Fat,oil,and grease as new feedstock towards bioelectrogenesis in microbial fuel cells:Microbial diversity,metabolic pathways,and key enzymes

Microbial fuel cells(MFCs)are a well-known technology used for bioelectricity production from the decomposition of organic waste via electroactive microbes.Fat,oil,and grease(FOG)as a new substrate in the anode and microalgae in the cathode were added to accelerate the electrogenesis.The effect of FOG concentrations(0.1%,0.5%,1%,and 1.5%)on the anode chamber was investigated.The FOG degradation,volatile fatty acid(VFAs)production,and soluble chemical oxygen demand along with voltage output kinetics were analyzed.Moreover,the microbial community analysis and active functional enzymes were also evaluated.The maximum power and current density were observed at 0.5%FOG which accounts for 96 mW m^(-2)(8-folds enhancement)and 560 mA m^(-2)(3.7-folds enhancement),respectively.The daily voltage output enhanced upto 2.3-folds with 77.08%coulombic efficiency under 0.5%FOG,which was the highest among all the reactors.The 0.5%FOG was degraded>85%,followed by a 1%FOG-loaded reactor.The chief enzymes inβ-oxidation and electrogenesis were acetyl-CoA C-acetyltransferase,riboflavin synthase,and riboflavin kinase.The identified enzymes symbolize the presence of Clostridium sp.(>15%)and Pseudomonas(>10%)which served as electrochemical active bacteria(EAB).The major metabolic pathways involved in electrogenesis and FOG degradation were fatty acid biosynthesis and glycerophospholipid metabolism.Utilization of lipidic-waste(such as FOG)in MFCs could be a potential approach for simultaneous biowaste utilization and bioenergy generation.

Seasonal variation of airborne fungi of the Tiantishan Grottoes andWestern Xia Museum,Wuwei,China

In this study,a systematic survey of cultural airborne fungi was carried out in the occurrence environments of wall paintings that are preserved in the Tiantishan Grottoes and the Western Xia Museum,China.A bio-aerosol sampler was used for sampling in four seasons in 2016.Culture-dependent and-independent methods were taken to acquire airborne fungal concentration and purified strains;by the extraction of genomic DNA,amplification of fungal ITS rRNA gene region,sequencing,and phylogenetic analysis,thereafter the fungal community composition and distribution characteristics of different study sites were clarified.We disclosure the main environmental factors which may be responsible for dynamic changes of airborne fungi at the sampling sites.The concentration of cultural airborne fungi was in a range from 13 to 1,576 CFU/m^(3),no significant difference between the two sites at the Tiantishan Grottoes,with obvious characteristics of seasonal variation,in winter and spring were higher than in summer and autumn.Also,there was a significant difference in fungal concentration between the inside and outside of the Western Xia Museum,the outside of the museum was far more than the inside of the museum in the four seasons,particularly in the winter.Eight fungal genera were detected,including Cladosporium,Penicillium,Alternaria,and Filobasidium as the dominant groups.The airborne fungal community structures of the Tiantishan Grottoes show a distinct characteristic of seasonal variation and spatial distribution.Relative humidity,temperature and seasonal rainfall influence airborne fungal distribution.Some of the isolated strains have the potential to cause biodeterioration of ancient wall paintings.This study provides supporting information for the pre-warning conservation of cultural relics that are preserved at local sites and inside museums.

Sulfated peptides and their receptors:Key regulators of plant development and stress adaptation

Four distinct types of sulfated peptides have been identified in Arabidopsis thaliana.These peptides play crucial roles in regulating plant development and stress adaptation.Recent studies have revealed that Xan-thomonas and Meloidogyne can secrete plant-like sulfated peptides,exploiting the plant sulfated peptide signaling pathway to suppress plant immunity.Over the past three decades,receptors for these four types of sulfated peptides have been identified,all of which belong to the leucine-rich repeat receptor-like protein kinase subfamily.A number of regulatory proteins have been demonstrated to play important roles in their corresponding signal transduction pathways.In this review,we comprehensively summarize the discov-eries of sulfated peptides and their receptors,mainly in Arabidopsis thaliana.We also discuss their known biological functions in plant development and stress adaptation.Finally,we put forward a number of ques-tions for reference in future studies.

