detailed method for detection of 19 phenolic compounds during artificial aging of soybean seeds was constructed, and all of these phenols significantly changed in concentration.

TaMCA1, a regulator of cell death, is important for the interaction between wheat and Puccinia striiformis.

Metacaspase orthologs are conserved in fungi, protozoa and plants, however, their roles in plant disease resistance are largely unknown. In this study, we identified a Triticum aestivum metacaspase gene, TaMCA1, with three copies located on chromosomes 1A, 1B and 1D. The TaMCA1 protein contained typical structural features of type I metacaspases domains, including an N-terminal pro-domain.

Transcriptome Analysis Provides Insights into the Mechanisms Underlying Wheat Plant Resistance to Stripe Rust at the Adult Plant Stage.

Stripe rust (or yellow rust), which is caused by Puccinia striiformis f. sp. tritici (Pst), is one of the most devastating wheat diseases worldwide.