Clay nanosheet-mediated delivery of recombinant plasmids expressing artificial miRNAs via leaf spray to prevent infection by plant DNA viruses

Whitefly-transmitted begomoviruses are economically important plant pathogens that cause severe problems in many crop plants,such as tomato,papaya,cotton,and tobacco.Tomato yellow leaf curl virus(TYLCV)is a typical monopartite begomovirus that has been extensively studied,but methods that can efficiently control begomoviruses are still scarce.In this study,we combined artificial microRNA(amiRNA)-mediated silencing technology and clay nanosheetmediated delivery by spraying and developed a method for efficiently preventing TYLCV infection in tomato plants.We designed three amiRNAs that target different regions of TYLCV to silence virus-produced transcripts.Three plant expression vectors expressing pre-amiRNAs were constructed,and recombinant plasmid DNAs(pDNAs)were loaded onto nontoxic and degradable layered double hydroxide(LDH)clay nanosheets.LDH nanosheets containing multiple pDNAs were sprayed onto plant leaves.We found that the designed amiRNAs were significantly accumulated in leaves 7 days after spraying,while the pDNAs were sustainably detected for 35 days after the spray,suggesting that the LDH nanosheets released pDNAs in a sustained manner,protected pDNAs from degradation and efficiently delivered pDNAs into plant cells.Importantly,when the LDH nanosheets coated with pDNAs were sprayed onto plants infected by TYLCV,both the disease severity and TYLCV viral concentration in sprayed plants were significantly decreased during the 35 days,while the levels of H_(2)O_(2) were significantly increased in those plants.Taken together,these results indicate that LDH nanosheets loaded with pDNAs expressing amiRNAs can be a sustainable and promising tool for begomovirus control.

Transcriptional regulation of bark freezing tolerance in apple(Malus domestica Borkh.)

Freezing tolerance is a significant trait in plants that grow in cold environments and survive through the winter.Apple(Malus domestica Borkh.)is a cold-tolerant fruit tree,and the cold tolerance of its bark is important for its survival at low temperatures.However,little is known about the gene activity related to its freezing tolerance.To better understand the gene expression and regulation properties of freezing tolerance in dormant apple trees,we analyzed the transcriptomic divergences in the bark from 1-year-old branches of two apple cultivars,“Golden Delicious”(G)and“Jinhong”(H),which have different levels of cold resistance,under chilling and freezing treatments.“H”can safely overwinter below−30℃in extremely low-temperature regions,whereas“G”experiences severe freezing damage and death in similar environments.Based on 28 bark transcriptomes(from the epidermis,phloem,and cambium)from 1-year-old branches under seven temperature treatments(from 4 to−29°C),we identified 4173 and 7734 differentially expressed genes(DEGs)in“G”and“H”,respectively,between the chilling and freezing treatments.A gene coexpression network was constructed according to this expression information using weighted gene correlation network analysis(WGCNA),and seven biologically meaningful coexpression modules were identified from the network.The expression profiles of the genes from these modules suggested the gene regulatory pathways that are responsible for the chilling and freezing stress responses of“G”and/or“H.”Module 7 was probably related to freezing acclimation and freezing damage in“H”at the lower temperatures.This module contained more interconnected hub transcription factors(TFs)and cold-responsive genes(CORs).Modules 6 and 7 contained C-repeat binding factor(CBF)TFs,and many CBF-dependent homologs were identified as hub genes.We also found that some hub TFs had higher intramodular connectivity(KME)and gene significance(GS)than CBFs.Specifically,most hub TFs in modules 6 and 7 were activated at the beginning of the early freezing stress phase and maintained upregulated expression during the whole freezing stress period in“G”and“H”.The upregulation of DEGs related to methionine and carbohydrate biosynthetic processes in“H”under more severe freezing stress supported the maintenance of homeostasis in the cellular membrane.This study improves our understanding of the transcriptional regulation patterns underlying freezing tolerance in the bark of apple branches.

