Volatile 1-octen-3-ol increases patulin production by Penicillium expansum on a patulin-suppressing medium.

1-Octen-3-ol is one of the most abundant volatile compounds associated with fungi and functions as a germination and growth inhibitor in several species. By investigating its effect on the biosynthesis of patulin, a mycotoxin made by Penicillium expansum, it was found that a sub-inhibitory level of volatile 1-octen-3-ol increased accumulation of patulin on a medium that normally suppresses the mycotoxin. Transcriptomic sequencing and comparisons of control and treated P. expansum grown on potato dextrose agar (PDA; patulin permissive) or secondary medium agar (SMA; patulin suppressive) revealed that the expression of gox2, a gene encoding a glucose oxidase, was significantly affected, decreasing 10-fold on PDA and increasing 85-fold on SMA. Thirty other genes, mostly involved in transmembrane transport, oxidation-reduction, and carbohydrate metabolism were also differently expressed on the two media. Transcription factors previously found to be involved in regulation of patulin biosynthesis were not significantly affected despite 1-octen-3-ol increasing patulin production on SMA. Further study is needed to determine the relationship between the upregulation of patulin biosynthesis genes and gox2 on SMA, and to identify the molecular mechanism by which 1-octen-3-ol induced this effect.

Transcriptomic analysis in Anemone flaccida rhizomes reveals ancillary pathway for triterpene saponins biosynthesis and differential responsiveness to phytohormones.

Anemone flaccida Fr. Schmidt is a perennial medicinal herb that contains pentacyclic triterpenoid saponins as the major bioactive constituents. In China, the rhizomes are used as treatments for a variety of ailments including arthritis. However, yields of the saponins are low, and little is known about the plant's genetic background or phytohormonal responsiveness. Using one-quarter of the 454 pyrosequencing information from the Roche GS FLX Titanium platform, we performed a transcriptomic analysis to identify 157 genes putatively encoding 26 enzymes involved in the synthesis of the bioactive compounds. It was revealed that there are two biosynthetic pathways of triterpene saponins in A. flaccida. One pathway depends on ß-amyrin synthase and is similar to that found in other plants. The second, subsidiary ("backburner") pathway is catalyzed by camelliol C synthase and yields ß-amyrin as minor byproduct. Both pathways used cytochrome P450-dependent monooxygenases (CYPs) and family 1 uridine diphosphate glycosyltransferases (UGTs) to modify the triterpenoid backbone. The expression of CYPs and UGTs were quite different in roots treated with the phytohormones methyl jasmonate, salicylic acid and indole-3-acetic acid. This study provides the first large-scale transcriptional dataset for the biosynthetic pathways of triterpene saponins and their phytohormonal responsiveness in the genus Anemone.

Proteomics of methyl jasmonate induced defense response in maize leaves against Asian corn borer.

BACKGROUND: Jasmonic acid (JA) and methyl jasmonate (MeJA) regulate plant development, resistance to stress, and insect attack by inducing specific gene expression. However, little is known about the mechanism of plant defense against herbivore attack at a protein level. Using a high-resolution 2-D gel, we identified 62 MeJA-responsive proteins and measured protein expression level changes. RESULTS: Among these 62 proteins, 43 proteins levels were increased while 11 proteins were decreased. We also found eight proteins uniquely expressed in response to MeJA treatment. Data are available via ProteomeXchange with identifier PXD001793. The proteins identified in this study have important biological functions including photosynthesis and energy related proteins (38.4%), protein folding, degradation and regulated proteins (15.0%), stress and defense regulated proteins (11.7%), and redox-responsive proteins (8.3%). The expression levels of four important genes were determined by qRT-PCR analysis. The expression levels of these proteins did not correlate well with their translation levels. To test the defense functions of the differentially expressed proteins, expression vectors of four protein coding genes were constructed to express in-fusion proteins in E. coli. The expressed proteins were used to feed Ostrinia furnacalis, the Asian corn borer (ACB). Our results demonstrated that the recombinant proteins of pathogenesis-related protein 1 (PR1) and thioredoxin M-type, chloroplastic precursor (TRXM) showed the significant inhibition on the development of larvae and pupae. CONCLUSIONS: We found MeJA could not only induce plant defense mechanisms to insects, it also enhanced toxic protein production that potentially can be used for bio-control of ACB.

Identification of microRNAs by small RNA deep sequencing for synthetic microRNA mimics to control Spodoptera exigua.

