The wheat aphid Sitobion miscanthi (CWA) is an important harmful pest in wheat fields. Insecticide application is the main method to effectively control wheat aphids. However, CWA has developed resistance to some insecticides due to its extensive application, and understanding resistance mechanisms is crucial for the management of CWA. In our study, a new P450 gene, CYP4CJ6 , was identified from CWA and showed a positive response to imidacloprid and thiamethoxam. Transcription of CYP4CJ6 was significantly induced by both imidacloprid and thiamethoxam, and overexpression of CYP4CJ6 in the imidacloprid-resistant strain was also observed. The sensitivity of CWA to these two insecticides was increased after the knockdown of CYP4CJ6 . These results indicated that CYP4CJ6 could be associated with CWA resistance to imidacloprid and thiamethoxam. Subsequently, the posttranscriptional regulatory mechanism was assessed, and miR-316 was confirmed to participate in the posttranscriptional regulation of CYP4CJ6 . These results are crucial for clarifying the roles of P450 in the resistance of CWA to insecticides.

We report a scalable and controllable ultrasound-assisted strategy for the preparation of Vulcan XC-72 nanoparticles-decorated halloysite nanotubes (HNTs@VXC-72), which was applied to modify glassy carbon electrode (GCE) for the highly sensitive electrochemical determination of niclosamide (NA). For the HNTs@VXC-72 nanocomposite, VXC-72 nanoparticles with excellent electrical conductivity and good dispersing property contributed to the formation of the interconnected conductive network; HNTs possessed good adsorption performance and promoted the electrochemical redox reaction. The research results showed that the combination of VXC-72 nanoparticles and HNTs produced the effect of synergistic enhancement. The HNTs@VXC-72/GCE sensor could show a relatively low detection limit of 3.28 nM in the great linear NA concentration range of 0.01-1 mu M. When used for the NA determination in food samples, the HNTs@VXC-72/GCE sensor exhibited good practical feasibility with low RSD and acceptable recoveries, which provided a promising NA determination approach to ensure food safety.

Camellia oleifera Abel. is an economically important tree that produces edible oils and flowers and fruits in late autumn and early winter. However, low temperatures lead to low yields because of the absence of normal pollination and fertilization. In this study, a pot experiment was conducted to understand the effects of temperature (6 degrees C, 25 degrees C, and control) on florescence, photosynthesis, physiological response, and anatomical structure in two Camellia cultivars (Hua Shuo and Hua. Xin) for 25 days. Low-temperature stress (6 degrees C) decreased net photosynthetic rate, transpiration rate, stomatal conductance, chlorophyll content, and maximum quantum yield of PSII photochemistry of the two cultivars. Initial fluorescence, leaf thickness, and soluble sugar and malondialdehyde contents increased in the low-temperature treatment compared to the normal temperature (25 degrees C). Low-temperature stress (6 degrees C) destroyed chloroplast morphology and structure. In addition, it inhibited the normal opening of Hua Xin and normal temperature promoted the growth of young fruits. However, the flowers of Hua Shuo bloomed, the stamens and pistils withered but did not fall off, and for the first time it was discovered that a significant amount of mucus appeared at the base of the flower under low temperature. The mechanism of secretion of the mucus is unknown and merits further investigation. In summary, these results suggest that C. oleifera has a high fruit setting rate under normal temperature. Low temperature, even 6 degrees C, significantly reduced photosynthetic efficiency and the fruit setting rate. In addition, Hua Shuo had better cold tolerance than Hua Xin, but young fruit of Hua Xin grew faster than Hua Shuo at the normal temperature. (C) 2020 Friends Science Publishers

A poorly known perlid species, Flavoperla ovalolobata (Wu, 1948) is redescribed based on an adult male and four females newly collected at the type locality, Wuyishan located in Fujian Province of southeastern coastal China. Illustrations and color photographs are provided for this species. The taxonomic relationship of this taxon is discussed with related taxa.

Two species of the perlid genus Neoperla of the montivaga species group, N. longispina Wu, 1938 and N. minor Chu, 1929, are redescribed from Hainan and Zhejiang provinces of China, respectively. Neotypes are designated for both taxa. Illustrations and color photographs are provided for each species. Their taxonomic relationships are discussed with related congeners.

