Mechanism of floral scent production in Osmanthus fragrans and the production and regulation of its key floral constituents,β-ionone and linalool

Sweet osmanthus(Osmanthus fragrans Lour.)is among the top ten most well-known flowers in China and is recognized as both an aromatic plant and ornamental flower.Here,manual sectioning,scanning electron microscopy,and transmission electron microscopy of sweet osmanthus petals revealed that large amounts of lipids are present inside the petal cells and on the cell surfaces.However,no secretory structures were observed.Instead,the petal cells protrude slightly outward,and the surfaces of the cells are adorned with highly regular brush-shaped hairs.The surfaces of the‘Yingui’petals possessed mostly curled and more numerous hairs,whereas the‘Dangui’petals possessed fewer brush-shaped and more sparsely arranged hairs.In addition,many granular substances were attached to the brush-shaped hairs,and the granules were denser on the hairs of the‘Yingui’petals compared to the hairs on the‘Dangui’petals.Furthermore,35 aromatic components in the‘Yingui’petals and 30 aromatic components in the‘Dangui’petals were detected via GC-MS.The main aromatic component of the‘Yingui’petals wasβ-ionone,whereas that of the‘Dangui’petals was linalool and its oxides.Transcriptome sequencing and qRT-PCR indicated that the highβ-ionone content in the‘Yingui’petals was due to the overexpression of CCD1 and CCD4 and that the high linalool content in the‘Dangui’petals was due to the overexpression of MECS,HDR,IDI1,and LIS1,which function upstream of the linalool synthetic pathway.In particular,the expression levels of CCD4 and LIS1 were upregulated by 5.5-and 5.1-fold in the‘Yingui’and‘Dangui’petals,respectively.One transcription factor(ERF61)was cloned and named,and the expression pattern of ERF61 in sweet osmanthus petals was found to be generally consistent with that of CCD4.Tobacco transformation experiments,yeast one-hybrid experiments,and electrophoretic mobility shift assays indicated that ERF61 binds to the CCD4 promoter and stimulates CCD4 expression,thereby regulating the synthesis ofβ-ionone in sweet osmanthus petals.

Phylogenomics and integrative taxonomy reveal two new species of Amana(Liliaceae)

Until now the genus Amana(Liliaceae),known as ’East Asian tulips’,has contained just seven species.In this study,a phylogenomic and integrative taxonomic approach was used to reveal two new species,Amana nanyueensis from Central China and A.tianmuensis from East China.A.nanyueensis resembles Amana edulis in possessing a densely villous-woolly bulb tunic and two opposite bracts,but differs in its leaves and anthers.Amana tianmuensis resembles Amana erythronioides in possessing three verticillate bracts and yellow anthers,but differs in aspects of its leaves and bulbs.These four species are clearly separated from each other in principal components analysis based on morphology.Phylogenomic analyses based on plastid CDS further support the species delimitation of A.nanyueensis and A.tianmuensis and suggests they are closely related to A.edulis.Cytological analysis shows that A.nanyueensis and A tianmuensis are both diploid(2n=2x=24),different from A edulis,which is either diploid(northern populations) or tetraploid(southern populations,2n=4x=48).The pollen morphology of A.nanyueensis is similar to other Amana species(single-groove germination aperture),but A.tianmuensis is quite different because of the presence of a sulcus membrane,which creates the illusion of double grooves.Ecological niche modelling also revealed a niche differentiation between A.edulis,A.nanyueensis and A.tianmuensis.

Warming decreases photosynthates and yield of soybean [Glycine max(L.) Merrill] in the North China Plain

