Comparative Transcriptome Analysis Reveals the Transcriptional Alterations in Growth- and Development-Related Genes in Sweet Potato Plants Infected and Non-Infected by SPFMV, SPV2, and SPVG.

Field co-infection of multiple viruses results in considerable losses in the yield and quality of storage roots in sweet potato. However, little is known about the molecular mechanisms underlying developmental disorders of sweet potato subjected to co-infection by multiple viruses. Here, a comparative transcriptomic analysis was performed to reveal the transcriptional alterations in sweet potato plants infected (VCSP) and non-infected (VFSP) by Sweet potato mild mottle virus (SPFMV), Sweet potato virus Y (SPV2) and Sweet potato virus G (SPVG). A total of 1580 and 12,566 differentially expressed genes (DEGs) were identified in leaves and storage roots of VFSP and VCSP plants, respectively. In leaves, 707 upregulated and 773 downregulated genes were identified, whereas 5653 upregulated and 6913 downregulated genes were identified in storage roots. Gene Ontology (GO) classification and pathway enrichment analysis showed that the expression of genes involved in chloroplast and photosynthesis and brassinosteroid (BR) biosynthesis in leaves and the vitamin biosynthetic process in storage roots was inhibited by co-infection of three viruses: SPFMV, SPV2, and SPVG. This was likely closely related to better photosynthesis and higher contents of Vitamin C (Vc) in storage roots of VFSP than that of VCSP. While some genes involved in ribosome and secondary metabolite-related pathways in leaves and alanine, aspartate, and glutamate metabolism in storage roots displayed higher expression in VCSP than in VFSP. Quantitative real-time PCR analysis demonstrated that the expression patterns of 26 DEGs, including 16 upregulated genes and 10 downregulated genes were consistent with the RNA-seq data from VFSP and VCSP. Taken together, this study integrates the results of morphology, physiology, and comparative transcriptome analyses in leaves and storage roots of VCSP and VFSP to reveal transcriptional alterations in growth- and development-related genes, providing new insight into the molecular mechanisms underlying developmental disorders of sweet potato subjected to co-infection by multiple viruses.

Effects of elevated CO2 and temperature on yield and fruit quality of strawberry (Fragaria × ananassa Duch.) at two levels of nitrogen application.

We investigated if elevated CO(2) could alleviate the negative effect of high temperature on fruit yield of strawberry (Fragaria × ananassa Duch. cv. Toyonoka) at different levels of nitrogen and also tested the combined effects of CO(2), temperature and nitrogen on fruit quality of plants cultivated in controlled growth chambers. Results show that elevated CO(2) and high temperature caused a further 12% and 35% decrease in fruit yield at low and high nitrogen, respectively. The fewer inflorescences and smaller umbel size during flower induction caused the reduction of fruit yield at elevated CO(2) and high temperature. Interestingly, nitrogen application has no beneficial effect on fruit yield, and this may be because of decreased sucrose export to the shoot apical meristem at floral transition. Moreover, elevated CO(2) increased the levels of dry matter-content, fructose, glucose, total sugar and sweetness index per dry matter, but decreased fruit nitrogen content, total antioxidant capacity and all antioxidant compounds per dry matter in strawberry fruit. The reduction of fruit nitrogen content and antioxidant activity was mainly caused by the dilution effect of accumulated non-structural carbohydrates sourced from the increased net photosynthetic rate at elevated CO(2). Thus, the quality of strawberry fruit would increase because of the increased sweetness and the similar amount of fruit nitrogen content, antioxidant activity per fresh matter at elevated CO(2). Overall, we found that elevated CO(2) improved the production of strawberry (including yield and quality) at low temperature, but decreased it at high temperature. The dramatic fluctuation in strawberry yield between low and high temperature at elevated CO(2) implies that more attention should be paid to the process of flower induction under climate change, especially in fruits that require winter chilling for reproductive growth.

[Genetic instability detected by flow cytometry: DNA aneuploid and P16 expression in biopsy specimens from lung cancer].

