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Ajuga multiflora Bunge is a perennial ornamental herb and has been used for the treatment of fever in Korean folk medicine. In the course of searching for protective agents associated with the potential of A. multiflora against dexamethsone (DEX)-induced muscle atrophy, a new phytoecdysteroid, 29-hydroxyprecyasterone (1), together with four known compounds (2–5), were isolated from A. multiflora. The structures of the compounds were determined by spectroscopic analyses, including 1D-, 2D-NMR and HR-MS interpretation. To elucidate the effects of obtained compounds on DEX-induced muscle atrophy, the myotubes diameter, myosin heavy chain (MyHC) positive area, and fusion index were evaluated by immunofluorescence staining. Overall, each compound treatment effectively prevented the atrophic myotubes through an increase of MyHC-positive myotubes and the number of nuclei. Particularly, the measurement of myotube diameter showed that compounds 1 and 5 treatment significantly alleviated the myotube thickness. [ABSTRACT FROM AUTHOR]

Bacteria emit volatile compounds that modulate plant growth. Previous studies reported the impacts of bacterial volatile compounds on plant growth; however, the results varied depending on bacterial nutrient availability. We investigated whether the effects of plant growth–inhibiting volatiles (PGIVs) and plant growth–promoting volatiles (PGPVs) depended on the perceived dose by evaluating the growth of Arabidopsis thaliana seedlings placed at 7, 14, and 21 cm away from Bacillus amyloliquefaciens GB03 colonies growing in rich medium. A large bacterial colony (500 μl inoculum) inhibited plant growth at 7 cm and promoted growth at 21 cm, whereas a small bacterial colony (100 μl inoculum) induced the opposite pattern of response. We identified pyrazine and 2,5-dimethylpyrazine as candidate PGIVs that significantly reduced plant growth at a distance of 7 cm. PGIV effects were validated by exposing plants to synthetic 2,5-dimethylpyrazine and bacteria emitting PGPVs, which showed that PGIVs overwhelm PGPVs to rapidly increase salicylic acid content and related gene expression. This is referred to as the defence-growth trade-off. Our results indicate that high PGIV concentrations suppress plant growth and promote immunity, whereas low PGPV concentrations promote growth. This study provides novel insights into the complex effects of bacterial volatile mixtures and fine-tuning of bacteria-plant interactions. Bacillus amyloliquefaciens GB03 emits volatile pyrazines, which exhibit plant growth inhibitory activity at shorter distances between plants and the volatile source. [ABSTRACT FROM AUTHOR]

Volatile compounds play important roles in rhizosphere biological communications and interactions. The emission of plant and microbial volatiles is a dynamic phenomenon that is affected by several endogenous and exogenous signals. Diffusion of volatiles can be limited by their adsorption, degradation, and dissolution under specific environmental conditions. Therefore, rhizosphere volatiles need to be investigated on a micro and spatiotemporal scale. Plant and microbial volatiles can expand and specialize the rhizobacterial niche not only by improving the root system architecture such that it serves as a nutrient-rich shelter, but also by inhibiting or promoting the growth, chemotaxis, survival, and robustness of neighboring organisms. Root volatiles play an important role in engineering the belowground microbiome by shaping the microbial community structure and recruiting beneficial microbes. Microbial volatiles are appropriate candidates for improving plant growth and health during environmental challenges and climate change. However, some technical and experimental challenges limit the non-destructive monitoring of volatile emissions in the rhizosphere in real-time. In this review, we attempt to clarify the volatile-mediated intra- and inter-kingdom communications in the rhizosphere, and propose improvements in experimental design for future research. Microbial, plant, and microbe-induced plant volatile compounds modulate belowground biological interactions and shape the soil microbial community structure. This volatile-mediated plant–soil feedback promotes plant growth and health. [ABSTRACT FROM AUTHOR]