Understanding the responses of field crops such as soybean to climate warming is critical for economic development and adaptive management of food security. A field warming experiment was conducted using infrared heaters to investigate the responses of soybean phenology, photosynthetic characteristics, and yield to climate warming in the North China Plain. The results showed that 0.4 °C and 0.7 °C increases in soybean canopy air and soil temperature advanced anthesis stage by 3.8 days and shortened the length of entire growth stage by 4.5 days. Warming also decreased the leaf photosynthetic rate by 6.6% and 10.3% at the anthesis and seed filling stages, respectively, but increased the leaf vapor pressure deficit by 9.4%, 15.7%, and 14.1% at the anthesis, pod setting, and seed filling stages,respectively. However, leaf soluble sugar and starch were decreased by 25.6% and 20.5%,respectively, whereas stem soluble sugar was reduced by 12.2% at the anthesis stage under experimental warming. The transportation amount of leaf soluble sugar and contribution rate of transportation amount to seed weight were reduced by 58.2% and 7.7%, respectively,under warming. As a result, warming significantly decreased 100-seed weight and soybean yield by 20.8% and 45.0%, respectively. Our findings provide better mechanistic understanding of soybean yield response to climate warming and could be helpful for forecasting soybean yield under future climate warming conditions.

Positive adaptation of Salix eriostachya to warming in the treeline ecotone,East Tibetan Plateau

Understanding of treeline ecotone ecophysiological adaptation to climate warming is still very limited. Furthermore, it is difficult to predict which plant species could dominate in the future. For this reason, a study was conducted in the treeline ecotone, East Tibetan Plateau to detect the adaptation of the dwarf willow(Salix eriostachya) to experimental warming. Compared to ambient conditions, the experimental warming advanced the bud break by 12 days, delayed the leaf abscission by20 days, and prolonged the growing period by 28 days.It also increased photosynthesis(47%), number of leaves(333%), leaf area(310%), and carbon sequestration of the dwarf willow. Experimental warming did not affect carbon use efficiency, but decreased water use efficiency significantly.Experimental warming enhanced the clonal ramets of Salix eriostachya(+ 3.7 shrubs m-2). The frequent air temperature fluctuations had minor effect on Salix eriostachya. Based on these findings, we highlighted that Salix eriostachya could dominate in the community treeline ecotone of east Tibetan Plateau in the future climate warming scenario.

Development of genomic resources for the genus Celtis (Cannabaceae) based on genome skimming data

Celtis is a Cannabaceae genus of 60e70 species of trees,or rarely shrubs,commonly known as hackberries.This woody genus consists of very valuable forest plants that provide important wildlife habitat for birds and mammals.Although previous studies have identified its phylogenetic position,interspecific relationships within Celtis remain unclear.In this study,we generated genome skimming data from five Celtis species to analyze phylogenetic relationships within the genus and develop genome resources.The plastomes of Celtis ranged in length from 158,989 bp to 159,082 bp,with a typical angiosperm quadripartite structure,and encoded a total of 132 genes with 20 duplicated in the IRs.Comparative analyses showed that plastome content and structure were relatively conserved.Whole plastomes showed no signs of gene loss,translocations,inversions,or genome rearrangement.Six plastid hotspot regions(trnH-psbA,psbA-trnK,trnG-trnR,psbC-trnS,cemA-petA and rps8-rpl14),4097 polymorphic nuclear SSRs,as well as 62 low or single-copy gene fragments were identified within Celtis.Moreover,the phylogenetic relationships based on the complete plastome sequences strongly endorse the placement of C.biondii as sister to the((((C.koraiensis,C.sinensis),C.tetrandra),C.julianae),C.cerasifera)clade.These findings and the genetic resources developed here will be conducive to further studies on the genus Celtis involving phylogeny,population genetics,and conservation biology.

Evolution and roles of cytokinin genes in angiosperms 2:Do ancient CKXs play housekeeping roles while non-ancient CKXs play regulatory roles?