Tung tree (Vernicia fordii), an economically important woody oil plant, is a monoecious and diclinous species with male and female flowers on the same inflorescence. The extremely low proportion of female flowers leads to low fruit yield in tung orchards. The female flower normally develops along with stamen abortion; otherwise sterile ovules will be produced. However, little knowledge is known about the molecular basis of the female flower development in tung tree. In this study, integrated analyses of morphological and cytological observations, endogenous phytohormone assay and RNA-seq were conducted to understand the molecular mechanism of the female flower development in tung tree. Cytological observation suggested that the abortion of stamens in female flowers (SFFs) belongs to the type of programmed cell death (PCD), which was caused by tapetum degeneration at microspore mother cell stage. A total of 1,366 differentially expressed genes (DEGs) were identified in female flowers by RNA-seq analysis, of which 279 (20.42%) DEGs were significantly enriched in phenylpropanoid biosynthesis, phenylalanine metabolism, flavonoid biosynthesis, starch and sucrose metabolism, and plant hormone signal transduction. Stage-specific transcript identification detected dynamically expressed genes of important transcription regulators in female flowers that may be involved in PCD and floral organ development. Gene expression patterns revealed that 17 anther and pollen development genes and 37 PCD-related genes might be involved in the abortion of SFF. Further analyses of phytohormone levels and co-expression networks suggested that salicylic acid (SA) accumulation could trigger PCD and inhibit the development of SFF in tung tree. This study provides new insights into the role of SA in regulating the abortion of SFF to develop normal female flowers.

In recent years, it is a hotspot research field on interaction mechanism between elicitor and plant. In this study, a novel hypersensitive response (HR)-inducing protein elicitor was isolated from the culture filtrate of Fusarium oxysporum f. sp. cubense and named PeFOC1, which consisted of 321 amino acids with a molecular weight of approximately 35 kDa. After the inducible expression in Escherichia coli and purification by ÄKTA explore system, the recombinant PeFOC1 also triggered a typical HR in tobacco. In addition, PeFOC1 induced a cascade of defense response in tobacco including production of hydrogen peroxide, deposition of callose, and accumulation of phenolic compounds. Moreover, PeFOC1 significantly improved systemic resistance of tobacco seedlings to tobacco mosaic virus and Pseudomonas syringae pv. tabaci. Real-time quantitative-PCR analysis indicated that several defense-related genes in tobacco, such as NtPR1a, NtNPR1, NtPAL, NtEDS1, NtPDF, and NtLOX, were all up-regulated by the treatment of PeFOC1. All these results collectively demonstrated that PeFOC1 triggered defense response and systemic acquired resistance (SAR) in tobacco. This research not only provides further research on immune mechanism between plant and elicitor, but also sheds new light on strategy for biocontrol in the future.

Panama disease, or Fusarium wilt, the most serious disease in banana cultivation, is caused by Fusarium oxysporum f. sp. cubense (FOC) and has led to great economic losses worldwide. One effective way to combat this disease is by enhancing host plant resistance. The cerato-platanin protein (CPP) family is a group of small secreted cysteine-rich proteins in filamentous fungi. CPPs as elicitors can trigger the immune system resulting in defense responses in plants. In this study, we characterized a novel cerato-platanin-like protein in the secretome of Fusarium oxysporum f. sp. cubense race 4 (FOC4), named FocCP1. In tobacco, the purified recombinant FocCP1 protein caused accumulation of reactive oxygen species (ROS), formation of necrotic reaction, deposition of callose, expression of defense-related genes, and accumulation of salicylic acid (SA) and jasmonic acid (JA) in tobacco. These results indicated that FocCP1 triggered a hypersensitive response (HR) and systemic acquired resistance (SAR) in tobacco. Furthermore, FocCP1 enhanced resistance tobacco mosaic virus (TMV) disease and Pseudomonas syringae pv. tabaci 6605 (Pst. 6605) infection in tobacco and improved banana seedling resistance to FOC4. All results provide the possibility of further research on immune mechanisms of plant and pathogen interactions, and lay a foundation for a new biological strategy of banana wilt control in the future.

