Multi-genome evolutionary study of the ABC1 gene family and identification of the pleiotropic effects of OsABC1-13 in rice development

In four rice genomes,85 ABC1-family genes were identified by comparative genomics,evolution,genetics,and physiology.One,OsABC1-13,was shown by knockdown and knockout experiments to affect plant height,grain size,and photosynthetic capability.

聚氨酯弹性体分子结构对阻尼及力学性能的影响

为获得深水环境用减振降噪聚氨酯弹性体(PUE),选择甲苯二异氰酸酯(TDI)、聚丙二醇2000(PPG2000)和三乙醇胺(TEA)为原材料浇注制备了PUE,探究硬段含量、R值和合成方法对PUE阻尼性能和压缩模量的影响。结果表明:随着硬段含量的增加,PUE的tanδ峰值减小,压缩模量增强;随着R值的增加,Tg增大,压缩模量先增大后降低,R=2时达到峰值。预聚体法和一步法对合成出PUE的tanδ的影响较小,但预聚体法合成PUE的压缩模量明显优于一步法。增加分子链刚度、氢键化程度和硬段微区分布均匀程度可以有效提升PUE的压缩模量,但会导致阻尼性能下降。

Application of a novel backwashing process in upflow biological aerated filter

To improve the efficiency of backwashing in upflow biological aerated filter （BAF）, a novel backwashing process named air-water siphon backwashing （AWSB） was proposed and applied on laboratory scale. The effects of backwashing on turbidity and suspended solid （SS） in backwashing efluent using this new backwashing process were compared with those of traditional backwashing process, namely air-water backwashing （AWB）. In AWB, the turbidity of backwashing efluent maintained 100 NUT when consumed 60 min and 10.5 L water. However, in AWSB, it declined to 44 NUT, consumed 40 min, and 7 L water. The COD removal of BAF after backwashing was also analyzed. The average removal rate of COD in the reactor backwashed by AWB and AWSB was 89.34% and 90.91%, respectively. Compared with AWB, the backwashing interval had been prolonged 35%. The volume of backwashing water in that AWSB was only 66.7% of that in AWB. The results demonstrated that AWSB required less water and took shorter backwashing timerelative to AWB to achieve the same turbidity of backwashing efluent, and AWSB was more effective in removing fouling than that of AWB. More significant advantage of AWSB was that the backwashing interval was effectively prolonged

Introduction to the Special Issue on Mechanics of Composite Materials and Structures

Plate,shell and panel are basic structures used in engineering and industry.These structures play an important role as main supporting component in all kinds of structures in machinery,civil engineering,ship building,flight vehicle manufacturing,etc.Composite materials and structures are widely used in aerospace,marine,automobile industries due to their designable characteristic,lightweight advantageous,high specific strength and stiffness.Common configurations include laminated materials,hybrid layered materials,sandwich core materials and structures(foam,honeycomb,corrugated and lattice cores,etc.).How to establish an accurate analytical and numerical model is one of the most important subjects in composite materials and structures.The topics discussed in this special issue include aspects of core-face bonding and reinforcement,enhancement of core mechanical properties and panel performance(including the role of structural hierarchy),and multifunctional advantages offered by different core constructions.In addition,the special issue discusses potential applications,including in morphing wing design,impact resistance and ultralightweight applications.Future research directions are discussed.

Post-transcriptional regulation of grain weight and shape by the RBP-A-J-K complex in rice