Cytokinin oxidase/dehydrogenase(CKX)is a key enzyme responsible for the degradation of endogenous cytokinins.However,the origins and roles of CKX genes in angiosperm evolution remain unclear.Based on comprehensive bioinformatic and transgenic plant analyses,we demonstrate that the CKXs of land plants most likely originated from an ancient chlamydial endosymbiont during primary endosymbiosis.We refer to the CKXs retaining evolutionarily ancient characteristics as“ancient CKXs”and those that have expanded and functionally diverged in angiosperms as“non-ancient CKXs”.We show that the expression of some non-ancient CKXs is rapidly inducible within 15 min upon the dehydration of Arabidopsis,while the ancient CKX(AtCKX7)is not drought responsive.Tobacco plants overexpressing a non-ancient CKX display improved oxidative and drought tolerance and root growth.Previous mutant studies have shown that non-ancient CKXs regulate organ development,particularly that of flowers.Furthermore,ancient CKXs preferentially degrade cis-zeatin(cZ)-type cytokinins,while non-ancient CKXs preferentially target N6-(Δ2-isopentenyl)adenines(iPs)and trans-zeatins(tZs).Based on the results of this work,an accompanying study(Wang et al.https://doi.org/10.1038/s41438-019-0211-x)and previous studies,we hypothesize that non-ancient CKXs and their preferred substrates of iP/tZ-type cytokinins regulate angiosperm organ development and environmental stress responses,while ancient CKXs and their preferred substrates of cZs play a housekeeping role,which echoes the conclusions and hypothesis described in the accompanying report(Wang,X.et al.Evolution and roles of cytokinin genes in angiosperms 1:Doancient IPTs play housekeeping while non-ancient IPTs play regulatory roles?Hortic Res 7,(2020).https://doi.org/10.1038/s41438-019-0211-x).

Egg tanning improves the efficiency of CRISPR/Cas9-mediated mutant locust production by enhancing defense ability after microinjection

The mutant efficiency and hatching ratio are two key factors that significantly affect the construction of genome-modified mutant insects.In the construction of CRISPR/Cas9-mediated dsLmRNase2^(–/–)mutant locusts,we found that the tanned eggs which experienced a 20-min contact with the oocyst exhibited a higher success rate compared to fresh newly-laid eggs that were less tanned.However,the heritable efficiency of the dsLmRNase2 deletion to the next generation G_(1 )progeny was similar between adults derived from the tanned or less tanned engineered eggs.Further,the similar effective mutant ratios in the normally developed eggs and G_(0) adults of tanned and less tanned eggs also indicated that tanning did not reduce the absolute mutation efficiency induced by CRISPR/Cas9.Moreover,we found that the syncytial division period,which was longer than the time for tanning,conferred a window period for microinjection treatment with efficient mutation in both tanned and less tanned eggs.We further found that tanned eggs exhibited a higher hatching rate due to a reduced infection rate following microinjection.Both the anti-pressure and ultrastructure analyses indicated that the tanned eggs contained compressed eggshells to withstand increased external pressure.In summary,tanned eggs possess stronger defense responses and higher efficiency of genome editing,providing an improved model for developing Cas9-mediated gene editing procedures in locusts.

Genome-wide identification and expression analysis of the GhIQD gene family in upland cotton(Gossypium hirsutum L.)

Background:Calmodulin(CaM)is one of the most important Ca^(2+)signaling receptors because it regulates diverse physiological and biochemical reactions in plants.CaM functions by interacting with CaM-binding proteins(CaMBPs)to modulate Ca^(2+)signaling.IQ domain(IQD)proteins are plant-specific CaMBPs that bind to CaM by their specific CaM binding sites.Results:In this study,we identified 102 GhIQD genes in the Gossypium hirsutum L.genome.The GhIQD gene family was classified into four clusters(Ⅰ,Ⅱ,Ⅲ,andⅣ),and we then mapped the GhIQD genes to the G.hirsutum L.chromosomes.Moreover,we found that 100 of the 102 GhIQD genes resulted from segmental duplication events,indicating that segmental duplication is the main force driving GhIQD gene expansion.Gene expression pattern analysis showed that a total of 89 GhIQD genes expressed in the elongation stage and second cell wall biosynthesis stage of the fiber cells,suggesting that GhIQD genes may contribute to fiber cell development in cotton.In addition,we found that 20 selected GhIQD genes were highly expressed in various tissues.Exogenous application of MeJA significantly enhanced the expression levels of GhIQD genes.Conclusions:Our study shows that GhIQD genes are involved in fiber cell development in cotton and are also widely induced by MeJA.Thw results provide bases to systematically characterize the evolution and biological functions of GhIQD genes,as well as clues to breed better cotton varieties in the future.