Beet armyworm, Spodoptera exigua, is a major pest of cotton around the world. With the increase of resistance to Bacillus thuringiensis (Bt) toxin in transgenic cotton plants, there is a need to develop an alternative control approach that can be used in combination with Bt transgenic crops as part of resistance management strategies. MicroRNAs (miRNAs), a non-coding small RNA family (18-25 nt), play crucial roles in various biological processes and over-expression of miRNAs has been shown to interfere with the normal development of insects. In this study, we identified 127 conserved miRNAs in S. exigua by using small RNA deep sequencing technology. From this, we tested the effects of 11 miRNAs on larval development. We found three miRNAs, Sex-miR-10-1a, Sex-miR-4924, and Sex-miR-9, to be differentially expressed during larval stages of S. exigua. Oral feeding experiments using synthetic miRNA mimics of Sex-miR-10-1a, Sex-miR-4924, and Sex-miR-9 resulted in suppressed growth of S. exigua and mortality. Over-expression of Sex-miR-4924 caused a significant reduction in the expression level of chitinase 1 and caused abortive molting in the insects. Therefore, we demonstrated a novel approach of using miRNA mimics to control S. exigua development.

Bacterially expressed double-stranded RNAs against hot-spot sequences of tobacco mosaic virus or potato virus Y genome have different ability to protect tobacco from viral infection.

Posttranscriptional gene silencing, also known as RNA interference, involves degradation of homologous mRNA sequences in organisms. In plants, posttranscriptional gene silencing is part of a defense mechanism against virus infection, and double-stranded RNA is the pivotal factor that induces gene silencing. In this paper, we got seven hairpin RNAs (hpRNAs) constructs against different hot-spot sequences of Tobacco mosaic virus (TMV) or Potato virus Y (PVY) genome. After expression in Escherichia coli HT115, we extracted the seven hpRNAs for the test in tobacco against TMV or PVY infection. The data suggest that different hpRNAs against different hot-spot sequences of TMV or PVY genome had different ability to protect tobacco plants from viral infection. The resistance to TMV conferred by the hpRNA against the TMV movement protein was stronger than other TMV hpRNAs; the resistance to PVY conferred by the hpRNA against the PVY nuclear inclusion b was better than that induced by any other PVY hpRNAs. Northern blotting of siRNA showed that the resistance was indeed an RNA-mediated virus resistance.

[CFU-HPP colony formation of bone marrow hematopoietic proginitor cells in psoriatic patients and methylation of p16 gene promotor in CFU-HPP colony cells].

This study was purposed to investigate the colony formation of high-proliferative potential colony-forming units (CFU-HPP) from bone marrow-derived hematopoietic cells of psoriatic patients and p16 gene promotor methylation in CFU-HPP cells, and to explore the relationship between the colony formation and the methylation status of p16 gene promoter. Bone marrow-derived mononuclear cells from psoriatic patients and normal controls were separated by density gradient centrifugation, and were cultured in methycellulose semi-solid culture medium with SCF, GM-CSF, IL-3 and IL-6 for 14 days to measure the colonies of CFU-HPP. The CFU-HPP colony cells were collected and methylation status of p16 gene promoter of CFU-HPP cell DNA modified with sodium bisulfite was detected by the methylation-specific polymerase chain reaction (MSP). The results showed that in methycellulose semi-solid culture system, the number and the size of CFU-HPP colonies of bone marrow of psoriatic patients were all significantly less than that of normal controls, the positive frequency of p16 gene promoter methylation in CFU-HPP cells was lower than that in CFU-HPP colony cells of normal controls. It is concluded that the colony formation capability of CFU-HPP from bone marrow hematopoietic progenitor cells in psoriatic patients is lower than that in normal controls, and the lower positive frequency of P16 gene promoter methylation in CFU-HPP cells perhaps closely correlated with lower CFU-HPP colony-forming capability.

[Results of surgical treatment for advanced otosclerosis].

OBJECTIVE: To assess the effect of stapes surgery on advanced otosclerosis (AO). METHODS: In 300 cases randomly collected of otosclerosis in 1970 to 1999, 68 cases (77ears) were selected for retrospective analysis, which met the criteria of advanced otosclerosis (mixed deafness, with bone-conduction levels exceeding 40 dB and air-conduction levels exceeding 70 dB in 500 - 2000 Hz). RESULTS: The air-conduction of sixty-eight cases (77 ears) were from 77.32 dB to 53.7 dB (500-2000 Hz) after operation, mean decreased 23.62 dB. Of 71 ears (92.21%) obtained air-conduction improved over 10 dB, of 46 ears (59.74%) gained A-B Gap closure in 10 dB. Air-conduction were from 79.01 dB to 58.23 dB (500 - 4000 Hz) after operation and mean decreased 20.78 dB. Of 68 ears (88.31%) obtained air-conduction improved over 10 dB, of 32 ears (41.56%) gained A-B gap closure in 10 dB. After followed up 5-25 years, of 67 ears were retained stabilization, of 28 ears obtained more improve than postoperation. But 4 ears had drop (all was stapes-elevation and re-improvement after them was reviewed). CONCLUSION: Stapes surgery is effective operation to cured otosclerosis, advanced otosclerosis or far-advanced otosclerosis had greater help to improved hearing.