RNA-binding proteins(RBPs)are components of the post-transcriptional regulatory system,but their regulatory effects on complex traits remain unknown.Using an integrated strategy involving map-based cloning,functional characterizations,and transcriptomic and population genomic analyses,we revealed that RBP-K(LOC_Os08g23120),RBP-A(LOC_Os11g41890),and RBP-J(LOC_Os10g33230)encode proteins that form an RBP-A-J-K complex that negatively regulates rice yield-related traits.Examinations of the RBP-A-J-K complex indicated RBP-K functions as a relatively non-specific RBP chaperone that enables RBP-A and RBP-J to function normally.Additionally,RBP-J most likely affects GA pathways,resulting in considerable increases in grain and panicle lengths,but decreases in grain width and thickness.In contrast,RBP-A negatively regulates the expression of genes most likely involved in auxin-regulated pathways controlling cell wall elongation and carbohydrate transport,with substantial effects on the rice grain filling process as well as grain length and weight.Evolutionarily,RBP-K is relatively ancient and highly conserved,whereas RBP-J and RBP-A are more diverse.Thus,the RBP-A-J-K complex may represent a typical functional model for many RBPs and protein complexes that function at transcriptional and post-transcriptional levels in plants and animals for increased functional consistency,efficiency,and versatility,as well as increased evolutionary potential.Our results clearly demonstrate the importance of RBP-mediated post-transcriptional regulation for the diversity of complex traits.Furthermore,rice grain yield and quality may be enhanced by introducing various complete or partial loss-of-function mutations to specific RBP genes using clustered regularly interspaced palindromic repeats(CRISPR)/CRISPR-associated protein 9 technology and by exploiting desirable natural tri-genic allelic combinations at the loci encoding the components of the RBP-A-J-K complex through marker-assisted selection.

Auxin signaling module OsSK41-OsIAA10-OsARF regulates grain yield traits in rice

Auxin is an important phytohormone in plants, and auxin signaling pathways in rice play key roles in regulating its growth, development, and productivity. To investigate how rice grain yield traits are regulated by auxin signaling pathways and to facilitate their application in rice improvement, we validated the functional relationships among regulatory genes such as OsIAA10, OsSK41, and OsARF21 that are involved in one of the auxin(OsIAA10) signaling pathways. We assessed the phenotypic effects of these genes on several grain yield traits across two environments using knockout and/or overexpression transgenic lines.Based on the results, we constructed a model that showed how grain yield traits were regulated by OsIAA10 and OsTIR1, OsAFB2, and OsSK41 and OsmiR393 in the OsSK41-OsIAA10-OsARF module and by OsARF21 in the transcriptional regulation of downstream auxin response genes in the OsSK41-OsIAA10-OsARF module. The population genomic analyses revealed rich genetic diversity and the presence of major functional alleles at most of these loci in rice populations. The strong differentiation of many major alleles between Xian/indica and Geng/japonica subspecies and/or among modern varieties and landraces suggested that they contributed to improved productivity during evolution and breeding. We identified several important aspects associated with the genetic and molecular bases of rice grain and yield traits that were regulated by auxin signaling pathways.We also suggested rice auxin response factor(OsARF) activators as candidate target genes for improving specific target traits by overexpression and/or editing subspecies-specific alleles and by searching and pyramiding the ‘best' gene allelic combinations at multiple regulatory genes in auxin signaling pathways in rice breeding programs.

The kinase OsSK41/OsGSK5 negatively regulates amylose content in rice endosperm by affecting the interaction between OsEBP89 and OsBP5

Amylose content(AC) is the main factor determining the palatability, viscosity, transparency, and digestibility of rice(Oryza sativa)grains. AC in rice grains is mainly controlled by different alleles of the Waxy(Wx) gene. The AP2/EREBP transcription factor OsEBP89 interacts with the MYC-like protein OsBP5 to synergistically regulate the expression of Wx.Here, we determined that the GLYCOGEN SYNTHASE KINASE 5(OsGSK5, also named SHAGGY-like kinase 41 [OsSK41]) inhibits the transcriptional activation activity of OsEBP89 in rice grains during amylose biosynthesis. The loss of OsSK41 function enhanced Wx expression and increased AC in rice grains. By contrast, the loss of function of OsEBP89 reduced Wx expression and decreased AC in rice grains. OsSK41 interacts with OsEBP89 and phosphorylates four of its sites(Thr-28,Thr-30, Ser-238, and Thr-257), which makes OsEBP89 unstable and attenuates its interaction with OsBP5. Wx promoter activity was relatively weak when regulated by the phosphomimicvariantOsEBP89E–OsBP5but relatively strong when regulated by the nonphosphorylatable variant OsEBP89A–OsBP5.Therefore, OsSK41-mediated phosphorylation of OsEBP89 represents an additional layer of complexity in the regulation of amylose biosynthesis during rice grain development. In addition, our findings provide four possible sites for regulating rice grain AC via precise gene editing.

