We identify a cytochrome P450 gene (CYP6AE14) from cotton bollworm (Helicoverpa armigera), which permits this herbivore to tolerate otherwise inhibitory concentrations of the cotton metabolite, gossypol. CYP6AE14 is highly expressed in the midgut and its expression correlates with larval growth when gossypol is included in the diet. When larvae are fed plant material expressing double-stranded RNA (dsRNA) specific to CYP6AE14, levels of this transcript in the midgut decrease and larval growth is retarded. Both effects are more dramatic in the presence of gossypol. As a glutathione-S-transferase gene (GST1) is silenced in GST1 dsRNA-expressing plants, feeding insects plant material expressing dsRNA may be a general strategy to trigger RNA interference and could find applications in entomological research and field control of insect pests.

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RNA interference (RNAi) plays an important role in regulating gene expression in eukaryotes. Previously, we generated Arabidopsis and tobacco plants expressing double-stranded RNA (dsRNA) targeting a cotton bollworm (Helicoverpa armigera) P450 gene, CYP6AE14. Bollworms fed on transgenic dsCYP6AE14 plants showed suppressed CYP6AE14 expression and reduced growth on gossypol-containing diet (Mao et al., in Nat Biotechnol 25: 1307–1313, 2007). Here we report generation and analysis of dsRNA-expressing cotton (Gossypium hirsutum) plants. Bollworm larvae reared on T2 plants of the ds6-3 line exhibited drastically retarded growth, and the transgenic plants were less damaged by bollworms than the control. Quantitative reverse-transcription polymerase chain reaction (RT-PCR) showed that the CYP6AE14 expression level was reduced in the larvae as early as 4 h after feeding on the transgenic plants; accordingly, the CYP6AE14 protein level dropped. These results demonstrated that transgenic cotton plants expressing dsCYP6AE14 acquired enhanced resistance to cotton bollworms, and that RNAi technology can be used for engineering insect-proof cotton cultivar.Electronic supplementary materialThe online version of this article (doi:10.1007/s11248-010-9450-1) contains supplementary material, which is available to authorized users.

Objective. To examine the safety and efficacy of an extract of Tripterygium wilfordii Hook F (TWHF) in the treatment of patients with rheumatoid arthritis (RA).Methods. An ethanol/ethyl acetate extract from the roots of TWHF was prepared and used in a prospective, double-blind, placebo-controlled study in patients with longstanding RA in whom conventional therapy had failed. Patients were randomly assigned to receive either placebo or low-dose ( Conclusion. The ethanol/ethyl acetate extract of TWHF shows therapeutic benefit in patients with treatment-refractory RA. At therapeutic dosages, the TWHF extract was well tolerated by most patients in this study.

Background Extracts of the medicinal plant Tripterygium wilfordii Hook F (TwHF) have been used in China for centuries to treat a spectrum of inflammatory diseases. Objective To compare the benefits and side effects of TwHF extract with those of sulfasalazine for the treatment of active rheumatoid arthritis. Design Randomized, controlled trial. A computer-generated code with random, permuted blocks was used to assign treatment. Setting 2 U.S. academic centers (National Institutes of Health, Bethesda, Maryland, and University of Texas, Dallas, Texas) and 9 rheumatology subspecialty clinics (in Dallas and Austin, Texas; Tampa and Fort Lauderdale, Florida; Arlington, Virginia; Duncanville, Pennsylvania; Wheaton and Greenbelt, Maryland; and Lansing, Michigan). Patients 121 patients with active rheumatoid arthritis and 6 or more painful and swollen joints. Intervention TwHF extract, 60 mg 3 times daily, or sulfasalazine, 1 g twice daily. Patients could continue stable doses of oral prednisone or nonsteroidal anti-inflammatory drugs but had to stop taking disease-modifying antirheumatic drugs at least 28 days before randomization. Measurements The primary outcome was the rate of achievement of 20% improvement in the American College of Rheumatology criteria (ACR 20) at 24 weeks. Secondary end points were safety; radiographic scores of joint damage; and serum levels of interleukin-6, cholesterol, cortisol, and adrenocorticotropic hormone. Results Outcome data were available for only 62 patients at 24 weeks. In a mixed-model analysis that imputed data for patients who dropped out, 65.0% (95% CI, 51.6% to 76.9%) of the TwHF group and 32.8% (CI, 21.3% to 46.0%) of the sulfasalazine group met the ACR 20 response criteria (P = 0.001). Patients receiving TwHF also had significantly higher response rates for ACR 50 and ACR 70 in mixed-model analyses. Analyses of only completers showed similar significant differences between the treatment groups. Significant improvement was demonstrated in all individual components of the ACR response, including the Health Assessment Questionnaire disability score. Interleukin-6 levels rapidly and significantly decreased in the TwHF group. Although not statistically significant, radiographic progression was lower in the TwHF group. The frequency of adverse events was similar in both groups. Limitations Only 62% and 41% of patients continued receiving TwHF extract and sulfasalazine, respectively, during the 24 weeks of the study. Long-term outcome data were not collected on participants who discontinued treatment. Conclusion In patients who continued treatment for 24 weeks and could also use stable oral prednisone and nonsteroidal anti-inflammatory drugs, attainment of the ACR 20 response criteria was significantly greater with TwHF extract than with sulfasalazine. Primary Funding Source National Institute of Arthritis and Musculoskeletal and Skin Diseases.