OBJECTIVE: To investigate DNA aneuploid and P16 expression in biopsy specimens from lung cancer, and to study genetic instability and the application of flow cytometry in lung cancer pernicious degree diagnosis. METHODS: Blood cells and cancer cells in biopsy specimens were marked simultaneously with anti-CD45 and anti-P16 fluorescent antibody, and the ratio of CD45+ P16+ cells and CD4- P16+ cells was compared. DNA content in biopsy specimens from lung cancer was detected by flow cytometry. RESULTS: Among the 74 cases of lung cancer, there are 46 cases of DNA aneuploid (62.2%). Thirty-seven cases of lung cancer expressed P16 lowly (50%). Twelve cases of lung cancer only expressed P16 lowly (16.22%), 21 cases of lung cancer only expressed DNA aneuploid (28.38%), and 25 cases not only expressed P16 lowly but also expressed DNA aneuploid (33.78%). Indexes of malign degree, such as P16 low expression or DNA aneuploid could be detected in 58 cases among the 74 cases (78.38%) by flow cytometry. CONCLUSION: P16 low expression and DNA aneuploid are the indexes of lung cancer malign degree, and flow cytometry can be used to study genetic instability and evaluate biopsy specimens from lung cancer.

[The expression of mutation p53 gene from circulating cancer cells of peripheral blood and the clinical significance in detecting the patients with colorectal cancer].

OBJECTIVE: To study the clinical significance of detecting p53 gene mutation expression in colorectal cancer cells of peripheral blood. METHODS: Flow cytometry (FCM) was used to detect p53 gene mutation expression in peripheral blood cancer cells of 128 patients with colorectal cancer. Experimental data were analyzed by SPSS (v.11.0) software. RESULTS: The lymph node metastasis showed the significant difference statistically (P<0.01) between p53 positive and negative expression in the colorectal cancer patients. The mutation p53 expression associated with existing histological differentiation (r=0.8476, P<0.05). A lymph node metastasis difference was observed between left and right colorectal cancers of mutation p53 positive expression. CONCLUSION: Detecting the mutation p53 expression in cancer cells of peripheral blood might be helpful to the early diagnosis of colorectal cancer.

[Effect of IL-6/sIL-6R on ex vivo expansion of human cord blood derived CD34+ cells].

BACKGROUND & OBJECTIVE: Hematopoietic stem cells (HSC) have the ability of regeneration, differentiation, and reconstructing hematopoietic function, and it is widely used in many fields such as hematopoietic stem cell transplantation, immune therapy, gene therapy and so on. Human cord blood (CB) is abundant of HSC. But a single collection of CB has only a limited amount of HCS and cannot fit the clinical and research use. Thus ex vivo expansion of human CB derived HSC is important. We know that there are some cytokines, which can synergize for enhancing the expansion of CB derived CD34(+) cells in vitro. Currently, some experiments have discovered that IL-6/sIL-6R or its chimera can enhance the ex vivo expansion of CD34(+)gp130+IL-6R- subpopulation. This study was designed to observe the effect of IL-6/sIL-6R on the ex vivo expansion of human CB derived CD34(+) cells, and explore the optimal cytokine combinations. METHODS: Human CB derived CD34(+) cells were isolated by Mini MACS and cultured in ex vivo liquid media in the presence of different cytokine cocktails for 7 or 14 days. After cultured on the seventh or the fourteenth day, the total number of the cultured cells were counted, the ratio of the CD34(+) cell were assayed by flow cytometry (FCM) and the number of it were calculated, and CFU-GM were cultured, then the effects of different cytokine combinations on the ex vivo expansion of CD34(+) cells were compared. In line with the different cytokine cocktails, our experiment divided into five groups: (A) control,(B) SCF,(C) IL-6/sIL-6R+SCF,(D) IL-6/sIL-6R+SCF+FL,and (E) SCF+FL. RESULTS: After cultured in vitro for 7 or 14 days, (1) the number of CD34(+) cells descended apparently in groups A and B; (2) the number of nucleated cells and CD34(+) cells after cultural on the seventh or the fourteenth day increased 7.1+/-2.4 folds, 39.0+/-14.0 folds; 1.8+/-0.7 folds, 4.8+/-2.4 folds, respectively in group C; 16.5+/-5.7 folds, 110.0+/-28.0 folds; 3.5+/-1.5 folds, 10.2+/-4.2 folds in Group D; 17.3+/-3.8 folds, 104.0+/-21.0 folds; 3.6+/-2.1folds, 8.4+/-3.5 folds in Group E. The expansion effects of group C, D, and E were all superior to the group A or B (P< 0.01). The expansion effects of group D and E were superior to group C (P< 0.01). But there was no difference between group D and E (P >0.05); (3) Adding the concentration of sIL-6R to 400 ng/ml, the number of nucleated and CD34(+) cells increased 24.0+/-4.8 folds and 5.6+/-1.2 folds in group D after cultured for seven days superior to group E (P< 0.05). CONCLUSION: IL-6/sIL-6R, SCF, FL can synergize for enhancing the ex vivo expansion of human CB derived CD34(+) cells. But this synergetic effect depends on the concentration of sIL-6R.