Beta-hydroxyacyl-acyl carrier protein dehydratase (HAD) catalyzes the formation of enoyl-[ACP] from beta-hydroxylacyl-[ACP] and plays a key role in determining fatty acid composition during the process of oil biosynthesis. In this study, only one HAD gene (GenBank KU358903) was identified and isolated from tung tree (Vernicia fordii Hemsl.). The VfHAD contained an open reading frame (ORF) of 663 bp, encoding a polypeptide of 220 amino acid residues. It shared 86, 85, and 83% amino acid identities with the HADs of Hevea brasiliensis, Jatropha curcas, and Ricinus communis, respectively. The VfHAD exhibited all essential catalytic sites and the characteristic "hot-dog" structure of FabZ protein. Quantitative real-time PCR (qRT-PCR) analysis showed that VfHAD mRNA was detected in all tung tree organs, but its transcript was the most abundant in tung seeds at 20 weeks after flowering when oil rapidly accumulated. The VfHAD was localized in chloroplast. Heterologous expression of VfHAD significantly increased C16 fatty acids content in Escherichia coli, yeast, and tobacco. This study suggested that VfHAD may play a key role in fatty acid biosynthesis in tung seeds and could be a useful target for genetic improvement of oil quality.

Based on the conducted cDNA library of Camellia oleifera,two full-length cDNA genes were obtained,and were 953 bp and 1 024 bp,respectively,designated as CoCaM1 and CoCaM2 (GertBank access numbers:EU856536 and FJ649316).They shared high similarity at nucleotide level in the coding regions(CDS).They both contained the 447-bp CDS with 25 nucleotide substitutions,and encoded an identical polypeptide of 149 amino acids(predicted relative molecular weight of 16.83 kDa).The protein is a hydrophilic acidic protein,and comprised of 19 amino acids with pI(theoretical isoelectric point) of 4.10.The characteristic is consistent with the hypothesis "Multigenes possess an identical amino acid sequence".It possesses four EF-hand domains,cysteine and other enzymebinding sites,etc.The protein has some identical degree in hydrophilicity,flexible regions and antigenicity,and thus shows high flexibility.The blast and phylogenetic analysis indicated that the amino acid sequence of C oleifera CaM displayed highly homologous compared with those of other higher plants.The higher expression levels of CoCaM1 were observed in the stage from flower bud to ovary formation.The expression levels of CoCaM2 were much higher in fruit formation and oil accumulation,while in leaves and mature seeds were lower.This shows that they may play different roles in the development of flower buds,fruit formation and oil synthesis and accumulation.

Tung tree ( Vernicia fordii ) is an economically important tree widely cultivated for industrial oil production in China. To better understand the molecular basis of tung tree chloroplasts, we sequenced and characterized its genome using PacBio RS II sequencing platforms. The chloroplast genome was sequenced with 161,528 bp in length, composed with one pair of inverted repeats (IRs) of 26,819 bp, which were separated by one small single copy (SSC; 18,758 bp) and one large single copy (LSC; 89,132 bp). The genome contains 114 genes, coding for 81 protein, four ribosomal RNAs and 29 transfer RNAs. An expansion with integration of an additional rps19 gene in the IR regions was identified. Compared to the chloroplast genome of Jatropha curcas , a species from the same family, the tung tree chloroplast genome is distinct with 85 single nucleotide polymorphisms (SNPs) and 82 indels. Phylogenetic analysis suggests that V. fordii is a sister species with J. curcas within the Eurosids I. The nucleotide sequence provides vital molecular information for understanding the biology of this important oil tree.

Cyclophilins (CyPs) are ubiquitous proteins and involved in protein folding and stress response due to peptidyl-prolyl cis-trans isomerase (PPIase) activity. In this study, a 975-base pair (bp) full-length complementary DNA (cDNA) gene, Camellia oleifera CyP (CoCyP, GenBank access no. FJ377540), was isolated from the conducted cDNA library of C. oleifera seeds. This cDNA encodes a polypeptide of 207 amino acids, which has an endoplasmic-reticulum-localized signal sequence at its N-terminus, but not the typical signal sequence at its C-terminus. Moreover, its putative amino acid sequence shares highest identity with those of Arabidopsis thaliana CyPB (84%) and Triticum aestivum CyPB (81%), and possesses a highly conserved central core domain including cyclosporin A (CsA)-binding sites, the tetrapeptide Ala-Ala-Pro-Ala-binding sites, residues required for PPIase catalysis and an insertion of seven amino acids of unknown function. Collectively, it is suggested that the CoCyP protein belongs to CyPB and has PPIase activity. An approximately 21 kDa protein was expressed via the recombinant pET-30b(+)/CoCyP in Escherichia coli. In this study, we tentatively put forward to the hypothesis that the gene expressing during the peak of seed lipid biosynthesis, might correlate with the caused harmful products in the lipid biosynthesis process, and protect cells against reactive oxygen species (ROS) damage; thus it may be crucial during lipid biosynthesis and stress responsiveness.