Design,fabrication,and dynamic mechanical responses of fiber-reinforced composite lattice materials

Fiber-reinforced composites are a popular lightweight materials used in a variety of engineering applications,such as aerospace,architecture,automotive,and marine construction,due to their attractive mechanical properties.Constructing lattice materials from fiber-reinforced composites is an efficient approach for developing ultra-lightweight structural systems with superior mechanical proper-ties and multifunctional benefits.In contrast to corrugated,foam,and honeycomb core materials,composite lattice materials can be manufactured with various architectural designs,such as woven,grid,and truss cores.Moreover,lattice materials with open-cell topology provide multifunctional advantages over conventional closed-cell honeycomb and foam structures and are thus highly desirable for developing aerospace systems,hypersonic vehicles,long-range rockets and missiles,ship and naval structures,and protective systems.The objective of this study is to review and analyze dynamic mechanical behavior performed by different researchers in the area of composite lattice materials and to highlight topics for future research.

A Novel QTL qTGW3 Encodes the GSK3/ SHAGGY-Like Kinase OsGSK5/OsSK41 that Interacts with OsARF4 to Negatively Regulate Grain Size and Weight in Rice

Grain size and shape are important determinants of grain weight and yield in rice. Here, we report a new major quantitative trait locus （QTL）, qTGW3, that controls grain size and weight in rice. This locus, qTGW3, encodes OsSK41 （also known as OsGSK5）, a member of the GLYCOGEN SYNTHASE KINASE 3/SHAGGY-like family. Rice near-isogenic lines carrying the loss-of-function allele of OsSK41 have increased grain length and weight. We demonstrate that OsSK41 interacts with and phosphorylates AUXIN RESPONSE FACTOR 4 （OsARF4）. Co-expression of OsSK41 with OsARF4 increases the accumulation of OsARF4 in rice protoplasts. Loss of function of OsARF4 results in larger rice grains. RNA-sequencing analysis suggests that OsARF4 and OsSK41 repress the expression of a common set of downstream genes, including some auxin-responsive genes, during rice grain development. The loss-of-function form of OsSK41 at qTGW3 represents a rare allele that has not been extensively utilized in rice breeding. Suppression of OsSK41 function by either targeted gene editing or QTL pyramiding enhances rice grain size and weight. Thus, our study reveals the important role of OsSK41 in rice grain development and provides new candidate genes for genetic improvement of grain yield in rice and perhaps in other cereal crops.

Additive and Over-dominant Effects Resulting from Epistatic Loci Are the Primary Genetic Basis of Heterosis in Rice

A set of 148 F9 recombinant inbred lines （RILs） was developed from the cross of an indica cultivar 93-11 and japonica cultivar DTI13, showing strong F1 heterosis. Subsequently, two backcross F1 （BCFI） populations were constructed by backcrossing these 148 RILs to two parents, 93-11 and DT713. These three related populations （281BCF1 lines, 148 RILs） were phenotyped for six yield-related traits in two locations. Significant inbreeding depression was detected in the population of RILS and a high level of heterosis was observed in the two BCF1 populations. A total of 42 main-effect quantitative trait loci （M-QTLs） and 109 epistatic effect QTL pairs （E-QTLs） were detected in the three related populations using the mixed model approach. By comparing the genetic effects of these QTLs detected in the RILs, BCF1 performance and mid-parental heterosis （HMp）, we found that, in both BCF1 populations, the QTLs detected could be classified into two predominant types： additive and over-dominant loci, which indicated that the additive and over-dominant effect were more important than complete or partially dominance for M-QTLs and E-QTLs. Further, we found that the E-QTLs detected collectively explained a larger portion of the total phenotypic variation than the M-QTLs in both RILs and BCF1 populations. All of these results suggest that additive and over-dominance resulting from epistatic loci might be the primary genetic basis of heterosis in rice.

Isolation and identification of genes expressed differentially in rice inflorescence meristem with suppression subtractive hybridization

A subtracted cDNA library of rice (Oryza sativa L.) inflorescence meristem (IM) was constructed using the suppression subtractive hybridization (SSH) method. The cDNAs of the rice shoot apical meristem (SAM) were used as 'driver' and inflorescence meristem (IM) as 'tester' in the experiment, respectively. Forty of 250 randomly chosen cDNA clones were identified by differential screening, which were IM-specific or IM-highly expressed. Most of the rice IM cDNAs cloned by SSH appear to represent rare transcripts, 40% of which were derived from truly differentially expressed genes. Of all the forty sequenced cDNA inserts, eleven contain the regions with 60%-90% identity to their homolog in GenBank, eighteen are expected to be new genes, only two correspond to published rice genes.

