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1.
Catharanthus roseus contains vincristine and vinblastine, which are outstanding drugs for cancer. In the biosynthetic pathways of terpenoid indole alkaloids (TIAs) in C. roseus, deacetylvindoline 4-O-acetyltransferase (DAT) is a key enzyme that catalyses the last reaction of vindoline biosynthesis to form vinblastine and vincristine. In this study, the CrDAT transgene was transferred into the periwinkle by Agrobacterium-mediated transformation and generated transgenic periwinkle lines with an increase in vincristine accumulation. The C. roseus DAT gene was introduced into C. roseus plants and it was confirmed that CrDAT was successfully transferred into the genome of periwinkle plants and efficiently translated to synthesise recombinant DAT protein. Four transgenic periwinkle lines in T1 generation, T1-1, T1-3, T1-6, and T1-7, expressed recombinant DAT protein with the total protein content in the range of 2.86 μg.mg?1 to 5.12 μg.mg?1. Moreover, the vincristine contents of four transgenic lines increased by 1.63?2.48-fold compared to non-transgenic plants, ranging from 6.91 µg.g?1 (fresh weight) to 10.53 µg.g?1 (fresh weight). The T1-1 line had the highest vincristine content. Hence, the overexpression of the recombinant DAT protein can improve the vincristine accumulation of transgenic C. roseus plants.

Abbreviation: CrDAT - Catharanthus roseus Deacetylvindoline-4-O-Acetyl Transferase; D4H - Deacetoxyvindoline 4-hydroxylase; ELISA - Enzyme-Linked Immunosorbent Assay Monoterpene indole alkaloid; T0, T1 - Generations of transgenic plants; TIAs - Terpenoid indole alkaloids; WT- The wild-type tobacco plants (non transgenic plant); 35S - Cauliflower mosaic virus 35S promoter  相似文献   
2.
Milt quality of Waigieu seaperch was sampled at the beginning, the middle, and the end of the spawning season to assess if the sampling season has an effect on milt quality parameters. The milt volume and total sperm production were higher at the middle of the spawning season while the sperm concentration in milt was significantly higher at the beginning and the end of the spawning season. Sperm morphology and the major parameters of seminal plasma (pH, total protein, Mg2+, or Ca2+ concentrations) did not differ throughout the spawning season. The concentrations of Na+ and the osmolality increased throughout the spawning season. The percentage of motile cells did not differ during the spawning season while the duration of sperm motility (swimming duration) and velocity (swimming speed) were significantly different during the spawning season. The fertilization rate (75.7 ± 6.8%) and hatching rate (56.5 ± 3.1%) at the middle of the spawning season were higher than at the beginning and end periods. Results indicated that milt quality parameters and fertility success in the middle of the spawning season were higher compared to earlier and later sampling dates. Thus, we recommend collecting milt during this time for maximal fertilization and hatching success.  相似文献   
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三年来作者对于幼龄結果油棕的果穗和果实腐烂的症状、分布、蔓延为害,其发生条件和栽培管理的关系进行了詳細的調查和观察,并进行了病原分离、培养、田间人工接种和試探性化学保护等試驗。同时对果实离层組織的形成进行了切片检查。 結果指出海南十二个地区的幼龄结实棕园普遍出現的花、果、穗腐与环境条件和栽培管理有密切关系。果腐是果实离体后从蒂部組織开始的。从腐果組織中經常可以分离到細菌、炭疽菌和鐮刀菌。多次田間接种証明这些菌对健康果实和果穗均无致病能力。大田喷药无效。看来,油棕果腐病是由于环境坏、管理差的条件下,未成熟或接近成熟的果实产生离层而与果柄分离,再由外界杂菌腐食脫果而致腐烂。可見,本病是屬于非侵染性的生理病害。  相似文献   
5.
