GmGPDH12,a mitochondrial FAD-GPDH from soybean, increases salt and osmotic stress resistance by modulating redox state and respiration

In plants,glycerol-3-phosphate dehydrogenase(GPDH)catalyzes the interconversion of glycerol-3-phosphate(G3P)and dihydroxyacetone phosphate(DHAP)coupled to the reduction/oxidation of the nicotinamide adenine dinucleotide(NADH)pool,and plays a central role in glycerolipid metabolism and stress response.Previous studies have focused mainly on the NAD+-dependent GPDH isoforms,neglecting the role of flavin adenine dinucleotide(FAD)-dependent GPDHs.We isolated and characterized three mitochondrialtargeted FAD-GPDHs in soybean,of which one isoform(GmGPDH12)showed a significant transcriptional response to NaCl and mannitol treatments,suggesting the existence of a major FAD-GPDH isoform acting in soybean responses to salt and osmotic stress.An enzyme kinetic assay showed that the purified GmGPDH12 protein possessed the capacity to oxidize G3P to DHAP in the presence of FAD.Overexpression and RNA interference of GmGPDH12 in soybean hairy roots resulted in elevated tolerance and sensitivity to salt and osmotic stress,respectively.G3P contents were significantly lower in GmGPDH12-overexpressing hair roots and higher in knockdown hair roots,indicating that GmGPDH12 was essential for G3P catabolism.A significant perturbation in redox status of NADH,ascorbic acid(ASA)and glutathione(GSH)pools was observed in GmGPDH12-knockdown plants under stress conditions.The impaired redox balance was manifested by higher reactive oxygen species generation and consequent cell damage or death;however,overexpressing plants showed the opposite results for these traits.GmGPDH12 overexpression contributed to maintaining constant respiration rates under salt or osmotic stress by regulating mRNA levels of key mitochondrial respiratory enzymes.This study provides new evidence for the roles of mitochondria-localized GmGPDH12 in conferring resistance to salt or osmotic stress by maintaining cellular redox homeostasis,protecting cells and respiration from oxidative injury.

Diversiform gas sensors based on two-dimensional nanomaterials

Two-dimensional(2D)nanomaterials have been widely used in gas sensing due to their large specific surface area,high surface reactivity,and excellent gas adsorption properties.This paper reviews the typical synthesis methods of various types of 2D nanomaterials and summarizes the recent progress in gas sensors based on 2D materials,such as noble metal nanoparticles(NPs),metal oxides(MOS),conductive polymers,other new 2D materials.The methods of doping,modification,and photoexcitation can effectively improve the gas-sensing properties of 2D materials.The sensitive mechanisms of heterojunction,Schottky junction,and photoexcitation in 2D material sensors are discussed in detail.This paper discusses the application prospects of 2D materials in wearable gas sensors,food safety,and self-powered sensing,and provides ideas for further applications in environmental quality monitoring and disease diagnosis.In addition,the opportunities and challenges for gas sensors based on 2D materials are also discussed.

Corridor use by Asian elephants

There are 18 km of Kunming–Bangkok Highway passing through the Mengyang Nature Reserve of Xishuangbanna National Nature Reserve in Yunnan Province,China.From September 2005 to September 2006 the impact of this highway on movement of wild Asian elephants between the eastern and western part of the nature reserve was studied using track transecting,rural surveys and direct monitoring.Our results showed that the number of cross-road corridors used by Asian elephants diminished from 28 to 23 following the construction of the highway.In some areas,the elephant activity diminished or even disappeared,which indicated a change in their home ranges.The utilization rate of artificial corridors was 44%.We also found that elephants prefered artificial corridors that were placed along their original corridors.During the research,wild elephants revealed their adaptation to the highway.They were found walking across the highway road surface many times and for different reasons.We suggest that the highway management bureau should revise their management strategies to mitigate the potential risks caused by elephants on the road for the safety of the public and to protect this endangered species from harm.It is also very important to protect and maintain current Asian elephants corridors in this region.

Molecular Engineering of Novel Fluorophores for High-Contrast Bioimaging

Fluorophores play a significant role in achieving high-contrast imaging in complex physiological environment.Herein,we present the results of our studies on the development of various fluorophores,such as anti-solvatochromic fluorophores,long wavelength emission two-photon fluorophores,large Stokes shift fluorophores and solid-state fluorophores,to achieve high-contrast bioimaging in physiological environments.in this study,we have primarily focused on the design,optical performance,imaging mechanisms,and the applications of these fluorophores with respect to complex physiological conditions.