Genome wide investigation of Hsf gene family in Phoebe bournei:identification,evolution,and expression after abiotic stresses

Heat shock transcription factors(Hsfs)have important roles during plant growth and development and responses to abiotic stresses.The identification and func-tion of Hsf genes have been thoroughly studied in various herbaceous plant species,but not woody species,especially Phoebe bournei,an endangered,unique species in China.In this study,17 members of the Hsf gene family were identi-fied from P.bournei using bioinformatic methods.Phyloge-netic analysis indicated that PbHsf genes were grouped into three subfamilies:A,B,and C.Conserved motifs,three-dimensional structure,and physicochemical properties of the PbHsf proteins were also analyzed.The structure of the PbHsf genes varied in the number of exons and introns.Pre-diction of cis-acting elements in the promoter region indi-cated that PbHsf genes are likely involved in responses to plant hormones and stresses.A collinearity analysis dem-onstrated that expansions of the PbHsf gene family mainly take place via segmental duplication.The expression levels of PbHsf genes varied across different plant tissues.On the basis of the expression profiles of five representative PbHsf genes during heat,cold,salt,and drought stress,PbHsf pro-teins seem to have multiple functions depending on the type of abiotic stress.This systematic,genome-wide investigation of PbHsf genes in P.bournei and their expression patterns provides valuable insights and information for further func-tional dissection of Hsf proteins in this endangered,unique species.

Toxic and Antifeedant Effects of Different Pesticidal Plant Extracts against Beet Armyworm (Spodoptera exigua)

The beet armyworm(BAW),Spodoptera exigua(Lepidoptera:Noctuidae)is a highly destructive pest of vegetables and field crops.Management of beet armyworm primarily relies on synthetic pesticides,which is threatening the beneficial community and environment.Most importantly,the BAW developed resistance to synthetic pesticides with making it difficult to manage.Therefore,alternative and environment-friendly pest management tactics are urgently required.The use of pesticidal plant extracts provides an effective way for a sustainable pest management program.To evaluate the use of pesticidal plant extracts against BAW,we selected six plant species(Lantana camara,Aloe vera,Azadirachta indica,Cymbopogon citratus,Nicotiana tabacum,and Ocimum basilicum)for initial screening experiment.Four out of six plant species such as A.indica,N.tabacum,C.citratus and O.basilicum showed promising mortality of more than 50%.Therefore,we selected these four plant extracts for the subsequent experiments.Through contact bioassay,A.indica showed high mortality 66.63%,followed by the N.tabacum 53.33%,at 10%w/v concentration.Similarly,N.tabacum showed the highest mortality rate,66%at 10%w/v concentration,followed by the A.indica 46%through feeding bioassay.Furthermore,the feeding deterrence assay showed that C.citratus had a high antifeedant index(−50)followed by A.indica(−39),and N.tabacum(−28).In living plant assay,the N.tabacum extract showed a low mean damage score 3.6 on living cotton plant followed by C.citratus 4.5 and A.indica 5.5.Hence,extracts of three plant species provided promising results against the BAW,which can minimize the use of synthetic chemicals,particularly for small landholding farmers.Further studies are also required to evaluate the effects of these plant extract against BAW on cotton plants under field conditions to optimize the further use.

Isolation and identification of Fusarium oxysporum f. sp. cubense in Fujian Province, China

Fusarium wilt, caused by Fusarium oxyporum f. sp. cubense(Foc), is the most serious disease affecting banana production.To clarify the distribution of the Foc races in Fujian Province of China, 79 soil samples were collected from four regions of Zhangzhou City, the primary banana production area in Fujian. We isolated and identified 12 Foc strains based on internal transcribed spacer(ITS) sequence analysis, PCR amplification by using Foc-specific primers and pathogenicity assays.Our analysis indicated that 11 isolates belong to Foc race 1, and 1 isolate belongs to the Foc tropical species race 4(TR4).Although TR4 has previously been reported to occur in primary banana-producing provinces, such as Hainan, Guangxi,and Guangdong of China, this is the first report of TR4 isolated from the soil in Fujian Province. Monitoring the presence of Foc, in particular, the TR4 strains in the soil, is the basic strategy to prevent and control Fusarium wilt.

