No abstract

The cytochrome P450 (CYP450) gene family plays a vital role in basic metabolism and enhances plant resistance to stress and pests. However, little information is available on the genome-wide characterization and evolutionary relationship of the CYP450 gene family in Cucumis sativus L. In the present study, a genome-wide bioinformatics analysis was performed, including gene structure, conserved motif, cis-acting promoter element, evolutionary analysis, collinearity, subcellular localization, and expression profile. The gene expression profile of CYP450 was verified using transcriptome sequencing and quantitative reverse transcription polymerase chain reaction. A total of 165 P450 genes were identified in the cucumber genome. These genes were classified into eight subfamilies and unevenly distributed on seven chromosomes. Subcellular localization predicted that most of P450 genes were located in chloroplasts and a few were located on the plasma membrane. CYP450 genes were differentially expressed in different tissues and in response to salicylic acid (SA) treatment. The sizes of all cucumber P450 proteins ranged from 317 to 1,056 aa, the theoretical isoelectric points ranged from 5.05 to 10.31, and the molecular weights ranged from 36,095 to 121,403 KD. This study provides a theoretical basis for further research on the biological functions of the P450 gene in cucumber plants.

Isoetes sinensis Palmer (Isoetaceae) is a critically endangered fern that is a marsh plant (that is an aquatic or amphibious plant) in China. To evaluate damage or influence of lead (Pb) on cell ultrastructure in I. sinensis, we used 2000mg·L-1 Pb(NO3)2 solution to treat I. sinensis for 35d, and used transmission electron microscope (TEM) to observe the cell ultrastructure of leaf blades and roots of the plant. Our results indicated that Pb induced distinct changes of the organelles including chloroplast, mitochondria, nucleolus and vacuole. The level of damage organ was lower leaf > upper leaf > root The typical performance of the damages caused by lead shown that part of the nucleolus cracked; the cristae dilated, matrix vacuolized and membrane structure blurred in mitochondria; the vacuole cracked; grana lamella decreased, stroma lamella loosed, starch grains decreased, and membrane structure was disrupted in chloroplasts; Pb deposits were present on cell wall. The damages to chloroplasts and mitochondria were relatively severe, while damage to the nucleus was relatively lighter. The damage to the cell ultrastructure of leaf blades with direct contact with Pb was more severe than that without direct contact with Pb.

MAP30, a single-stranded type-I ribosome inactivating protein found in Momordica charantia, shows anti-HIV and anti-tumour activity. It could significantly inhibit the HIV-1 and herpes simplex virus infection. In this study, we tried a safe and convenient expression system supplying MAP30 protein for medical practice. The gene encoding MAP30 was cloned into pMD18-T vector. The pMD18-MAP30 plasmid was transformed into competent Escherichia coli JM109 by a chemical method. The MAP30 gene was obtained from the pMD18-MAP30 plasmid digested with NotI and SnaBI and the MAP30 gene was ligated into pGAPHα. Then, pGAPHα-MAP30 was transformed into Pichia pastoris GS115 by electroporation. GS115 transformants were analysed by sodium dodecyl sulfate polyacrylamide gelelectrophoresis (SDS-PAGE) and Western blot. SDS-PAGE revealed an extra band of approximately 32 kDa in the supernatant protein of the GS115 transformants and in their intracellular protein fraction. The result of Western-blot analysis showed that the supernatant and the cell pellet from GS115 with pGAPHα-MAP30 could specially bind to monoclonal antibodies against His in the 32 kDa site. These results demonstrated that the expression of MAP30 in P. pastoris was successful; the process of the expression did not need methanol induction or introduction of an antibiotic-resistance gene. The study may provide a new way for MAP30 synthesis. Owing to its safety, this new approach is expected to be widely used in the medical field.