SERK Receptor-like Kinases Control Division Patterns of Vascular Precursors and Ground Tissue Stem Cells during Embryo Development in Arabidopsis

During embryo development, the vascular precursors and ground tissue stem cells divide to renew them-selves and produce the vascular tissue, endodermal cells, and cortical cells. However, the molecular mech-anisms regulating division of these stem cells have remained largely elusive. In this study, we show that loss of function of SOMATIC EMBRYOGENESIS RECEPTOR-UKE KINASE (SERK) genes results in aberrant em-bryo development. Fewer cortical, endodermal, and vascular cells are generated in the embryos of serk1 serk2bak1 triple mutants. WUSCHEL-RELATED HOMBOBOX5 (WOXS) is ectopically expressed in vascular cells of serkl serk2 bak1 embryos. The first transverse division of vascular precursors in mid-globular em-bryos and second asymmetric division of ground tissue stem cells in early-heart embryos are abnormally altered to a longitudinal division. The embryo defects can be partially rescued by constitutively activated mitogen-activated protein kinase (MAPK) kinase kinase YODA (YDA) and MAPK kinase MKK5. Taken together, our results reveal that SERK-mediated signals regulate division patterns of vascular precursors and ground tissue stem cells, likely via the YDA-MKK4/5 cascade, during embryo development.

Conserved and differentiated functions of CIK receptor kinases in modulating stem cell signaling in Arabidopsis

The shoot apical meristem(SAM)and root apical meristem(RAM)act as pools of stem cells that give rise to aboveground and underground tissues and organs in higher plants,respectively.The CLAVATA3(CLV3)-WUSCHEL(WUS)negative-feedback loop acts as a core pathway controlling SAM homeostasis,while CLV3/EMBRYO SURROUNDING REGION(ESR)40(CLE40)and WUSCHEL-RELATED HOMEOBOX5(WOX5),homologs of CLV3 and WUS,direct columella stem cell fate.Moreover,CLV3 INSENSITIVE KINASES(CIKs)have been shown to be essential for maintaining SAM homeostasis,whereas whether they regulate the distal root meristem remains to be elucidated.Here,we report that CIKs are indispensable for transducing the CLE40 signal to maintain homeostasis of the distal root meristem.We found that the cik mutant roots displayed disrupted quiescent center and delayed columella stem cell(CSC)differentiation.Biochemical assays demonstrated that CIKs interact with ARABIDOPSIS CRINKLY4(ACR4)in a ligand-independent manner and can be phosphorylated by ACR4 in vitro.In addition,the phosphorylation of CIKs can be rapidly induced by CLE40,which partially depends on ACR4.Although CIKs act as conserved and redundant regulators in the SAM and RAM,our results demonstrated that they exhibit differentiated functions in these meristems.

The Dof transcription factor COG1 acts as a key regulator of plant biomass by promoting photosynthesis and starch accumulation

Photosynthetic efficiency is the primary determinant of crop yield,including vegetative biomass and grain yield.Manipulation of key transcription factors known to directly control photosynthetic machinery can be an effective strategy to improve photosynthetic traits.In this study,we identified an Arabidopsis gain-of-function mutant,cogwheel1-3D,that shows a significantly enlarged rosette and increased biomass compared with wild-type plants.Overexpression of COG1,a Dof transcription factor,recapitulated the phenotype of cogwheel1-3D,whereas knocking out COG1 and its six paralogs resulted in a reduced rosette size and decreased biomass.Transcriptomic and quantitative reverse transcription polymerase chain reaction analyses demonstrated that COG1 and its paralogs were required for light-induced expression of genes involved in photosynthesis.Further chromatin immunoprecipitation and electrophoretic mobility shift assays indicated that COG1 can directly bind to the promoter regions of multiple genes encoding light-harvesting antenna proteins.Physiological,biochemical,and microscopy analyses revealed that COG1 enhances photosynthetic capacity and starch accumulation in Arabidopsis rosette leaves.Furthermore,combined results of bioinformatic,genetic,and molecular experiments suggested that the functions of COG1 in increasing biomass are conserved in different plant species.These results collectively demonstrated that COG1 acts as a key regulator of plant biomass by promoting photosynthesis and starch accumulation.Manipulating COG1 to optimize photosynthetic capacity would create new strategies for future crop yield improvement.