Upon sensing attack by pathogens and insect herbivores, plants release complex mixtures of volatile compounds. Here, we show that the infection of lima bean (Phaseolus lunatus L.) plants with the non‐host bacterial pathogen Pseudomonas syringae pv. tomato led to the production of microbe‐induced plant volatiles (MIPVs). Surprisingly, the bacterial type III secretion system, which injects effector proteins directly into the plant cytosol to subvert host functions, was found to prime both intra‐ and inter‐specific defense responses in neighbouring wild tobacco (Nicotiana benthamiana) plants. Screening of each of 16 effectors using the Pseudomonas fluorescens effector‐to‐host analyser revealed that an effector, HopP1, was responsible for immune activation in receiver tobacco plants. Further study demonstrated that 1‐octen‐3‐ol, 3‐octanone and 3‐octanol are novel MIPVs emitted by the lima bean plant in a HopP1‐dependent manner. Exposure to synthetic 1‐octen‐3‐ol activated immunity in tobacco plants against a virulent pathogen Pseudomonas syringae pv. tabaci. Our results show for the first time that a bacterial type III effector can trigger the emission of C8 plant volatiles that mediate defense priming via plant–plant interactions. These results provide novel insights into the role of airborne chemicals in bacterial pathogen‐induced inter‐specific plant–plant interactions. Our results demonstrated two significant progresses on microbe‐induced plant volatile (MIPV). First, out of intensive screening to identify bacterial determinant(s) that induce plant volatiles to increase bacterial immunity on neighbouring plant, we newly identified a bacterial type III effector HopP1 from Pseudomonas syringae pv. tomato corresponding to MIPV. Secondly, the bacterial type III effector HopP1 induces the production of C8 volatile organic compounds, 1‐octen‐3‐ol, 3‐octanone and 3‐octanol on lima bean that in turn interspecifically prime plant defense against virulent bacterial pathogen P. syrinage pv. tabaci on neighbouring plant Nicotiana benthamiana. To our best knowledge, this is the first studies that type III secretion system–dependent bacterial effectors induce plant volatiles. [ABSTRACT FROM AUTHOR]

Gastrodia rhizome, a dried and steamed tuber of Gastrodia elata Blume (Orchidaceae), has been traditionally used in Korea, China and Japan for the treatment of neurological and nervous disorders such as headaches, dizziness, vertigo and convulsive illnesses. The ethyl acetate and water extracts of G. elata stimulated plasmin activity. The active ethyl acetate fraction was subjected to centrifugal partition chromatography (CPC) with a two-phase solvent system, composed of n-hexane-ethyl acetate-methanol-water (3:7:4:6, v/v) followed by semi-preparative HPLC purification to separate active compounds and the water fraction was purified by Diaion HP-20 resin and semi-preparative HPLC. In ethyl acetate extract, 4-hydroxybenzyl alcohol (1), 4-hydroxybenzoic acid (2), 4-hydroxybenzaldehyde (3), 4-ethoxymethylphenol (4), 4,4′-oxy bis(methylene)diphenol (5) and 4,4′-methylenediphenol (6) were obtained with high purities. Parishin (7) and parishin B (8) were isolated from water extract. Among isolated compounds, 4-hydroxybenzyl alcohol (1), 4-hydroxybenzaldehyde (3) and 4-ethoxymethylphenol (4) significantly stimulated plasmin activity. Copyright © 2015 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

ABSTRACT Gradient HPLC coupled to Diode Array Detector (DAD), MS/MS and NMR was applied to the rapid structure determination of major compounds of methanol extracts from leaves and roots of Petasites japonicus. The relative antioxidant capacities of the compounds were evaluated by an HPLC system with post-column on-line antioxidant detection based on 2,2′-azinobis-3-ethylbenzothiazoline-6-sulfonic acid radical scavenging. Six compounds were successfully separated on a reverse-phase C18 column and were identified as 5-caffeoylquinic acid (5-CQA), fukinolic acid (FA), 3,5-di- O-caffeoylquinic acid (3,5-DCQA), quercetin-3- O-(6″-acetyl)- β-glucopyranoside (QAG), 4,5-di- O-caffeoylquinic acid (4,5-DCQA) and kaempferol-3- O-(6″-acetyl)- β-glucopyranoside (KAG) by MS/MS and 1H NMR data. Among these compounds, those containing a caffeoyl moiety (5-CQA, FA, 3,5- and 4,5-DCQA) showed relatively strong radical scavenging capacity, with 3,5-DCQA having the greatest radical scavenging capacity in leaf (23.09% of total antioxidant capacity) and root (26.47%) extracts. The relative radical scavenging portion of QAG was only 3.41% in the leaves and KAG did not show any radical scavenging activity. These results demonstrate that the hyphenated HPLC techniques can be successfully applied to rapidly identify structures and evaluate antioxidant activities without prior purification of compounds from plant tissues of P. japonicus. Copyright © 2011 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]