Development of Species-Specific PCR Primers and Sensitive Detection of the Tylenchulus semipenetrans in China

Tylenchulus semipenetrans is the most economically important and widespread nematode pest of citrus in China.rDNA-ITS of 14 populations of T.semipenetrans which were collected from different citrus groves or Chinese fir（Cunninghamia lanceolata） plantations in China were amplified and sequenced.The species-specific primers were designed for the first time to diagnosis T.semipenetrans based on the sequences of rDNA-ITS regions of geographic population above.The primers were sensitive to amplify the expected band size（297 bp） from DNA template of a single second-stage juvenile（J2） or different life stages of T.semipenetrans.No specific band was amplified from 15 non-target nematode species which were commonly found in citrus groves.Specificity and reliability of the primers were validated by further PCR amplification of 16 extra populations of T.semipenetrans collected from 4 provinces of China.The primers successfully detected a single J2 of T.semipenetrans within a whole nematode community comprising a large numbers of non-target nematode.The developed diagnostic technique can be used for accurate identification of T.semipenetrans and also as a decision tool for nematode management for citrus or Chinese fir in China.

Tradeoff between triglyceride consumption and ovariole development in Plutella xylostella(L.) released in mixed-host environments

After exposure to mixed environments with multiple hosts, the frequency of flight take-offs for Plutella xylostella(L.) is known to increase with a concomitant decrease in female fecundity. The objective of the present study was to elucidate the physiological mechanism underlying the increased flight activity and decreased fecundity of P. xylostella in mixed-host environments. We measured ovariole length, and triglyceride and vitellogenin(Vg) content in P. xylostella females after they were released into different host environments consisting of either a single host(Brassica campestris, Brassica oleracea or Brassica juncea) or a mixture of all three hosts. Our results indicated that ovariole length varied significantly between female adults from different host environments. Females from the B. campestris environment had the longest ovarioles, whereas those from the mixed environment had the shortest ones. A negative correlation was found between ovariole length and the flight take-off frequency of P. xylostella adults. Additionally, there were significant differences in the triglyceride content of P. xylostella females from different host environments. Our data revealed that more triglyceride was consumed by P. xylostella female adults from B. oleracea and the mixed environments than those from environments containing only B. campestris or B. juncea. In contrast, the relative Vg content in P. xylostella females from the mixed environment was lower than that in females from the B. campestris-, B. juncea-or B. oleracea-only environments. In conclusion, the mixed environment caused increased consumption of available energy resources(triglyceride) at the cost of retarding ovarian development and decreasing the amount of Vg produced.

Changes in the epigenome and transcriptome of rice in response to Magnaporthe oryzae infection

DNA methylation participates in regulating the expression of coding and non-coding regions in plants. To investigate the association between DNA methylation and pathogen infection, we used whole-genome bisulfite sequencing to survey temporal DNA methylation changes in rice after infection with the rice blast fungus Magnaporthe oryzae. In contrast to previous findings in Arabidopsis, global DNA methylation levels in rice increased slightly after rice blast infection. We identified over 38,000 differentially methylated regions(DMRs), and hypermethylated DMRs far outnumbered hypomethylated DMRs. Most DMRs were located in transposable element regions. Using transcriptome analysis, we identified 8830 differentially expressed genes(DEGs) after 1, 3, and 5 days of infection. Over one-third of DEGs, most of which were CHH-type DMRs, were associated with DMRs. Functional analysis of the CHH DMR-DEGs indicated their involvement in many important biological processes, including cell communication and response to external stimulus. The transcription of many NBS-LRR family genes was affected by changes in DNA methylation, suggesting that DNA methylation plays essential roles in the response of rice to M. oryzae infection. More broadly, the DNA methylation analysis presented here sheds light on epigenomic involvement in plant defense against fungal pathogens.

Histone H3K27me3 methylation regulates the expression of secreted proteins distributed at fast-evolving regions through transcriptional repression of transposable elements

The fine-tuned expression dynamics of the effector genes are pivotal for the transition from vegetative growth to host colonization of pathogenic filamentous fungi.However,mechanisms underlying the dynamic regulation of these genes remain largely unknown.Here,through comparative transcriptome and chromatin immunoprecipitation sequencing(ChIP-seq)analyses of the methyltransferase PoKmt6 in rice blast fungus Pyricularia oryzae(syn.Magnaporthe oryzae),we found that PoKmt6-mediated H3K27me3 deposition was enriched mainly at fast-evolving regions and contributed to the silencing of a subset of secreted proteins(SP)and transposable element(TE)families during the vegetative growth of P.oryzae.Intriguingly,we observed that a group of SP genes,which were depleted of H3K27me3 modification,could also be silenced via the H3K27me3-mediated repression of the nearby TEs.In conclusion,our results indicate that H3K27me3 modification mediated by PoKmt6 regulates the expression of some SP genes in fast-evolving regions through the suppression of nearby TEs.