A reference-grade genome of the xerophyte Ammopiptanthus mongolicus sheds light on its evolution history in legumes and droughttolerance mechanisms

Plants that grow in extreme environments represent unique sources of stress-resistance genes and mechanisms.Ammopiptanthus mongolicus(Leguminosae)is a xerophytic evergreen broadleaf shrub native to semi-arid and desert regions;however,its drought-tolerance mechanisms remain poorly understood.Here,we report the assembly of a reference-grade genome for A.mongolicus,describe its evolutionary history within the legume family,and examine its drought-tolerance mechanisms.The assembled genome is 843.07 Mb in length,with 98.7%of the sequences successfully anchored to the nine chromosomes of A.mongolicus.The genome is predicted to contain 47611 protein-coding genes,and 70.71%of the genome is composed of repetitive sequences;these are dominated by transposable elements,particularly longterminal-repeat retrotransposons.Evolutionary analyses revealed two whole-genome duplication(WGD)events at 130 and 58 million years ago(mya)that are shared by the genus Ammopiptanthus and other legumes,but no species-specific WGDs were found within this genus.Ancestral genome reconstruction revealed that the A.mongolicus genome has undergone fewer rearrangements than other genomes in the legume family,confirming its status as a"relict plant".Transcriptomic analyses demonstrated that genes involved in cuticular wax biosynthesis and transport are highly expressed,both under normal conditions and in response to polyethylene glycol-induced dehydration.Significant induction of genes related to ethylene biosynthesis and signaling was also observed in leaves under dehydration stress,suggesting that enhanced ethylene response and formation of thick waxy cuticles are two major mechanisms of drought tolerance in A.mongolicus.Ectopic expression of AmERF2,an ethylene response factor unique to A.mongolicus,can markedly increase the drought tolerance of transgenic Arabidopsis thaliana plants,demonstrating the potential for application of A.mongolicus genes in crop improvement.

Receptor-Like Kinases:Key Regulators of Plant Development and Defense

Plants are multi-cellular organisms that live in diverse and fluctuating environments. Cell-cell and cell-environment com- munication are therefore critical to plant growth and develop- ment. In animals, transmembrane receptor protein tyrosine kinases play significant roles in cell-cell signaling. There was a great deal of surprise in the plant community, however, when the first receptor-like protein kinase （RLK） was isolated from maize by John C.

Regulation of Brassinosteroid Biosynthesis and Inactivation

Brassinosteroids （BRs） are a group of naturally-occurring steroidal phytohormones playing fundamental roles during normal plant growth and development. Using a combination of experimental approaches, including analytical chemistry, genetics, and biochemistry, the major BR biosynthetic pathway has been largely elucidated. The least-understood knowledge in the BR research field is probably the molecular mechanisms controlling the bioactive levels of BRs in response to various developmental and environmental cues. In this review, we focus our discussion on a recently-proposed, 8-step predominant BR biosynthetic pathway, several newly-identified transcription factors regulating the expression of key enzymes that catalyze BR biosynthesis, and up-to-date information about the mechanisms that plants use to inactivate unnecessary BRs.

Patterns of leaf N:P stoichiometry along climatic gradients in sandy region, north of China