In this study, signaling pathways and key differentially expressed genes (DEGs) involved in lipid metabolism in muscle and fat tissues were investigated. Muscle and abdominal fat tissues were obtained from 35-day-old female broilers for RNA sequencing. DEGs between muscle and fat tissues were identified. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses of DEGs were performed. A total of 6130 DEGs were identified to be significantly enriched in 365 GO terms, most of which were involved in biological processes, cellular components, and molecular functions in muscle and fat tissues. Three important lipid signaling pathways (pyruvate metabolism, the insulin signaling pathway, and the adipocytokine signaling pathway) were identified among the fat and muscle tissues of broilers. The key common DEGs in these pathways included phosphoenolpyruvate carboxykinase 2 (PCK2), acetyl-CoA carboxylase 1 alpha and beta (ACACA and ACACB), and the mitogen-activated protein kinase (AMPK) gene family. Hence, our findings revealed the pathways and key genes and gene families involved in the regulation of fat deposition in the muscle and fat tissues of broilers.  相似文献   
6.
Thyroxin (T4) is proven to have various functions in fish reproduction. In this study, we investigated oocyte maturation and spawning performance in the rabbit fish, Siganus guttatus, orally exposed to different doses of T4 (0.05, 0.25, and 0.5 mg/kg fish) during vitellogenesis. No statistically significant differences of reproductive characteristics were observed among the treatments. However, the group that was exposed to the dose of 0.5 mg/kg spawned after receiving a hormone injection. The findings suggest that feeding T4 during vitellogenesis did not advance oocyte maturation, but probably could induce spawning in rabbit fish. In a separate experiment, we investigated the effects of orally administered domperidone (DOM) on reproductive performances of the female rabbit fish. The study showed that oral administration of DOM during the early stages of the reproductive cycle had no significant effects on oocyte maturation and spawning performance. Overall, these findings suggest that DOM may not be needed for the induction of maturation and spawning of this species under aquaculture conditions. These practical investigations were conducted with a view to attempt reducing drug use, production costs, and support sustainable aquaculture.  相似文献   
7.
The Chinese box orange (Severinia buxifolia) was shown by graft-inoculation and psyllid-transmission tests to be an alternative host of the bacterium causing citrus Huanglongbing (HLB). A PCR-based assay for detection of the HLB bacterium (HLBB) was used to monitor HLBB. In graft-inoculation tests, the Chinese box orange (CBO) grafted with HLBB-infected scions of Luchen sweet orange (LSO) were positive for HLBB, 2–3 months after grafting. The back-grafting test demonstrated that HLBB-infected CBO scions could transmit HLBB back to LSO hosts via grafting. In psyllid-transmission tests, psyllids (insect vectors) transmitted HLBB to CBO plants, in which HLBB could be detected 3–4 months after inoculation. Acquisition-access tests of psyllids revealed that HLBB-free psyllids can acquire HLBB from diseased CBO hosts and can transmit HLBB back to the LSO plants. A field survey verified the presence of HLBB-infected CBO plants in the vicinity of citrus orchards. In this paper, CBO is shown to be a susceptible host plant in which HLBB can exist and replicate. It is also a donor plant from which HLBB can be transmitted to citrus hosts by grafting or by psyllid vectors.  相似文献   
8.
Monoclonal antibodies (MAbs) were prepared against avian reovirus S1133 protein sigmaA (esigmaA) synthesized in Escherichia coli. MAbs were characterized and used to develop a diagnostic test. Ten MAbs were selected for competitive binding assay following coupling with horseradish peroxidase. The results indicated that these MAbs delineated two epitopes I and II of esigmaA. An immuno-dot binding assay was used to detect the effect of denaturation on antibody recognition of the epitopes. All MAbs bound to esigmaA in its native form. After denaturation by boiling in SDS and 2-mercaptoethanol, the binding of MAbs recognizing epitope I was fully abolished. However, the reactivity of MAbs recognizing epitope II was not affected. MAbs 31 and 32, recognizing epitopes I and II, respectively, were selected for the cross-reactivity to heterologous reovirus strains. The results suggest that the two epitopes are highly conserved among these virus strains. A MAb capture enzyme-linked immunosorbent assay (ELISA) procedure was developed using MAbs 32 and 31 to detect reovirus protein sigmaA in samples from tendon tissues of infected bird and chicken embryo fibroblast (CEF) cell cultures. Avian reovirus sigmaA antigens in tendon specimens were detected from the inoculated birds as early as 2 days post-inoculation (PI), approximated a peak at 7 days PI, and maintained this until 16 days PI, then decreased gradually. A clear difference in absorbance values between the tendon samples of the avian reovirus- and mock-infected birds is obtained. Positive results were also obtained from avian reovirus-infected CEF and from the tendon tissues of naturally infected broilers. These results indicated that the MAb capture ELISA is a useful methods for the detection of avian reovirus from chickens suspected to have avian reovirus infections.  相似文献   
9.
