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Despite cold stress is a critical environmental condition that influences the growth and development of bell pepper (Capsicum annuum L.), the underlying molecular mechanism remains unclear. This study aimed to explore the genes associated with the low temperature stress response in bell pepper. Bell pepper ‘Zhongjiao NO.4’ (CRC, cold resistance cultivar) and ‘Zhong 30’ (WT, cold sensitive variety) was used in this study. CRC was grown under 4°C for 0 h (Low), 8 h (Low 8), 16 h (Low 16), and 24 h (Low 24), as well as WT was also grown under 4°C. The transcriptome profile of bell pepper was obtained through Illumina RNA-sequencing. The differentially expressed genes (DEGs) between Low and WT groups were explored, and DEGs between every two groups of Low, Low8, Low16, and Low24 were also screened. Time series clustering analysis of DEGs among Low groups was performed. Functional enrichment analysis of DEGs was conducted by using cluster Profiler package, followed by protein-protein interaction (PPI) analysis. The results showed that DEGs in CRC were involved in flavonoid biosynthesis and phenylalanine metabolism. Functional enrichment analysis of time-course related DEGs indicated that genes were mainly associated with metabolic process, photosynthesis, and lipid metabolic process. LOC107864131, LOC107857080, and LOC107855212 were considered as hub genes, and played vital role in cold stress in bell pepper. Meanwhile, the expression level of ribosomal proteins-related genes was significantly down-regulated during cold treatment. The dynamic expression changes revealed the regulatory role of genes in cold stress response of bell pepper. Our findings might shed light on the molecular mechanisms related to cold tolerance in bell pepper and provide useful candidate genes for genetic improvement.

Near infrared spectroscopy and the back propagation artificial neural network model in conjunction with backward interval partial least squares algorithm were used to estimate the purchasing price of Enshi yulu young tea shoots. The near-infrared spectra regions most relevant to the tea shoots price model (5700.5–5935.8, 7613.6–7848.9, 8091.8–8327.1, 8331–8566.2, 9287.5–9522.5, and 9526.6–9761.9 cm–1) were selected using backward interval partial least squares algorithm. The first five principal components that explained 99.96% of the variability in those selected spectral data were then used to calibrate the back propagation artificial neural tea shoots purchasing price model. The performance of this model (coefficient of determination for prediction 0.9724; root-mean-square error of prediction 4.727) was superior to those of the back propagation artificial neural model (coefficient of determination for prediction 0.8653, root-mean-square error of prediction 5.125) and the backward interval partial least squares model (coefficient of determination for prediction 0.5932, root-mean-square error of prediction 25.125). The acquisition price model with the combined backward interval partial least squares–back propagation artificial neural network algorithms can evaluate the price of Enshi yulu tea shoots accurately, quickly and objectively.

We examined the expression of vascular endothelial growth factor (VEGF) and characteristics of human neural stem cells after transfection with the lentiviral vector encoding the VEGF 165 gene. The latter gene was amplified from the human breast cancer cell line MCF-7 using RT-PCR; then the target gene was cloned into the pCDH–CMV–MCS-EF1-copGFP, a lentiviral expressing plasmid. After transformation, enzyme digestion led to a correct length of the VEGF165 gene, and DNA sequencing analysis confirmed that the VEGF165 gene sequence was exactly the same as that reported by the GeneBank. Then, the recombinant lentivirus produced by 293T cells and packaging plasmids were transfected into fourthpassage human neural stem cells (NSCs). One week after transfection with pCDH-VEGF165, NSCs expressed VEGF stably, and their proliferation ability significantly increased. Furthermore, human NSCs kept their characteristics and multiple differentiation activity after transfection. Our results indicate that human NSCs can express vascular endothelial growth factor highly and stably via transfection with the lentiviral vector encoding the VEGF165 gene, which may be useful for future research on function recovery after stroke.