The genomic DNA extracted from tender leaves of 23 elite clones of Camellia oleifera(Native species for edible oil in China)was used to perform ISSR(inter-simple sequence repeat)analysis.Of the 60 primers screened,10 pieces of DNA fingerprint profiles containing 102 bands with 70 distinct polymorphic bands(68.6%)were obtained,and each primer produced 3 to 10 bands with the band size ranging from 200 bp to 2 000 bp.Result indicated that Shannon's information index was 0.479 3,and the mean observed number of alleles and the mean effective number of alleles were 2.000 0 and 1.518 5,respectively.The genetic distance varied from 0.154 2 to 0.693 1.There exists abundant polymorphism among these elite clones of C.oleifera.The UPGMA analysis result shows that the 23 elite clones of C.oleifera could be classified into 4 groups,namely,18 elite clones(including Xianglin 156,Xianglin 210,Xianglin 4,etc)belong to the first group,Jinruan 2 and Xianglin 97 to the second group,Xianglin 34 and Xianglin 11 to the third group,Xianglin 81 to the fourth group when the genetic distance is 0.392.On the basis of these analyses,the relationship between the clustering result and the agricultural characters of C.oleifera was discussed,which provides some references for the identification of elite clones,phylogenetic analyses and the utilization of germplasm resources.

Chalcone synthase(CHS) and chalcone isomerase(CHI) are the key enzymes controlling the metabolism of flavonoid and anthocyanin.In this paper,1 full-length cDNA of CHS and 1 full-length cDNA of CHI were separated from the cDNA library and EST library of Camellia oleifera by the method of molecular cloning.The cDNA of C.oleifera CHS contains 1 479 bp for 412 amino acids,which is so far the longest CHS and displays high evolution homology with those other species for very high similarity.The cDNA of C.oleifera CHI contains 899 bp for 206 amino acids,and displays high homology with that of Camellia sinensis,but relatively low similarity with the other species.

To investigate the gene expression and to separate clones which are important genes related to oil synthesis and so on during transforming peak of seed oil in Camellia oleifera, cDNA library was constructed using the nearly matured seeds of two clones, i.e. XL_1 and XL_4, and 2 327 clones were randomly selected for sequencing on the 3′_end to construct the EST library, and 1 979 sequences which are unabridged and without X or N were performed homology comparison with nucleic acid NR database. 763 cDNA sequences were highly homological to cDNA sequences of other plant species in database of NCBI, 266 kinds of genes have been identified and 1 216 clones of cDNA were unknown function of gene sequences. In the cDNA library of seeds of C. oleifera, different genes expressed different abundance. The genes related to storage protein, to expression and regulation, to resistance, to seed maturation and to embryo development were expressed in high abundance, while the genes related to metabolism of fatty acids etc. were expressed in medium abundance. The other genes responsible for many fragments and many genes unknown functions were expressed in different extent. The number and trends of expressed genes are suitable for the phase of C. oleifera seeds near to maturation.

以湘林1号和湘林4号油茶优良无性系近成熟种子为材料,总结了构建油茶种子cDNA文库过程中存在的一些关键问题和应采取的对策,为今后油茶和其它油料植物种子的mRNA提取、构建高质量的cDNA文库及ESTs文库等提供技术参考和理论指导.

转基因植物中抗性标记基因潜在的生态和食用安全性一直是颇有争论且悬而未决的问题.解决的途径有2条:一是选用安全性标记基因;二是开发、应用删除抗性标记基因新技术.综述了这两方面的研究进展.

以银杏幼叶为外植体,对银杏进行愈伤组织诱导和继代培养.通过正交试验设计,研究了不同浓度的3种激素配合使用对银杏愈伤组织诱导的效果,筛选出诱导银杏愈伤组织的最佳培养基:MS+3mg/LNAA+3mg/L6-BA.研究了在银杏愈伤组织继代过程中,不同浓度的4种抗氧化剂对褐变抑制的效果,筛选出最佳抗氧化剂及其浓度:10 mg/LVc.4种抗氧化剂对抑制褐变的效果如下:Vc>PVP>柠檬酸>Ac,其中,PVP的最佳浓度为1 g/L.继代过程中,光照条件对愈伤组织褐变程度有一定的影响.