Localization of a defensive volatile 4-hydroxy-4-methylpentan-2-one in the capitate glandular trichomes of Oenothera glazioviana

Glandular trichomes of plants produce a wide variety of secondary metabolites which are considered as major defensive chemicals. The capitate glandular trichomes of Oenothera glazioviana(Onagraceae) were collected with laser microdissection and analyzed by gas chromatography-mass spectrometry. The volatile compound 4-hydroxy-4-methylpentan-2-one(1) was identified. We found that compound 1 displays antimicrobial, insecticidal, and phytotoxic activities. These results suggest that compound 1 might function as a defensive compound in the capitate glandular trichomes of O. glazioviana against pathogens, insect herbivores, and presumably competitive plants as well.

Effect of Dachengqi Tang(大承气汤)Granule on Proliferation ofIntestinal Epithelial Cells in Rats with ExperimentalIntestinal Obstruction

Objective: To study the effects of Dachengqi Tang (DCQT) granule on the proliferation of the intestinal epithelial cells in rats with experimental intestinal obstruction. Methods: Experimental intestinal obstruction models were established in rats and autoradiography with 3 H-TdR was used to determine 3H-TdR labeling counts of intestinal epithelial cells in rats. Results: DCQT granule had no effects on 3H-TdR labeling counts of intestinal epithelial cells in normal rats. DCQT granule obviously increases the rate of renovation in intestinal epithelial cells of the intestinal obstruction rats. Conclusion: DCQT granule could reinforce the intestinal mucosa's defensive function by means of increasing the proliferation of intestinal epithelial cells.

Geographic patterns of plant-herbivore interactions are driven by soil fertility

Aims Geographic patterns of the intensity of plant herbivory in relation to climate factors have garnered little general support and appear to be species specific.However,plant-herbivore interactions are also driven by resource availability,such as soil nutrient content,and it remains unclear whether broad-scale variation in soil factors is reflected in herbivore consumption rates across species’ranges.Additionally,we know little of how intraspecific variation in tissue quality associates with edaphic and climatic factors,and how this variation controls herbivore consumption.The resource availability hypothesis(RAH)predicts that plant individuals growing in low-resource environments will have lower leaf nutritional quality and more constitutive defenses,which will result in lower rates of leaf consumption.Methods We collected leaves from the old-field dominant species,Solidago altissima L.,from 20 sites across 10 degrees of latitude in the Eastern USA to determine the percentage leaf area consumed by insect foli-vores.We obtained soil and climate data for each site,as well as plant functional and defensive traits,including specific leaf area(SLA),leaf carbon:nitrogen(C:N),and trichome density.Important Findings Although we found no significant latitudinal trend of leaf consump-tion rate,there was strong evidence that leaf herbivory decreased with leaf C:N and trichome density,which themselves decreased with soil N,supporting our hypothesis that the RAH applies for intraspecific variation across spatial gradients.Additionally,high precipitation seasonality and soil nitrogen predicted decreased her-bivory.The results suggest that spatial variation in herbivory can be driven by factors other than herbivore communities and climatic gradients,and that bottom-up processes,where plant traits and soil fertility control leaf consumption,must be incorporated into spatial predictions of herbivory.