Differential pathogenicity of two different recombinant PVYNTN isolates in Physalis floridana is likely determined by the coat protein gene

A previous study has identified two types of recombinant variants of Potato virus Y strain NTN (PVYNTN) in China and sequenced the complete genome of the variant PVYNTN-HN2. In this study, the complete genome of isolate PVYNTN-HN1 was fully sequenced and analyzed. The most striking difference between the two variants was the location of recombinant joint three (RJ3). In PVYNTN-HN1, like other typical European-PVYNTN isolates such as PVYNTN-Hun, the RJ3 was located at nucleotide (nt) 9183, namely the 3' proximal end of the CP gene (nt. 8571-9371), thus leading to most (the first 613 nucleotides from the 5' proximal end) of the CP gene (801 bp) with a PVYN origin and PVYN-serotype; whereas in contrast, the RJ3 in PVYNTN-HN2 was located at nt 8572, consequently leading to a CP gene of PVYO origin and PVYO-serotype. The varied genome composition among PVYO, PVYN, PVYN:O, PVYNTN-HN1 and PVYNTN-HN2 made them useful for the investigation of possible roles of gene segment(s) in symptom formation on host plants. When Physalis floridana plants were infected with different PVY isolates, two types of symptoms were induced. PVYN and PVYNTN-HN1 induced mild symptoms (mainly mild mottling) whereas PVYO, PVYN:O and PVYNTN-HN2 induced serve symptoms including leaf and stem necrosis, leaf-drop and stunting. These results, together with a previous study using artificial PVY chimeras, demonstrate that the CP gene, especially the 5' proximal segment (nt 8572-9183), and/or CP likely determine the pathogenicity of PVY in P. floridana

An efficient protocol of potato virus A eradication by thermotherapy coupled with in vitro culture of potato (Solanum tuberosum)

With the aim of developing an effective protocol for virus elimination from potato (Solanum tuberosum L.) plantlets, thermotherapy coupled with isolating the first nodal cuttings by in vitro culture was successful to potato virus A (PVA) elimination. The survival ratio of potato plantlets was affective by thermotherapy temperatures and durations. The optimal thermotherapy temperature was 36±1 oC with highest survival ratio and effective elimination. The results of RT-PCR indicated that the regenerated plantlets obtained from the first cycle (four weeks) of thermotherapy in daytime at 36±1 oC with light intensity 40 mmole/m/s for 12 hr, and 20±1 oC in darkness for 12 hr had PVA infected. While isolated the first nodal cuttings and followed by thermotherapy at the first cycle conditions for another two weeks, the PVA could be eliminated. Thermotherapy was given by culturing the nodal cutting from the infected of PVA for six weeks in total on MS medium, and the PVA-free plantlets were obtained. In concluded that the protocol of thermotherapy coupled with isolating the first nodal cuttings by in vitro culture in the study can be effectively used for virus free plantlets in potato, and probably also for other vegetable propagated plant species

Transcriptome analysis provides StMYBA1 gene that regulates potato anthocyanin biosynthesis by activating structural genes

Anthocyanin biosynthesis is affected by light, temperature, and other environmental factors. The regulation mode of light on anthocyanin synthesis in apple, pear, tomato and other species has been reported, while not clear in potato. In this study, potato RM-210 tubers whose peel will turn purple gradually after exposure to light were selected. Transcriptome analysis was performed on RM-210 tubers during anthocyanin accumulation. The expression of StMYBA1 gene continued to increase during the anthocyanin accumulation in RM-210 tubers. Moreover, co-expression cluster analysis of differentially expressed genes showed that the expression patterns of StMYBA1 gene were highly correlated with structural genes CHS and CHI. The promoter activity of StMYBA1 was significantly higher in light conditions, and StMYBA1 could activate the promoter activity of structural genes StCHS, StCHI, and StF3H. Further gene function analysis found that overexpression of StMYBA1 gene could promote anthocyanin accumulation and structural gene expression in potato leaves. These results demonstrated that StMYBA1 gene promoted potato anthocyanin biosynthesis by activating the expression of structural genes under light conditions. These findings provide a theoretical basis and genetic resources for the regulatory mechanism of potato anthocyanin synthesis

Molecular characterization of <i>Potato mop-top virus</i> isolates from China and Canada and development of RT-PCR differentiation of two sequence variant groups