Cell concentration,viability and culture composition of airborne bacteria during a dust event in Beijing

Airborne bacteria were measured when a dust storm passed Beijing in spring 2012 with a focus on cell concentration, viability and TSA- and R2A-cultured strain composition. The concentration varied at an order of 10^7 cells/m3 with dust loading （demonstrated with PM10） and they had a very close correlation （RT2 = 0.91, p 〈 0.01）. At the time of highest PM10 of 652 μg/m3, the bacterial concentration reached 1.4 × 10^8 cells/m3, which was larger than that before and after the dust event by one order. Bacterial viability, the ratio of number concentration of viable cells to total cells, was 32%-64% and smaller in the dust plume than that before the dust arrival. Bacterial strains from the culture ranged between 2.5 × 10^4 and 4.6 × 10^5 CFU/m3 and no correlation with PM10 was determined. Their composition was different before and after the dust arrival according to 16S rRNA gene sequences and strains belong to Actinomycetes and Firmicutes were the majority in the dust samples.

The role of glutathione-mediated triacylglycerol synthesis in the response to ultra-high cadmium stress in Auxenochlorella protothecoides

Under ultra-high cadmium(Cd)stress,large amounts of glutathione are produced in Auxenochlorella protothecoides UTEX 2341,and the lipid content increases significantly.Glutathione is the best reductant that can effectively remove Cd,but the relationship between lipid accumulation and the cellular response to Cd stress has not been ascertained.Integrating analyses of the transcriptomes and lipidomes,the mechanism of lipid accumulation to Cd tolerance were studied from the perspectives of metabolism,transcriptional regulation and protein glutathionylation.Under Cd stress,basic metabolic pathways,such as purine metabolism,translation and pre-m RNA splicing process,were inhibited,while the lipid accumulation pathway was significantly activated.Further analysis revealed that the transcription factors(TFs)and genes related to lipid accumulation were also activated.Analysis of the TF interaction sites showed that ABI5,MYBrel and NF-YB could further regulate the expression of diacylglycerol acyltransferase through glutathionylation/deglutathionylation,which led to increase of the triacylglycerol(TAG)content.Lipidomes analysis showed that TAG could help maintain lipid homeostasis by adjusting its saturation/unsaturation levels.This study for the first time indicated that glutathione could activate TAG synthesis in microalga A.protothecoides,leading to TAG accumulation and glutathione accumulation under Cd stress.Therefore,the accumulation of TAG and glutathione can confer resistance to high Cd stress.This study provided insights into a new operation mode of TAG accumulation under heavy metal stress.

Systemic lupus erythematosus following human papillomavirus 9-valent vaccination

To the Editor:Systemic lupus erythematosus(SLE)is a chronic autoimmune disease of unknown cause that can affect any organ of the body.Human papillomavirus(HPV)infection is associated with the development of cervical dysplasia and cancer in SLE patients.HPV vaccines can effectively prevent HPV infection and subsequent HPV-related diseases.

Genetic Analysis and Fine Mapping of a Novel Semidominant Dwarfing Gene LB4D in Rice

A dwarf mutant,designated LB4D,was obtained among the progeny of backcrosses to a wild rice introgression line.Genetic analysis of LB4D indicated that the dwarf phenotype was controlled by a single semidominant dwarfing gene,which was named LB4D.The mutants were categorized as dn-type dwarf mutants according to the pattern of internode reduction.In addition,gibberellin（GA） response tests showed that LB4D plants were neither deficient nor insensitive to GA.This study found that tiller formation by LB4D plants was decreased by 40%compared with the wild type,in contrast to other dominant dwarf mutants that have been identified,indicating that a different dwarfing mechanism might be involved in the LB4D dominant mutant.The reduction of plant height in F1 plants ranged from 27.9%to 38.1%in different genetic backgrounds,showing that LB4D exerted a stronger dominant dwarfing effect. Using large F2 and F3 populations derived from a cross between heterozygous LB4D and the japonica cultivar Nipponbare,the LB4D gene was localized to a 46 kb region between the markers Indel 4 and Indel G on the short arm of chromosome 11,and four predicted genes were identified as candidates in the target region.