Spatiotemporal variations in the growth status of declining wild apple trees in a narrow valley in the western Tianshan Mountains, China

Malus sieversii(wild apple tree),only distributed in the Tianshan Mountains in Central Asia,is a tertiary relic species and an ancestral species of cultivated apples.However,existing natural populations of wild apple trees have been declining.To date,spatiotemporal variations in the growth status of declining wild apple trees and influencing factors in the narrow valley areas in the Tianshan Mountains remain unclear.In this study,field investigation and sampling were carried out in three years(2016-2018)at four elevations(1300,1400,1500,and 1600 m)in the Qiaolakesai Valley(a typical longitudinal narrow valley in the Yili River Valley)of the western Tianshan Mountains in Xinyuan County,Xinjiang Uygur Autonomous Region,China.Projective coverage,dead branch percentage,and 18 twig traits(these 20 parameters were collectively referred to as plant traits)were determined to comprehensively reflect the growth status of declining wild apple trees.The values of dead branch percentage ranged from 36%to 59%,with a mean of 40%.Year generally showed higher impact on plant traits than elevation.In 2017 and 2018,projective coverage,leaf size,leaf nitrogen concentration,and nitrogen to phosphorous ratio were markedly higher than those in 2016.However,dead branch percentage and leaf and stem phosphorous concentrations showed the opposite trend.Most of the topological parameters of plant trait networks differed in the three years,but the strength of trait-trait association increased year by year.The mean difference between day and night temperatures(MDT),annual accumulative precipitation,soil electrical conductivity,and soil pH had the greatest impact on the plant trait matrix.The growth status of declining wild apple trees was directly and positively affected by MDT and leaf size.In conclusion,the growth of declining wild apple trees distributed in the narrow valley areas was more sensitive to interannual environmental changes than elevation changes.The results are of great significance for further revealing the decline mechanism of wild apple trees in the Tianshan Mountains.

Dynamics of 18 (<i>Sophora japonica</i>) Tree Community’s Crown Volume along Elevation Gradient in <i>Ye County</i>

Applying plant community diversity techniques and SPSS statistic analysis, we quantified the relationship between crown volume of 18 (Sophora japonica) tree communities and elevation along different elevation gradient in Ye County in the study. We concluded that there was a significantly positive correlation between crown volume of 18 (Sophora japonica) tree communities and elevation gradient (P Sophora japonica) tree communities increased along elevation from 50 m to 200 m in Ye County in 2018. Therefore, understanding dynamic connecting crown volume of 18 (Sophora japonica) communities and elevation can be not just applied to preserve of (Sophora japonica) tree communities, but also applied to sustainable of biodiversity and processes of tree community’s crown volume along elevation.

Genetic map construction and functional characterization of genes within the segregation distortion regions(SDRs)in the F_(2:3) populations derived from wild cotton species of the D genome

Background:Segregation distortion(SD)is a common phenomenon among stable or segregating populations,and the principle behind it still puzzles many researchers.The F2:3 progenies developed from the wild cotton species of the D genomes were used to investigate the possible plant transcription factors within the segregation distortion regions(SDRs).A consensus map was developed between two maps from the four D genomes,map A derived from F2:3 progenies of Gossypium klotzschianum and G.davidsonii while Map B from G.thurberi and G.trilobum F2:3 generations.In each map,188 individual plants were used.Results:The consensus linkage map had 1492 markers across the 13 linkage groups with a map size of 1467.445 cM and an average marker distance of 1.0370 cM.Chromosome D502 had the highest percentage of SD with 58.6%,followed by Chromosome D507 with 47.9%.Six thousand and thirty-eight genes were mined within the SDRs on chromosome D502 and D507 of the consensus map.Within chromosome D502 and D507,2308 and 3730 genes were mined,respectively,and were found to belong to 1117 gourp out of which 622 groups were common across the two chromosomes.Moreover,genes within the top 9 groups related to plant resistance genes(R genes),whereas 188 genes encoding protein kinase domain(PF00069)comprised the largest group.Further analysis of the dominant gene group revealed that 287 miRNAs were found to target various genes,such as the gra-miR398,gramiR5207,miR164a,miR164b,miR164c among others,which have been found to target top-ranked stress-responsive transcription factors such as NAC genes.Moreover,some of the stress-responsive cis-regulatory elements were also detected.Furthermore,RNA profiling of the genes from the dominant family showed that higher numbers of genes were highly upregulated under salt and osmotic stress conditions,and also they were highly expressed at different stages of fiber development.Conclusion:The results indicated the critical role of the SDRs in the evolution of the key regulatory genes in plants.