Synthesis and Crystal Structure of 3-(4-Chlorophenyl)-8-cyano-2-(di-isopropylamino)-5-methyl-7-(methylthio)-pyrido[4,3-d]pyrimidine-4(3H)-one

The crystal structure of the new title compound 3-（4-chlorophenyl）-8-cyano-2-（di-iso-propylamino）-5-methyl-7-（methylthio）-pyrido[4,3-d]pyrimidine-4（3H）-one（C22H24ClN5OS,Mr = 441.97）has been determined by single-crystal X-ray diffraction. The crystal is of orthorhombic,space group Pna21 with a = 7.6721（5）,b = 18.9370（11）,c = 15.6260（9）A,V = 2270.2（2）A^3,Z = 4,Dc = 1.293 g/cm^3,F（000）= 928,μ = 0.283 mm^-1,MoKa radiation（λ = 0.71073 A）,R = 0.0494 and wR = 0.1062 for 3278 observed reflections with I 〉 2σ（I）. X-ray diffraction analysis reveals that all ring atoms in the py-ridopyrimidinone moiety are almost coplanar. Intramolecular C（20）-H（20）···N（4）,C（19）-H（19A）···N（3）,C（18）-H（18C）···N（3）and C（16）-H（16B）···O（5）hydrogen bonds together with weak C···π interactions are found in the structure.

Factors Influencing Farmers' Willingness to Participate in Plant Protection Machinery Subsidies

In order to have an overview of implementation of the subsidy policy for purchase of plant protection machinery in Fujian Province, based on the questionnaire data on Fujian Province, we use Logit model to conduct empirical analysis of factors influencing farmers' willingness to participate in the subsidy policy for purchase of plant protection machinery. Research results show that there are 69.4% of farmers willing to participate in the subsidy policy for purchase of plant protection machinery; farmers' growing area has a significant impact on the willingness to participate in the subsidy policy for purchase of plant protection machinery, and there is negative correlation; educational level, experience in planting, family farming pure income all have a significant positive impact on the willingness to participate in the subsidy policy.

The sigma 54 genes rpoN1 and rpoN2 of Xanthomonas citri subsp. citri play different roles in virulence, nutrient utilization and cell motility

The sigma factor 54（σ^（54）） controls the expression of many genes in response to nutritional and environmental conditions. There are two σ^（54） genes, rpo N1（XAC1969） and rpo N2（XAC2972）, in Xanthomonas citri subsp. citri. To investigate their functions, the deletion mutants ΔrpoN1, ΔrpoN2 and ΔrpoN1N2 were constructed in this study. All the mutants delayed canker development in low concentration inoculation in citrus plants. The bacterial growth of mutants was retarded in the medium supplemented with nitrogen and carbon resources. Under either condition, the influence degree caused by deletion of rpoN 2 was larger than the deletion of rpoN 1. Remarkably, the mutant ΔrpoN 1 showed a reduction in cell motility, while the mutant Δrpo N2 increased cell motility. Our data suggested that the rpoN 1 and rpoN 2 play diverse roles in X. citri subsp. citri.

AGO2a but not AGO2b mediates antiviral defense against infection of wild-type cucumber mosaic virus in tomato

Evolutionarily conserved antiviral RNA interference(RNAi)mediates a primary antiviral innate immunity preventing infection of broad-spectrum viruses in plants.However,the detailed mechanism in plants is still largely unknown,especially in important agricultural crops,including tomato.Varieties of pathogenic viruses evolve to possess viral suppressors of RNA silencing(VSRs)to suppress antiviral RNAi in the host.Due to the prevalence of VSRs,it is still unknown whether antiviral RNAi truly functions to prevent invasion by natural wild-type viruses in plants and animals.In this research,for the first time we applied CRISPR-Cas9 to generate ago2a,ago2b,or ago2ab mutants for two differentiated Solanum lycopersicum AGO2s,key effectors in antiviral RNAi.We found that AGO2a but not AGO2b was significantly induced to inhibit the propagation of not only VSR-deficient Cucumber mosaic virus(CMV)but also wild-type CMV-Fny in tomato;however,neither AGO2a nor AGO2b regulated disease induction after infection with either virus.Our findings firstly reveal a prominent role of AGO2a in antiviral RNAi innate immunity in tomato and demonstrate that antiviral RNAi evolves to defend against infection of natural wild-type CMV-Fny in tomato.However,AGO2a-mediated antiviral RNAi does not play major roles in promoting tolerance of tomato plants to CMV infection for maintaining health.

