the two-spotted spider mite, tetranychus urticae koch (acari: tetranychidae) is one of the most important agricultural pests of the world. it causes direct and indirect damage on plants which decreases in photosynthesis and crop yield. the effect of sublethal concentrations of artemisia annua l. (asteraceae) and rosmarinus officinalis l. (lamiaceae) essential oils were assessed on development a...

Different but partially overlapping hypotheses have been developed to predict the allocation of phenolics in elevated atmospheric CO(2). The carbon-nutrient balance hypothesis predicts increased allocation to phenolics due to reduced relative availability of nitrogen. The growth-differentiation balance hypothesis states that allocation will depend on source and sink strength, while the protein ...

[This corrects the article on p. 626 in vol. 5, PMID: 25505453.].

The emergence of terpene cyclization was critical to the evolutionary expansion of chemical diversity yet remains unexplored. Here we report the first discovery of an epistatic network of residues that controls the onset of terpene cyclization in Artemisia annua. We begin with amorpha-4,11-diene synthase (ADS) and (E)-β-farnesene synthase (BFS), a pair of terpene synthases that produce cyclic o...

The rate o f photosynthesis in intact leaves o f a triazine-resistant biotype o f Amaranthus retroflexus was about 15% lower than that o f a triazine-susceptible biotype. Differences in photosyn­ thesis between resistant and susceptible biotypes o f Polygonum lapathifolium, Poa annua and Solanum nigrum were not significant, and absent in Chenopodium album and Stellaria media. The results are br...

4-Hydroxy-3-methylbut-2-enyl diphosphate reductase (HDR) catalyzes the last step of the 2-C-methyl-D-erythritol 4- phosphate (MEP) pathway to synthesize isopentenyl pyrophosphate (IPP) and dimethylallyl diphosphate (DMAPP). To date, little is known regarding effects of an increase or a decrease of a HDR expression on terpenoid and other metabolite profiles in plants. In our study, an Artemisia ...

At some point during biosynthesis of the antimalarial artemisinin in glandular trichomes of Artemisia annua, the Delta11(13) double bond originating in amorpha-4,11-diene is reduced. This is thought to occur in artemisinic aldehyde, but other intermediates have been suggested. In an effort to understand double bond reduction in artemisinin biosynthesis, extracts of A. annua flower buds were inv...