Case study of a rhizosphere microbiome assay on a bamboo rhizome with excessive shoots

Young moso bamboo shoots are a popular seasonal food and an important source of income for farmers,with value for cultivation estimated at$30,000 per hectare.Bamboo also has great environmental importance and its unique physiology is of scientific interest.A rare and valuable phenomenon has recently appeared where a large number of adjacent buds within a single moso bamboo rhizome have grown into shoots.Although of practical importance for the production of edible shoots,such occurrences have not been scientifically studied,due to their rarity.Analysis of collected reports from enhanced shoot production events in China showed no evidence that enhanced shoot development was heritable.We report the analysis of the rhizosphere microbiome from a rhizome with 18 shoots,compared to rhizomes having one or no shoots as controls.The community of prokaryotes,but not fungi,correlated with the shoot number.Burkholderia was the most abundant genus,which was negatively correlated with rhizome shoot number,while Clostridia and Ktedonobacteria were positively correlated.Two Burkholderia strains were isolated and their plant-growth promoting activity was tested.The isolated Burkholderia strains attenuated the growth of bamboo seedlings.These data provide the first study on excessive shoot development in bamboo,which will facilitate hypothesis building for future studies.

Genome-wide association study identifies novel candidate loci or genes affecting stalk strength in maize

Stalk strength increases resistance to stalk lodging,which causes maize(Zea mays L.)production losses worldwide.The genetic mechanisms regulating stalk strength remain unclear.In this study,three stalk strength-related traits(rind penetrometer resistance,stalk crushing strength,and stalk bending strength)and four plant architecture traits(plant height,ear height,stem diameter,stem length)were measured in three field trials.Substantial phenotypic variation was detected for these traits.A genome-wide association study(GWAS)was conducted using general and mixed linear models and 372,331 single-nucleotide polymorphisms(SNPs).A total of 94 quantitative trait loci including 241 SNPs were detected.By combining the GWAS data with public gene expression data,56 candidate genes within 50 kb of the significant SNPs were identified,including genes encoding flavonol synthase(GRMZM2G069298,ZmFLS2),nitrate reductase(GRMZM5G878558,ZmNR2),glucose-1-phosphate adenylyltransferase(GRMZM2G027955),and laccase(GRMZM2G447271).Resequencing GRMZM2G069298 and GRMZM5G878558 in all tested lines revealed respectively 47 and 2 variants associated with RPR.Comparison of the RPR of the zmnr2EMS mutant and the wild-type plant under high-and low-nitrogen conditions verified the GRMZM5G878558 function.These findings may be useful for clarifying the genetic basis of stalk strength.The identified candidate genes and variants may be useful for the genetic improvement of maize lodging resistance.

Comparative transcriptome and lipidome reveal that a low K^(+) signal effectively alleviates the effect induced by Ca^(2+) deficiency in cotton fibers

Calcium(Ca^(2+))plays an important role in determining plant growth and development because it maintains cell wall and membrane integrity.Therefore,understanding the role of Ca^(2+)in carbon and lipid metabolism could provide insights into the dynamic changes in cell membranes and cell walls during the rapid elongation of cotton fibers.In the present study,we found that the lack of Ca^(2+)promoted fiber elongation and rapid ovule expansion,but it also caused tissue browning in the ovule culture system.RNA-sequencing revealed that Ca^(2+)deficiency induced cells to be highly oxidized,and the expression of genes related to carbon metabolism and lipid metabolism was activated significantly.All gene members of nine key enzymes involved in glycolysis were up-regulated,and glucose was significantly reduced in Ca^(2+)deficiency-treated tissues.Ca^(2+)deficiency adjusted the flowing of glycolysis metabolic.However,low K^(+)recovered the expression levels of glycolysis genes and glucose content caused by Ca^(2+)deficiency.Electrospray ionizationtandem mass spectrometry technology was applied to uncover the dynamic profile of lipidome under Ca^(2+)and K^(+)interacted conditions.Ca^(2+)deficiency led to the decrease of fatty acid(FA),diacylglycerol(DAG),glycolipid and the significant increase of triacylglycerol(TAG),phospholipid phosphatidylethanolamine(PE),phosphatidylglycerol(PG),and PC(phosphatidylcholine).Low K^(+)restored the contents of FA,phospholipids,and glycolipids,effectively relieved the symptoms caused by Ca^(2+)deficiency,and recovered the development of fiber cells.This study revealed dynamic changes in transcript and metabolic levels and uncovered the signaling interaction of Ca^(2+)deficiency and low K^(+)in glycolysis and lipid metabolism during fiber development.