Aims Biological and environmental factors determine geographic patterns of plant nutrient stoichiometry jointly.Unraveling the distribution pattern and the potential drivers of nutrient stoichiometry is therefore critical for understanding the adaptive strategies and biogeochem-istry cycling.Aimed to determine how leaf nitrogen(N):phosphorus(P)stoichiometry is linked to biological and environmental factors,we investigated the patterns of psammophyte leaf N:P stoichiometry in sandy region,northern China,and the potential factors affecting leaf N:P stoichiometry were explored.Methods Based on 10 m×10 m quadrates survey,the leaves of 352 dominant psammophyte samples belonging to 167 species were collected cross a 3000 km east-west transect in sandy environments,north-ern China.The samples were further classified into the following groups on the basis of plant life forms and functional groups(pho-tosynthesis pathways and nitrogen fixation).The structural equation modeling was employed to clarify the importance of biological and environmental factors on leaf N:P stoichiometry.Important Findings Generally,the higher leaf N and P concentrations,but lower N:P ratio were found in psammophyte compared with other ecosystems.Mean annual temperature(MAT)influenced the leaf N,P concentra-tions negatively,while mean annual precipitation(MAP)did posi-tively.MAP played greater influence on leaf N,P concentrations than MAT did.MAP affected leaf N,P concentrations directly or indirectly through phylogeny,while MAT only shown direct effect on leaf N concentration.The psammophyte was more limited by N,rather P,in sandy region of northern China.These results suggest that phylogeny of psammophyte and climate jointly influence leaf N:P stoichiometry,and the results could be helpful in modeling bio-geochemical nutrients cycling in vulnerable ecosystems like sandy environment.

Multi-layered roles of BBX proteins in plant growth and development

Light and phytohormone are external and internal cues that regulate plant growth and development throughout their life cycle.BBXs(B-box domain proteins)are a group of zinc finger proteins that not only directly govern the transcription of target genes but also associate with other factors to create a meticulous regulatory network to precisely regulate numerous aspects of growth and developmental processes in plants.Recent studies demonstrate that BBXs play pivotal roles in light-controlled plant growth and development.Besides,BBXs have been documented to regulate phytohormone-mediated physiological procedures.In this review,we summarize and highlight the multi-faced role of BBXs,with a focus in photomorphogenesis,photoperiodic flowering,shade avoidance,abiotic stress,and phytohormone-mediated growth and development in plant.

Nanofibrils in 3D aligned channel arrays with synergistic effect of Ag/NPs for rapid and highly efficient electric field disinfection

The disinfection of waterborne pathogens from drinking water is extremely important for human health.Although countless efforts have been devoted for drinking water inactivation,challenges still exist in terms of relative high energy consumption and complicated to implement and maintain.Here,silver nanoparticles anchoring wood carbon(Ag NPs/WC)membrane is developed as cost-effective,high flux,scalable filter for highly efficient electric field disinfection of water.Under electric field of 4 V voltage,the designed membrane achieved more than 5 log(99.999%)disinfection performance for different model bacteria,including Escherichia coli(E.coli),Enterococcus faecalis(E.faecalis),Salmonella enterica serovar Typhimirium(S.Typhimurium)and Bacillus subtilis(B.subtilis)with a high flux of 3.8 x 103 L m^(-2)h^(-1),extremely low energy consumption of 2 J L^(-1)m^(-2)and fantastic durability(7 days).The high disinfection performance of Ag NPs/WC membrane is attributed to the synergistic disinfection of carbon nanofibrils,Ag nanoparticles as well as the low tortuous structure of the channels in wood carbon.The Ag NPs/WC membrane presents a promising strategy for point-of-use drinking water electric field disinfection treatment.

Nitrate transporter NRT1.1 and anion channel SLAH3 form a functional unit to regulate nitrate-dependent alleviation of ammonium toxicity

Ammonium(NH_(4)^(+))and nitrate(NO_(3)^(-))are major inorganic nitrogen(N)sources for plants.When serving as the sole or dominant N supply,NH_(4)^(+)often causes root inhibition and shoot chlorosis in plants,known as ammonium toxicity.NO_(3)^(-) usually causes no toxicity and can mitigate ammonium toxicity even at low concentrations,referred to as nitrate-dependent alleviation of ammonium toxicity.Our previous studies indicated a NO_(3)^(-) efflux channel SLAH3 is involved in this process.However,whether additional components contribute to NO_(3)^(-)-mediated NH_(4)^(+)detoxification is unknown.Previously,mutations in NO_(3)^(-) transporter NRT1.1 were shown to cause enhanced resistance to high concentrations of NH_(4)^(+).Whereas,in this study,we found when the high-NH_(4)^(+) medium was supplemented with low concentrations of NO_(3)^(-),nrt1.1 mutant plants showed hyper-sensitive phenotype instead.Furthermore,mutation in NRT1.1 caused enhanced medium acidification under high-NH_(4)^(+)/Iow-NO_(3)^(-) condition,suggesting NRT1.1 regulates ammonium toxicity by facilitating H+uptake.Moreover,NRT1.1 was shown to interact with SLAH3 to form a transporter-channel complex.Interestingly,SLAH3 appeared to affect NO_(3)^(-) influx while NRT1.1 influenced NO_(3)^(-) efflux,suggesting NRT1.1 and SLAH3 regulate each other at protein and/or gene expression levels.Our study thus revealed NRT1.1 and SLAH3 form a functional unit to regulate nitrate-dependent alleviation of ammonium toxicity through regulating NO_(3)^(-) transport and balancing rhizosphere acidification.