Canine transmissible venereal tumor (CTVT) can be allo-transplanted across major histocompatibility complex barriers. The expression of MHC molecules is usually low in the progression (P) stage and then greatly increases during tumor regression (R). We investigated the effects of tumor infiltrating lymphocytes (TIL) on the expression of MHC molecules of CTVT cells. Isolated, viable CTVT cells were inoculated at each of 12 sites (1 x 10(8) CTVT cells per site) on the back of six, mixed-breed dogs. Tumor masses were collected every 2-3 weeks and prepared for histopathologic, immunocytochemistry, flow cytometry and immunoblotting studies. The level of MHC expression on tumor cells from different stages of growth was measured. Initially, expression of MHC I and II molecules in P phase CTVT was low. Twelve weeks post-inoculation (PI), expression increased dramatically and it continued to increase during R phase. Tumor growth slowed after 12 weeks PI and tumors entered R phase around 17 weeks PI. We hypothesize that CTVT evades host immunosurveillance and grows progressively for 12 weeks, when it becomes vulnerable and subject to the host's anti-tumor immune responses. We further demonstrated that R phase, but not P phase, TIL were closely associated with the over-expression of MHC I and II molecules by CTVT cells. The number and proportion of TIL were higher in R phase tumors. Supernatants, from R phase co-cultures (CTVT+TIL) and TIL only, promoted MHC I and II expression on P phase CTVT cells. After culturing alone for 1 month, expression of MHC classes I and II molecules in R phase CTVT cells decreased to the level of P phase CTVT cells. However, the above-mentioned supernatants restored their expression of MHC I and II molecules. In contrast, supernatants from P phase TIL or CTVT cells increased expression slightly or had no effect. Therefore, TIL, not CTVT cells, produce the effective substance (s) to promote the expression of MHC molecules by the tumor cells. Heat treated supernatant was unable to promote the expression of MHC I and II molecules by CTVT cells. In conclusion, TIL isolated from R phase CTVT secreted a heat-sensitive, soluble substance(s) that triggered over-expression of MHC I and II after 12 weeks PI. This caused the tumor to enter R phase and helped stop CTVT growth. Our findings will facilitate the understanding and further investigation of the mechanisms that initiate host immune surveillance against tumors.  相似文献   
10.
Hydroponically grown cucumber (Cucumis sativus) seedlings were inoculated with zoospores of 1 mycoparasitic (Pythium oligandrum) and 2 pathogenic (Pythium aphanidermatum and Pythium group F) Pythium spp. During the first 2 days after inoculation, all the Pythium spp. caused reduction in the root length. However, roots treated with Pythium oligandrum quickly reached the length of the control and on the 8th day, and for the rest of the experimental period, stimulation of root elongation was noted. Pythium oligandrum was not pathogenic on cucumber and no differences in the fresh weights of control and Pythium oligandrum inoculated plants were observed in the course of the experiment. Pythium group F and Pythium aphanidermatum were pathogenic on cucumber seedlings, but their pathogenicities differed. Thus, while Pythium group F had a constant, negative influence on root length and plant growth, measured as fresh weight, Pythium aphanidermatum caused generalized necroses of the root system, inhibiting consistently root elongation and plant growth and finally causing plant death. Moreover, the zoospores of 2 mycoparasitic species, Pythium oligandrum and Pythium periplocum, were not attracted to roots of cucumber and accumulated on the roots in very low numbers compared to those of the pathogenic species, Pythium aphanidermatum, which were strongly attracted and accumulated in large numbers. Finally, it was also found that Pythium oligandrum colonized the roots very poorly, while Pythium group F and Pythium aphanidermatum were significantly better root colonizers. The significance of these findings is discussed in relation to the ecology of Pythium species and biocontrol.  相似文献   
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