Redox Regulation of Salt Tolerance in Eutrema salsugineum by Proteomics.

Salt stress severely restricts plant growth and crop production, which is accompanied by accumulation of reactive oxygen species (ROS) that disturb cell redox homeostasis and oxidize redox-sensitive proteins. Eutrema salsugineum, a halophytic species closely related to Arabidopsis, shows a high level of tolerance to salinity and is increasingly used as a model plant in abiotic stress biology. To understand redox modifications and signaling pathways under salt stress, we used tandem mass tag (TMT)-based proteomics to quantify the salt-induced changes in protein redox modifications in E. salsugineum. Salt stress led to increased oxidative modification levels of 159 cysteine sites in 107 proteins, which play roles in carbohydrate and energy metabolism, transport, ROS homeostasis, cellular structure modulation, and folding and assembly. These lists of unknown redox reactive proteins in salt mustard lay the foundation for future research to understand the molecular mechanism of plant salt response. However, glutathione peroxidase (GPX) is one of the most important antioxidant enzymes in plants. Our research indicates that EsGPX may be involved in regulating ROS levels and that plants with overexpressed EsGPX have much improved salt tolerance.

In situ ground settlement sensor for oil-tank monitoring by combining a fiber-optic low-coherent interferometry with a fine mechanical design.

An in situ robust ground settlement (IR-GS) sensor was designed to meet the requirements for oil-tank health monitoring by combining a low-coherent fiber-optic interferometry with a fine mechanical spline shaft. A floating mirror was mounted on the shaft and moved up and down along with the liquid surface. The liquid-contained chambers were hydraulically connected at the bottom by using a liquid-filled tube. The liquid level inside each chamber was initially at equal level. One of the chambers was fixed on a steady ground point, which was chosen in a surveying point of view and served as a reference. The others were distributed around an oil tank and separated the tank's perimeter into eight equal spans. Thereby, the health states of the oil tank were able to be evaluated based on these sensing results. Interrogation of the sensor was employed via a low-coherent fiber-optic Michelson interferometer. One path of the interferometer was composed by the floating mirror, whereupon a light was reflected. The other path was projected to a mirror that was fixed on a stepping motor. Therefore, the corresponding liquid level could be optically surveyed. Differential settlements between each chamber and the reference served as a measure of how much the liquid level was changed from its initials. Experimental tests demonstrated that this IR-GS design, with the optimized shape and weights of the spline shaft, could overcome the error caused by dust, hysteresis, temperature, etc. and meet the practical requirement in the accuracy of ±0.5mm. A practical application was carried out, and its long-term stability has been proved.

[Study on genetic polymorphism of Platycodon grandiflorum based on barcoding of ITS2].

OBJECTIVE: ITS2 of DNA barcoding was used to study genetic polymorphism of Platycodon grandiflorum. METHOD: Total genomic DNA was isolated from P. grandiflorum. PCR was used to amplified the region of internal transcribed spacer 2 (ITS2), and PCR products were sequenced. The sequences of ITS2 were analyzed and compared by Clustal. The intraspecies genetic distance was calculated based on Kimura 2-parameter model by using MEGA 5.05. The ITS2 sequence of Codonopsis pilosula was used as the outreach value for plants of the genus, and the phylogenic tree used constructed by Neighbor-Joining (NJ) method. RESULT: The K2-P's genetic distance of all samples were ranged from 0 to 0.930. The K2-P's genetic distance of samples at the same area were ranged from 0 to 0.178. The K2-P's genetic distance of samples at different areas were ranged from 0.735 to 0.930. The analytical result showed that the degree of genetic variation were heavy in intraspecies of P. grandiflorum and significantly correlated with geographical location. CONCLUSION: The DNA barcoding of ITS2 can applied to study the intraspecific genetic diversity, it provides a reference for further development of DNA barcoding technology applications.

Integration of transcriptome, proteome and metabolism data reveals the alkaloids biosynthesis in Macleaya cordata and Macleaya microcarpa.

BACKGROUND: The Macleaya spp., including Macleaya cordata and Macleaya microcarpa, are traditional anti-virus, inflammation eliminating, and insecticide herb medicines for their isoquinoline alkaloids. They are also known as the basis of the popular natural animal food addictive in Europe. However, few studies especially at genomics level were conducted on them. Hence, we performed the Macleaya spp. transcriptome and integrated it with iTRAQ proteome analysis in order to identify potential genes involved in alkaloids biosynthesis. METHODOLOGY AND PRINCIPAL FINDINGS: We elaborately designed the transcriptome, proteome and metabolism profiling for 10 samples of both species to explore their alkaloids biosynthesis. From the transcriptome data, we obtained 69367 and 78255 unigenes for M. cordata and M. microcarpa, in which about two thirds of them were similar to sequences in public databases. By metabolism profiling, reverse patterns for alkaloids sanguinarine, chelerythrine, protopine, and allocryptopine were observed in different organs of two species. We characterized the expressions of enzymes in alkaloid biosynthesis pathways. We also identified more than 1000 proteins from iTRAQ proteome data. Our results strongly suggest that the root maybe the organ for major alkaloids biosynthesis of Macleaya spp. Except for biosynthesis, the alkaloids storage and transport were also important for their accumulation. The ultrastructure of laticifers by SEM helps us to prove the alkaloids maybe accumulated in the mature roots. CONCLUSIONS/SIGNIFICANCE: To our knowledge this is the first study to elucidate the genetic makeup of Macleaya spp. This work provides clues to the identification of the potential modulate genes involved in alkaloids biosynthesis in Macleaya spp., and sheds light on researches for non-model medicinal plants by integrating different high-throughput technologies.