PIF4 and HOOKLESS1 Impinge on Common Transcriptome and Isoform Regulation in Thermomorphogenesis

High temperature activates the transcription factor PHYTOCHROME-INTERACTING FACTOR4(PIF4)to stimulate auxin signaling,which causes hypocotyl elongation and leaf hyponasty(thermomorphogenesis).HOOKLESS1(HLS1)is a recently reported positive regulator of thermomorphogenesis,but the molecular mechanisms by which HLS1 regulates thermomorphogenesis remain unknown.In this study,we initially compared PIF4-and/or HLS1-dependent differential gene expression(DEG)upon high-temperature treatment.We found that a large number of genes are coregulated by PIF4 and HLS1,especially genes involved in plant growth or defense responses.Moreover,we found that HLS1 interacts with PIF4 to form a regulatory module and that,among the HLS1-PIF4-coregulated genes,27.7%are direct targets of PIF4.We also identified 870 differentially alternatively spliced genes(DASGs)in wild-type plants under high temperature.Interestingly,more than half of these DASG events(52.4%)are dependent on both HLS1 and PIF4,and the spliceosome-defective mutant plantsexhibit a hyposensitive response to high temperature,indicating that DASGs are required for thermomorphogenesis.Further comparative analyses showed that the HLS1/PIF4-coregulated DEGs and DASGs exhibit almost no overlap,suggesting that high temperature triggers two distinct strategies to control plant responses and thermomorphogenesis.Taken together,these results demonstrate that the HLS1-PIF4 module precisely controls both transcriptional and posttranscriptional regulation during plant thermomorphogenesis.

Actin-depolymerizing factors 8 and 11 promote root hair elongation at high pH

A root hair is a polarly elongated single-celled structure that derives from a root epidermal cell and func-tions in uptake of water and nutrients from the surrounding environment.Previous reports have demon-strated that short periods of high pH inhibit root hair extension;but the effects of long-term high-pH treat-ment on root hair growth are still unclear.Here,we report that the duration of root hair elongation is signicantly prolonged with increasing external pH,which counteracts the effect of decreasing root hair elongation rate and ultimately produces longer root hairs,whereas loss of actin-depolymerizing factor 8 and 11(ADF8/11)function causes shortening of root hair length at high pH(pH 7.4).Accumulation of ADF8/11 at the tips of root hairs is inhibited by high pH,and increasing environmental pH affects the actinlament(F-actin)meshwork at the root hair tip.At high pH,the tip-focused F-actin meshwork is absent in root hairs of the adf8/11 mutant,actinlaments are disordered at the adf8/11 root hair tips,and actin turn-over is attenuated.Secretory and recycling vesicles do not aggregate in the apical region of adf8/11 root hairs at high pH.Together,our results suggest that,under long-term exposure to high extracellular pH,ADF8/11 may establish and maintain the tip-focused F-actin meshwork to regulate polar trafcking of secretory/recycling vesicles at the root hair tips,thereby promoting root hair elongation.