Community structure and carbon metabolism functions of bacterioplankton in the Guangdong coastal zone

Coastal ecosystems are an important region for biogeochemical cycling,are a hotspot of anthropogenic disturbance and play a crucial role in global carbon cycling through the metabolic activities of bacterioplankton.Bacterioplankton can be broadly classified into two lifestyles:free-living(FL)and particle-attached(PA).However,how coastal bacterioplankton the community structure,co-occurrence networks and carbon metabolic functions with different lifestyles are differentiated is still largely unknown.Understanding these processes is necessary to better determine the contributions of coastal bacterioplankton to carbon cycling.Here,the characteristics of community structure and carbon metabolism function of bacterioplankton with two lifestyles in the coastal areas of Guangdong Province were investigated using amplicon sequencing,metagenomic,and metatranscriptomic techniques.The results show that the main bacterioplankton responsible for carbon metabolism were the Pseudomonadota,Bacteroidota,and Actinomycetota.The microbial community structure,carbon metabolic function,and environmental preferences differ between different lifestyles.FL and PA bacteria exhibited higher carbon fixation and degradation potentials,respectively.A range of environmental factors,such as dissolved oxygen,pH,and temperature,were associated with the community structure and carbon metabolic functions of the bacterioplankton.Human activities,such as nutrient discharge,may affect the distribution of functional genes and enhance the carbon degradation functions of bacterioplankton.In conclusion,this study increased the understanding of the role of microorganisms in regulating carbon export in coastal ecosystems with intense human activity.

Global patterns of the responses of leaf-level photosynthesis and respiration in terrestrial plants to experimental warming

Aims The balance between leaf photosynthesis and respiration of terrestrial plants determines the net carbon(C)gain by vegetation and consequently is important to climate–C cycle feedback.This study is to reveal the global patterns of the responses of leaf-level net photosynthesis and dark respiration to elevated temperature.Methods Data for leaf-level net photosynthesis rate(P_(n))and dark respiration rate(R_(d))in natural terrestrial plant species with standard deviation(or standard error or confidence interval)and sample size were collected from searched literatures on Web of Science.Then a metaanalysis was conducted to estimate the effects of experimental warming on leaf-level P_(n) and R_(d) of terrestrial plants.Important findings Across all the plants included in the analysis,warming enhanced P_(n) and R_(d) significantly by 6.13 and 33.14%,respectively.However,the responses were plant functional type(PFT)specific.Specifically,photosynthesis of C_(4) herbs responded to experimental warming positively but that of C_(3) herbs did not,whereas their respiratory responses were similar,suggesting C_(4) plants would benefit more from warming.The photosynthetic response declined linearly with increasing ambient temperature.The respiratory responses linearly enhanced with the increase in warming magnitude.In addition,a thermal acclimation of R_(d),instead of P_(n),was observed.Although greater proportion of fixed C was consumed(greater R_(d)/P_(n) ratio),warming significantly enhanced the daily net C balance at the leaf level.This provides an important mechanism for the positive responses of plant biomass and net primary productivity to warming.Overall,the findings,including the contrastive responses of different PFTs and the enhancement in daily leaf net C balance,are important for improving model projection of the climate–C cycle feedback.