Plant virology in the 21st century in China:Recent advances and future directions

Plant viruses are a group of intracellular pathogens that persistently threaten global food security.Significant advances in plant virology have been achieved by Chinese scientists over the last 20 years,including basic research and technologies for preventing and controlling plant viral diseases.Here,we review these milestones and advances,including the identification of new crop-infecting viruses,dissection of pathogenic mechanisms of multiple viruses,examination of multilayered interactions among viruses,their host plants,and virus-transmitting arthropod vectors,and in-depth interrogation of plantencoded resistance and susceptibility determinants.Notably,various plant virus-based vectors have also been successfully developed for gene function studies and target gene expression in plants.We also recommend future plant virology studies in China.

The Magnaporthe oryzae effector Avr-PikD suppresses rice immunity by inhibiting an LSD1-like transcriptional activator

Avirulence effectors(Avrs),encoded by plant pathogens,can be recognized by plants harboring the corresponding resistance proteins,thereby initiating effector-triggered immunity(ETI).In susceptible plants,however,Avrs can function as effectors,facilitating infection via effector-triggered susceptibility(ETS).Mechanisms of Avr-mediated ETS remain largely unexplored.Here we report that the Magnaporthe oryzae effector Avr-PikD enters rice cells via the canonical cytoplasmic secretion pathway and suppresses rice basal defense.Avr-PikD interacts with an LSD1-like transcriptional activator AKIP30 of rice,and AKIP30 is also a positive regulator of rice immunity,whereas Avr-PikD impedes its nuclear localization and suppresses its transcriptional activity.In summary,M.oryzae delivers Avr-PikD into rice cells to facilitate ETS by inhibiting AKIP30-mediated transcriptional regulation of immune response against M.oryzae.

Windborne migration routes of newly-emerged fall armyworm from Qinling Mountains-Huaihe River region,China

The fall armyworm(FAW,Lepidoptera:Noctuidae),Spodoptera frugiperda(J.E.Smith),invaded China in mid-December 2018;since then,it has become a great threat to Chinese agricultural production.Qinling Mountains-Huaihe River region(QM-HRR)is the transitional zone between northern and southern China,an important region for both corn and wheat production.Based on the actual occurrence of QM-HRR invaded by FAW in 2019,daily mean surface air temperature and nocturnal wind conditions at 925 hPa were examined,and migratory routes of FAW moths originated in QM-HRR were modeled by a forward-trajectory-analysis approach.The results indicated that migratory activities of FAW adults emerged in QM-HRR were initiated from late June.The moths from western QM-HRR,where has complex topographic terrain,mainly flied to Ningxia and Inner Mongolia before mid September.However,FAW moths from the eastern QM-HRR primarily engaged in high-altitude northward transport assisted by the prevailing southerly winds before mid August,and the North China Plain was identified as the main destination of FAW.Meanwhile,the migration trajectories of FAW moths had a possibility to reach the Northeast China Plain.From mid August,FAW moths in eastern QM-HRR largely migrated southward and returned to the Yangtze River Valley.This study provides detailed information on the occurrence and migration routes of FAW moths from QM-HRR and will be helpful for early warning and development of integrated pest management strategies for the control of this exotic insect pest.

A Rapid Identification Method of Bactrocera cilifera (Hendel) with Species-Specific Primers(SS-COI)

[Objective]The paper was to establish a rapid identification method of Bactrocera cilifera(Hendel)with species-specific primers(SS-COI).[Method]Using B.cilifera(Hendel)as the positive control,and 19 species of fruit flies such as B.diaphora(Coquillett)and B.dorsalis(Hendel)as the negative controls,a pair of species-specific primers,YF290 and YR511,were designed and screened for accurate identification of B.cilifera,based on mitochondrial DNA COI sequence.[Result]The PCR products were amplified and detected by electrophoresis.Only a clear and single band was observed at about 222 bp in the positive control,while no bands were found in the other negative controls.[Conclusion]The established rapid identification method with species-specific primers(SS-COI)is of great practical significance for rapid identification of fruit flies intercepted from import and export fruits and vegetables at ports,and for rapid clearance and early warning of import fruits and vegetables at ports.

