Functional identification of MdSMXL8.2,the homologous gene of strigolactones pathway repressor protein gene in Malus×domestica

A homologous gene of strigolactones repressor protein gene SMXL7/D53,MdSMXL8.2(GenBank accession No.:MD07G1222400),was cloned from‘Royal Gala’apple(Malus×domestica Borkh.)in this study.The sequence analysis revealed that the length of this gene was 3243 bp,which encoded 1080 amino acids,and had a protein molecular mass of∼110 kD.The phylogenetic tree analysis indicated that the MdSMXL8.2 exhibited the highest sequence similarity with Arabidopsis AtSMXL7.The protein conserved domain analysis revealed that the MdSMXL8.2 contained two ClpA domains.The prediction of the secondary and tertiary structures of the MdSMXL8.2 indicated that it contained 34.54%αhelix,3.43%β-sheet,and 11.76%extended chain.The in-silico analysis suggested that the promoter sequence of MdSMXL8.2 contained several typical cisacting elements,including abscisic acid(ABA),gibberellin(GA),ethylene,auxin,jasmonic acid(JA),salicylic acid(SA),drought,and heat stressresponsive elements.Quantitative real-time(qRT)-PCR analyses revealed that MdSMXL8.2 was expressed in different apple tissues,with the highest transcript level found in the stem.The expression of MdSMXL8.2 was significantly induced by exogenous ABA,PEG and mannitol,while exogenous NaCl significantly inhibited MdSMXL8.2 expression.The growing status of MdSMXL8.2-overexpressed Orin apple callus was worse than the wild type(WT)after NaCl treatment and had a higher malondialdehyde(MDA)content and relative conductance(REC).Additionally,MdSMXL8.2-overexpressed Arabidopsis exhibited shorter root length and a reduction in fresh weight under salt stress,indicating that MdSMXL8.2 negatively regulated salt tolerance in apples.

Plant community dynamics during the growing season of typical ecosystems on the Tibetan Plateau

The relationships between vegetation and environmental factors have always been a core concern of ecologists.The dynamic characteristics of plant communities during the growing season can directly reflect these relation-ships,so we examined this issue for three typical ecosystems on the Tibetan Plateau.During the growing season,the dominant species remained stable while non-dominant species changed significantly in the alpine meadow and alpine steppe and a mono-dominant community was found in the temperate desert shrub.Due to the seasonal variations of temperature and soil water content,plant species diversity varied significantly during the growing season.Patrick richness,Pielou evenness and Simpson diversity indices differed significantly in the alpine meadow and alpine steppe.The total biomass of these three ecosystems was the largest during the middle growing season.Biomass was greater in the alpine meadow than the alpine steeps or temperature desert.The root-to-shoot ratio was the lowest during the middle growing season for the alpine meadow and alpine steppe and largest during the early growing season for temperate desert shrub.RDA showed the belowground and total biomass were greatly affected by soil physicochemical factors.Multiple linear stepwise regression showed the above ground biomass was greatly affected by relative atmospheric humidity and belowground and total biomass were greatly affected by soil organic carbon,total nitrogen at 0-20 cm soil depth and pH at 10-20 cm soil depth.These findings pro-vide insights into understanding the relationships between vegetation and environmental factors and promote the sustainable utilization of local grasslands on the Tibetan Plateau.

A novel mesenchymal stem cell-based regimen for acute myeloid leukemia differentiation therapy

Currently the main treatment of acute myeloid leukemia(AML)is chemotherapy combining hematopoietic stem cell transplantation.However,the unbearable side effect of chemotherapy and the high risk of life-threatening infections and disease relapse following hematopoietic stem cell transplantation restrict its application in clinical practice.Thus,there is an urgent need to develop alternative therapeutic tactics with significant efficacy and attenuated adverse effects.Here,we revealed that umbilical cord-derived mesenchymal stem cells(UC-MSC)efficiently induced AML cell differentiation by shuttling the neutrophil elastase(NE)-packaged extracellular vesicles(EVs)into AML cells.Interestingly,the generation and release of NE-packaged EVs could be dramatically increased by vitamin D receptor(VDR)activation in UC-MSC.Chemical activation of VDR by using its agonist 1a,25-dihydroxyvitamin D3 efficiently enhanced the pro-differentiation capacity of UC-MSC and then alleviated malignant burden in AML mouse model.Based on these discoveries,to evade the risk of hypercalcemia,we synthetized and identified sw-22,a novel non-steroidal VDR agonist,which exerted a synergistic prodifferentiation function with UC-MSC on mitigating the progress of AML.Collectively,our findings provided a non-gene editing MSC-based therapeutic regimen to overcome the differentiation blockade in AML.