Cotton plants accumulate phytotoxins, including gossypol and related sesquiterpene aldehydes, to resist insect herbivores and pathogens. To counteract these defensive plant secondary metabolites, cotton bollworms (Helicoverpa armigera) elevate their production of detoxification enzymes, including cytochrome P450 monooxygenases (P450s). Besides their tolerance to phytotoxin, cotton bollworms have quickly developed resistance to deltamethrin, a widely used pyrethroid insecticide in cotton field. However, the relationship between host plant secondary metabolites and bollworm insecticide resistance is poorly understood. Here, we show that exogenously expressed CYP6AE14, a gossypol-inducible P450 of cotton bollworm, has epoxidation activity towards aldrin, an organochlorine insecticide, indicating that gossypol-induced P450s participate in insecticide metabolism. Gossypol-ingested cotton bollworm larvae showed higher midgut P450 enzyme activities and exhibited enhanced tolerance to deltamethrin. The midgut transcripts of bollworm larvae administrated with different phytochemicals and deltamethrin were then compared by microarray analysis, which showed that gossypol and deltamethrin induced the most similar P450 expression profiles. Gossypol-induced P450s exhibited high divergence and at least five of them (CYP321A1, CYP9A12, CYP9A14, CYP6AE11 and CYP6B7) contributed to cotton bollworm tolerance to deltamethrin. Knocking down one of them, CYP9A14, by plant-mediated RNA interference (RNAi) rendered the larvae more sensitive to the insecticide. These data demonstrate that generalist insects can take advantage of secondary metabolites from their major host plants to elaborate defence systems against other toxic chemicals, and impairing this defence pathway by RNAi holds a potential for reducing the required dosages of agrochemicals in pest control.

Tripterygium wilfordii Hook F (TWH) is a vine‐like plant that grows in a wide area of south China. An alcohol extract of this plant known as T2 has been suggested to be effective in the treatment of rheumatoid arthritis (RA). To examine the mechanism by which this herbal remedy might be effective in RA, the capacity of T2 to alter human immune responsiveness in vitro was investigated. Human peripheral blood mononuclear cells were obtained from normal adults and separated into purified populations of monocytes, T cells, and B cells. T2 at 0.1–1 μg/ml inhibited antigen‐ and mitogen‐stimulated proliferation of T cells and B cells, interleukin‐2 (IL‐2) production by T cells, and immunoglobulin production by B cells. T2 did not affect IL‐2 receptor expression by T cells, IL‐1 production by monocytes, or the capacity of monocytes to present antigen. Inhibition could not be accounted for by nonspecific toxicity. These results support the conclusion that T2 exerts a powerful suppressive effect on human immune responses. This action might account for its therapeutic effectiveness in RA.

BackgroundInterspecific hybridization and whole genome duplication are driving forces of genomic and organism diversification. But the effect of interspecific hybridization and whole genome duplication on the non-coding portion of the genome in particular remains largely unknown. In this study, we examine the profile of long non-coding RNAs (lncRNAs), comparing them with that of coding genes in allotetraploid cotton (Gossypium hirsutum), its putative diploid ancestors (G. arboreum; G. raimondii), and an F1 hybrid (G. arboreum × G. raimondii, AD).ResultsWe find that most lncRNAs (80%) that were allelic expressed in the allotetraploid genome. Moreover, the genome shock of hybridization reprograms the non-coding transcriptome in the F1 hybrid. Interestingly, the activated lncRNAs are predominantly transcribed from demethylated TE regions, especially from long interspersed nuclear elements (LINEs). The DNA methylation dynamics in the interspecies hybridization are predominantly associated with the drastic expression variation of lncRNAs. Similar trends of lncRNA bursting are also observed in the progress of polyploidization. Additionally, we find that a representative novel lncRNA XLOC_409583 activated after polyploidization from a LINE in the A subgenome of allotetraploid cotton was involved in control of cotton seedling height.ConclusionOur results reveal that the processes of hybridization and polyploidization enable the neofunctionalization of lncRNA transcripts, acting as important sources of increased plasticity for plants.Electronic supplementary materialThe online version of this article (10.1186/s13059-018-1574-2) contains supplementary material, which is available to authorized users.