Identification and characterization of FpRco1 in regulating vegetative growth and pathogenicity based on T-DNA insertion in Fusarium pseudograminearum

Fusarium pseudograminearum is a devastating pathogen that causes Fusarium crown rot(FCR)in wheat and poses a significant threat to wheat production in terms of grain yield and quality.However,the mechanism by which F.pseudograminearum infects wheat remains unclear.In this study,we aimed to elucidate these mechanisms by constructing a T-DNA insertion mutant library for the highly virulent strain WZ-8A of F.pseudograminearum.By screening this mutant library,we identified nine independent mutants that displayed impaired pathogenesis in barley leaves.Among these mutants,one possessed a disruption in the gene FpRCO1 that is an ortholog of Saccharomyces cerevisiae RCO1,encoding essential component of the Rpd3S histone deacetylase complex in F.pseudograminearum.To further investigate the role of FpRCO1 in F.pseudograminearum,we employed a split-marker approach to knock out FpRCO1 in F.pseudograminearum WZ-8A.FpRCO1 deletion mutants exhibit reduced vegetative growth,conidium production,and virulence in wheat coleoptiles and barley leaves,whereas the complementary strain restores these phenotypes.Moreover,under stress conditions,the FpRCO1 deletion mutants exhibited increased sensitivity to NaCl,sorbitol,and SDS,but possessed reduced sensitivity to H_(2)O_(2)compared to these characteristics in the wild-type strain.RNA-seq analysis revealed that deletion of FpRCO1 affected gene expression(particularly the downregulation of TRI gene expression),thus resulting in significantly reduced deoxynivalenol(DON)production.In summary,our findings highlight the pivotal role of FpRCO1 in regulating vegetative growth and development,asexual reproduction,DON production,and pathogenicity of F.pseudograminearum.This study provides valuable insights into the molecular mechanisms underlying F.pseudograminearum infection in wheat and may pave the way for the development of novel strategies to combat this devastating disease.

DeST 3.0:A new-generation building performance simulation platform

Buildings contribute to almost 30%of total energy consumption worldwide.Developing building energy modeling programs is of great significance for lifecycle building performance assessment and optimization.Advances in novel building technologies,the requirements of high-performance computation,and the demands for multi-objective models have brought new challenges for building energy modeling software and platforms.To meet the increasing simulation demands,DeST 3.0,a new-generation building performance simulation platform,was developed and released.The structure of DeST 3.0 incorporates four simulation engines,including building analysis and simulation(BAS)engine,HVAC system engine,combined plant simulation(CPS)engine,and energy system(ES)engine,connected by air loop and water loop balancing iterations.DeST 3.0 offers numerous new simulation features,such as advanced simulation modules for building envelopes,occupant behavior and energy systems,cross-platform and compatible simulation kernel,FMI/FMU-based co-simulation functionalities,and high-performance parallel simulation architecture.DeST 3.0 has been thoroughly evaluated and validated using code verification,inter-program comparison,and case-study calibration.DeST 3.0 has been applied in various aspects throughout the building lifecycle,supporting building design,operation,retrofit analysis,code appliance,technology adaptability evaluation as well as research and education.The new generation building simulation platform DeST 3.0 provides an efficient tool and comprehensive simulation platform for lifecycle building performance analysis and optimization.

A novel dephosphorylation targeting chimera selectively promoting tau removal in tauopathies

Intraneuronal accumulation of hyperphosphorylated tau is a hallmark pathology shown in over twenty neurodegenerative disorders,collectively termed as tauopathies,including the most common Alzheimer's disease(AD).Therefore,selectively removing or reducing hyperphosphorylated tau is promising for therapies of AD and other tauopathies.Here,we designed and synthesized a novel DEPhosphorylation TArgeting Chimera(DEPTAC)to specifically facilitate the binding of tau to Ba-subunit-contalning protein phosphatase 2A(PP2A-Ba),the most active tau phosphatase in the brain.The DEPTAC exhibited high efficiency in dephosphorylating tau at multiple AD-associated sites and preventing tau accumulation both in vitro and in vivo.Further studies revealed that DEPTAC significantly improved microtubule assembly,neurite plasticity,and hippocampus-dependent learning and memory in transgenic mice with inducible overexpression of truncated and neurotoxic human tau N368.Our data provide a strategy for selective removal of the hyperphosphorylated tau,which sheds new light for the targeted therapy of AD and related-tauopathies.