Automatic identifcation of building structure types using unmanned aerial vehicle oblique images and deep learning considering facade prior knowledge

Building structural type information is the foundation for seismic risk assessment and management since it reflects the behavior of buildings under seismic load.However,in earthquake-prone regions,most of this information is out-of-date or nonexistent.This paper proposes a deep learning-based method for automatically identifying building structural types from unmanned aerial vehicle(UAV)oblique images.The method consists of four steps:(1)collect facades of buildings with different structural types by web crawler technology as a sample set;(2)construct a convolutional neural network with a facade prior knowledge attention branch and train the model using the sample set;(3)extract building facades from UAV oblique images based on the georeferencing results of feature points as the test set;(4)identify building structural types by inputting the test set into the trained model.Three cases have been selected to verify the feasibility and applicability of the method.The average recall rate of 85%and the average F1 score of 83%have been achieved in areas with regular building distribution.This method integrates multidisciplinary knowledge to provide a solution for rapid collection of building vulnerability information,and expands the role of oblique photography data in urban management and disaster prevention planning.

Responsive and self-healing structural color supramolecular hydrogel patch for diabetic wound treatment

The treatment of diabetic wounds remains a great challenge for medical community.Here,we present a novel structural color supramolecular hydrogel patch for diabetic wound treatment.This hydrogel patch was created by using N-acryloyl glycinamide(NAGA)and 1-vinyl-1,2,4-triazole(VTZ)mixed supramolecular hydrogel as the inverse opal scaffold,and temperature responsive poly(N-isopropylacrylamide)(PNIPAM)hydrogel loaded with vascular endothelial cell growth factor(VEGF)as a filler.Supramolecular hydrogel renders hydrogel patch with superior mechanical properties,in which NAGA and VTZ also provide self-healing and antibacterial properties,respectively.Besides,as the existence of PNIPAM,the hydrogel patch was endowed with thermal-responsiveness property,which could release actives in response to temperature stimulus.Given these excellent performances,we have demonstrated that the supramolecular hydrogel patch could significantly enhance the wound healing process in diabetes rats by downregulating the expression of inflammatory factors,promoting collagen deposition and angiogenesis.Attractively,due to responsive optical property of inverse opal scaffold,the hydrogel patch could display color-sensing behavior that was suitable for the wound monitoring and management as well as guidance of clinical treatment.These distinctive features indicate that the presented hydrogel patches have huge potential values in biomedical fields.

Liver spheroids on chips as emerging platforms for drug screening

Liver plays a critical role in drug metabolism and nowadays multi-cellular culture systems aiming at imitating liver-specific morphology and functionality are advancing robustly.Numerous immortalized or stem cell-induced hepatic cell lines have been investigated to enhance the hepatic phenotype in establishing co-culture systems.Owing to the robust progresses of microtechnology and bioengineering,two-dimensional(2D)co-cultures such as sandwich culture and micropatterned co-culture systems have emerged.Controllably arranging the hepatocytes and fibroblasts allows bio-mimic homotypic and heterotypic interactions,and the miniaturized co-culture platform realizes high-throughput and sensitive drug screening.Yet,to address the rapid dedifferentiation and the decreased maintenance of hepatic functions existing in 2D cellular systems,various three-dimensional(3D)and dynamic hepatocyte co-culturing formats have been established to obtain more physiologically relevant liver microsystems and prolonged hepatic functionalities,such as spheroid barcodes,liver organoids,bioengineered hepatic spheroids,and microfluidic perfused liver-on-a-chip.In this review,we first introduce the typical structural color spheroid barcodes which facilitate multiple screening and testing.Then we sketch various advances in liver-imitating cellular co-culture protocols through representative examples.Meanwhile,we summarize current difficulties and propose the prospects of bioengineered liver-on-barcode systems for reliable and high-throughput drug screening.