<p>The complete genome comprising three genomic RNAs of three Canadian and two Chinese isolates of <i>Potato mop-top virus</i> were sequenced and analysed. Two open reading frames (ORFs) were found in RNA1 of 6.1 kb, encoding a readthrough RNA-dependent RNA polymerase (RdRp). A coat protein (CP)-readthrough protein was encoded by RNA2 of 3.1 kb. Four ORFs that encoded the triple gene block proteins (TGBps) and a cysteine-rich protein were found in RNA3 (2.9 kb) of the Chinese isolate ‘Yunnan’; whereas in the remaining isolates (three Canadian isolates and the Chinese isolate ‘Guangdong’), only three ORFs encoding TGBps were observed in RNA3. A single nucleotide mutation of A₂₄₆₂ to G₂₄₆₂ abolished the start codon ‘AUG’ for the fourth putative ORF in RNA3 of these isolates. Based on phylogenetic and sequence similarity analysis of these isolates as well as those reported by others at the complete RNA sequence level, each of RNA1, RNA2 and RNA3 could be divided into at least two groups. In Canadian isolates ‘Ch9’, ‘Ch10’ and ‘Ch20’ and Chinese isolate ‘Guangdong’, all genomic RNAs belonged to group A; and in Chinese isolate ‘Yunnan’, all of its RNA belonged to group B. Interestingly, in Swedish isolate ‘Sw’, RNA1 and RNA2 belonged to group A while RNA3 belonged to group B. A duplex RT-PCR for differentiating groups A and B of RNA3 was developed and evaluated. All PMTV samples collected in Guangdong, China, and New Brunswick, Canada, possessed a RNA3 belonging to group A; whereas the samples collected in Yunnan, China, possessed a RNA3 belonging to group B.</p

DataSheet_1_Pathological diagnostic nomograms for predicting malignant histology and unfavorable pathology in patients with endophytic renal tumor.docx

PurposeTo develop and validate nomograms for pre-treatment prediction of malignant histology (MH) and unfavorable pathology (UP) in patients with endophytic renal tumors (ERTs).MethodsWe retrospectively reviewed the clinical information of 3245 patients with ERTs accepted surgical treatment in our center. Eventually, 333 eligible patients were included and randomly enrolled into training and testing sets in a ratio of 7:3. We performed univariable and multivariable logistic regression analyses to determine the independent risk factors of MH and UP in the training set and developed the pathological diagnostic models of MH and UP. The optimal model was used to construct a nomogram for MH and UP. The area under the receiver operating characteristics (ROC) curves (AUC), calibration curves and decision curve analyses (DCA) were used to evaluate the predictive performance of models.ResultsOverall, 172 patients with MH and 50 patients with UP were enrolled in the training set; and 74 patients with MH and 21 patients with UP were enrolled in the validation set. Sex, neutrophil-to-lymphocyte ratio (NLR), R score, N score and R.E.N.A.L. score were the independent predictors of MH; and BMI, NLR, tumor size and R score were the independent predictors of UP. Single-variable and multiple-variable models were constructed based on these independent predictors. Among these predictive models, the malignant histology-risk nomogram consisted of sex, NLR, R score and N score and the unfavorable pathology-risk nomogram consisted of BMI, NLR and R score performed an optimal predictive performance, which reflected in the highest AUC (0.842 and 0.808, respectively), the favorable calibration curves and the best clinical net benefit. In addition, if demographic characteristics and laboratory tests were excluded from the nomograms, only the components of the R.E.N.A.L. Nephrometry Score system were included to predict MH and UP, the AUC decreased to 0.781 and 0.660, respectively (P=0.001 and 0.013, respectively).ConclusionIn our study, the pathological diagnostic models for predicting malignant and aggressive histological features for patients with ERTs showed outstanding predictive performance and convenience. The use of the models can greatly assist urologists in individualizing the management of their patients.</p

Electrochemical Determination of Glycoalkaloids Using a Carbon Nanotubes-Phenylboronic Acid Modified Glassy Carbon Electrode

A versatile strategy for electrochemical determination of glycoalkaloids (GAs) was developed by using a carbon nanotubes-phenylboronic acid (CNTs-PBA) modified glassy carbon electrode. PBA reacts with α-solanine and α-chaconine to form a cyclic ester, which could be utilized to detect GAs. This method allowed GA detection from 1 μM to 28 μM and the detection limit was 0.3 μM. Affinity interaction of GAs and immobilized PBA caused an essential change of the peak current. The CNT-PBA modified electrodes were sensitive for detection of GAs, and the peak current values were in quite good agreement with those measured by the sensors