Interactive effects of understory removal and fertilization on soil respiration in subtropical Eucalyptus plantations

Aims It has been well recognized that understory vegetation plays an important role in driving forest ecosystem processes and functioning.In subtropical plantation forests,understory removal and fertiliza-tion have been widely applied;however,our understanding on how understory removal affects soil respiration and how the process is regulated by fertilization is limited.Here,we conducted an under-story removal experiment combined with fertilization to evaluate the effects of the two forest management practices and their inter-actions on soil respiration in subtropical forest in southern China.Methods The study was conducted in a split-plot design with fertilization as the whole-plot factor,understory removal as the subplot factor and block as the random factor in subtropical Eucalyptus plantations.In total,there were four treatments:control with unfertilized and intact understory(CK),understory removal but without fertilization(UR),with fertilization but without understory removal(FT)and with fertilization+understory removal(FT+UR).Eucalyptus above-and belowground biomass increment,fine root biomass,soil tempera-ture,soil moisture and soil respiration were measured in the present study.understory respiration(Ru)was quantified in different ways:Ru=RCK−Ru or Ru=RFT−R(FT+u);fertilization increased soil respiration(RFI)was also quantified in different ways:RFI=RFT−RCK or RFI=R(FT+u)−Ru.Important Findingsover a 2-year experiment,our data indicate that understory removal significantly decreased soil respiration,while fertilization increased soil respiration.understory removal decreased soil respiration by 28.8%under fertilization,but only 15.2%without fertilization.Fertilization significantly increased soil respiration by 23.6%with the presence of understory vegetation,and only increased by 3.7%when understory was removed,indicating that fertilization increased soil respiration mainly by increasing the contribution of the understory.our study advances our understanding of the interactive effects of understory management and fertilization on soil respiration in subtropical plantations.

A Resource for Inactivation of MicroRNAs Using Short Tandem Target Mimic Technology in Model and Crop Plants

microRNAs (miRNAs)are endogenous small non-coding RNAs that bind to mRNAs and target them for cleavage and/or translational repression,leading to gene silencing.We previously developed short tandem target mimic (STTM)technology to deactivate endogenous miRNAs in Arabidopsis.Here,we created hundreds of STTMs that target both conserved and species-specific miRNAs in Arabidopsis,tomato,rice,and maize,providing a resource for the functional interrogation of miRNAs.We not only revealed the functions of several miRNAs in plant development,but also demonstrated that tissue-specific inactivation of a few miRNAs in rice leads to an increase in grain size without adversely affecting overall plant growth and development.RNA-seq and small RNAseq analyses of STTM156/157 and STTM165/166 transgenic plants revealed the roles of these miRNAs in plant hormone biosynthesis and activation,secondary metabolism,and ion-channel activity-associated electrophysiology,demonstrating that STTM technology is an effective approach for studying miRNA functions.To facilitate the study and application of STTM transgenic plants and to provide a useful platform for storing and sharing of information about miRNA-regulated gene networks,we have established an online Genome Browser (https://blossom.ffr.mtu.edu/designindex2.php) to display the transcriptomic and miRNAomic changes in STTMinduced miRNA knockdown plants.

Video Scene Invariant Crowd Density Estimation Using Geographic Information Systems

Crowd density is an important factor of crowd stability.Previous crowd density estimation methods are highly dependent on the specific video scene.This paper presented a video scene invariant crowd density estimation method using Geographic Information Systems(GIS) to monitor crowd size for large areas.The proposed method mapped crowd images to GIS.Then we can estimate crowd density for each camera in GIS using an estimation model obtained by one camera.Test results show that one model obtained by one camera in GIS can be adaptively applied to other cameras in outdoor video scenes.A real-time monitoring system for crowd size in large areas based on scene invariant model has been successfully used in 'Jiangsu Qinhuai Lantern Festival,2012'.It can provide early warning information and scientific basis for safety and security decision making.

Osmotically stress-regulated the expression of glutathione peroxidase 3 in Arabidopsis

Gene expression of glutathione peroxidase 3 (ATGPX3) in response to osmotic stress was analyzed in Arabidopsis using ATGPX3 promoter-glucuronidase (GUS) transgenic plants. High levels of GUS ex- pression were detected under osmotic stress in ATGPX3 promoter-GUS transgenic plants. Compared with the wild type, the growth and development of ATGPX3 mutants (atgpx3-1) were more sensitive to mannitol. In addition, the expression of RD29A, ABI1, ABI2 and RbohD in atgpx3-1 was induced by ABA stress. These results suggest that ATGPX3 might be involved in the signal transduction of osmotic stress.