Rational management of the plant microbiome for the Second Green Revolution

The Green Revolution of the mid-20th century transformed agriculture worldwide and has resulted in envi-ronmental challenges.A new approach,the Second Green Revolution,seeks to enhance agricultural pro-ductivity while minimizing negative environmental impacts.Plant microbiomes play critical roles in plant growth and stress responses,and understanding plant–microbiome interactions is essential for developing sustainable agricultural practices that meet food security and safety challenges,which are among the United Nations Sustainable Development Goals.This review provides a comprehensive exploration of key deterministic processes crucial for developing microbiome management strategies,including the host effect,the facilitator effect,and microbe–microbe interactions.A hierarchical framework for plant mi-crobiome modulation is proposed to bridge the gap between basic research and agricultural applications.This framework emphasizes three levels of modulation:single-strain,synthetic community,and in situ mi-crobiome modulation.Overall,rational management of plant microbiomes has wide-ranging applications in agriculture and can potentially be a core technology for the Second Green Revolution.

Heat stress-induced decapping of WUSCHEL mRNA enhances stem cell thermotolerance in Arabidopsis

The plasticity of stem cells in response to environmental change is critical for multicellular organisms.Here,we show that MYB3R-like directly activates the key plant stem-cell regulator WUSCHEL(WUS)by recruiting the methyltransferase ROOT INITIATION DEFECTIVE 2(RID2),which functions in m7G methylation of the 5′cap of WUS mRNA to protect it from degradation.Transcriptomic and molecular analyses showed that protein-folding genes are repressed by WUS to maintain precise protein synthesis in stem cells by preventing the reuse of misfolded proteins.Interestingly,we found that upon heat stress,the MYB3R-like/RID2 module is repressed to reduce WUS transcript abundance through decapping of nascent WUS mRNA.This releases the inhibition of protein-folding capacity in stem cells and protects them from heat shock by eliminating misfolded protein aggregation.Taken together,our results reveal a strategic trade-off whereby plants reduce the accuracy of protein synthesis in exchange for the survival of stem cells at high temperatures.

Brassinosteroids Regulate Root Growth, Development, and Symbiosis

Brassinosteroids （BRs） are natural plant hormones critical for growth and development. BR-deficient or signaling mutants show significantly shortened root phenotypes. But for a long time, it was thought that these phenotypes were solely caused by reduced root cell elongation in the mutants. Functions of BRs in regulating root development have been largely neglected. Recent detailed analyses, however, revealed that BRs are not only involved in root cell elongation but are also involved in many aspects of root development, such as maintenance of meristem size, root hair formation, lateral root initiation, gravitropic response, mycorrhiza formation, and nodulation in legume species. In this review, current findings on the functions of BRs in mediating root growth, development, and symbiosis are discussed.

BAK1 Directly Regulates Brassinosteroid Perception and BRI1 Activation

Plants utilize plasma membrane-localized receptor-like kinases （RLKs） to sense extracellular signals to coordinate growth, development, and innate immune responses. BAK1 regulates multiple signaling pathways acting as a co-receptor of several distinct ligand-binding RLKs. It has been debated whether BAK1 serves as an essential regulatory component or only a signal amplifier without pathway specificity. This issue has been clarified recently. Genetic and structural analyses indicated that BAK1 and its homologs play indispensible roles in mediating brassinosteroid （BR） signaling pathway by directly perceiving the ligand BR and activating the receptor of BR, BRII. The mechanism revealed by these studies now serves as a paradigm for how a pair of RLKs can function together in ligand binding and subsequent initiation of signaling.

Genome-Wide Expression Pattern Analyses of the Arabidopsis Leucine-Rich Repeat Receptor-Like Kinases

Receptor-like protein kinases （RLKs） are a large group of transmembrane proteins playing critical roles in cell-cell and cell--environment communications. Based on extracellular domain structures, RLKs were classified into more than 21 subfamilies, among which leucine-rich repeat RLKs （LRR-RLKs） belong to the largest subfamily in plants such as Arabidopsis and rice. In Arabidopsis, there are approximately 223 LRR-RLKs, but only about 60 of which have been functionally described to date. To systematically investigate the roles of LRR-RLKs in regulating plant growth, development, and stress adaptations, we generated promoter：：GUS transgenic plants for all 223 LRR-RLK genes in Arabidopsis and analyzed their detailed expression patterns at various developmental stages. The results provide valuable resources for functionally elucidating this large and essential signaling protein subfamily.