Identification of Bulbocodin D and C as novel STAT3 inhibitors and their anticancer activities in lung cancer cells

Cancer stands as one of the predominant causes of mortality globally, necessitating ongoing efforts to develop innovative therapeutics. Historically, natural products have been foundational in the quest for anticancer agents. Bulbocodin D (BD) and Bulbocodin C (BC), two bibenzyls derived from Pleione bulbocodioides (Franch.) Rolfe, have demonstrated notable in vitro anticancer activity. In human lung cancer A549 cells, the IC50s for BD and BC were 11.63 and 11.71 μmol·L^(−1), respectively. BD triggered apoptosis, as evidenced by an upsurge in Annexin V-positive cells and elevated protein expression of cleaved-PARP in cancer cells. Furthermore, BD and BC markedly inhibited the migratory and invasive potentials of A549 cells. The altered genes identified through RNA-sequencing analysis were integrated into the CMap dataset, suggesting BD’s role as a potential signal transducer and activator of transcription 3 (STAT3) inhibitor. SwissDock and MOE analyses further revealed that both BD and BC exhibited a commendable binding affinity with STAT3. Additionally, a surface plasmon resonance assay confirmed the direct binding affinity between these compounds and STAT3. Notably, treatment with either BD or BC led to a significant reduction in p-STAT3 (Tyr 705) protein levels, regardless of interleukin-6 stimulation in A549 cells. In addition, the extracellular signal-regulated kinase (ERK) was activated after BD or BC treatment. An enhancement in cancer cell mortality was observed upon combined treatment of BD and U0126, the MEK1/2 inhibitor. In conclusion, BD and BC emerge as promising novel STAT3 inhibitors with potential implications in cancer therapy.

Biogeographical affinities and evolution of terrestrial fauna in the Qinghai-Tibetan Plateau and the Himalayas:a case study of Aphidomorpha

The history of the Qinghai-Tibetan Plateau and the Himalayas(QTPH)region makes it a‘living laboratory'for understanding how the Earth's abiotic evolution has shaped regional biotas.However,no studies to date have attempted to investigate general macro-scale biogeographical patterns and biogeographical affinities of the QTPH terrestrial fauna in a global context.Based on the analyses of the global distributions of QTPH Aphidomorpha species,we examined generalized distribution patterns for them and investigated the biogeographical affinities between the QTPH and other regions.Track analysis and cluster analysis of the global distributions of 298 Aphidomorpha species in the QTPH identified seven generalized biogeographical tracks and eight general distribution patterns.Both approaches detected similarly generalized distribution patterns.Four marginal areas where the generalized tracks intersect,i.e.the eastern Himalayas,the western Himalayas,the Hengduan Mountains,and the northeastern QTPH,were identified as biogeographical nodes.The generalized distribution patterns indicate the biogeographical affinities between the QTPH and other regions and suggest the complex nature of the QTPH fauna.A spatial congruence between the nodes and diversity centres detected by previous studies indicates the four marginal areas have been key areas in fauna evolution as centres for faunal exchange as well as glacial refugia.Based on the biogeographical patterns,the geological history of the QTPH and the evolutionary history of Aphidomorpha,we propose an evolutionary scenario for the evolution of the QTPH aphid fauna in which faunal exchanges,vicariance due to the uplift of geographical barriers,environmental heterogeneity and Quarternary glaciations have shaped the diversity patterns and fauna in the QTPH.

Interplay of transport vesicles during plant-fungal pathogen interaction

Vesicle trafficking is an essential cellular process upon which many physiological processes of eukaryotic cells rely.It is usually the‘language’of communication among the components of the endomembrane system within a cell,between cells and between a cell and its external environment.Generally,cells have the potential to internalize membrane-bound vesicles from external sources by endocytosis.Plants constantly interact with both mutualistic and pathogenic microbes.A large part of this interaction involves the exchange of transport vesicles between the plant cells and the microbes.Usually,in a pathogenic interaction,the pathogen releases vesicles containing bioactive molecules that can modulate the host immunity when absorbed by the host cells.In response to this attack,the host cells similarly mobilize some vesicles containing pathogenesis-related compounds to the pathogen infection site to destroy the pathogen,prevent it from penetrating the host cell or annul its influence.In fact,vesicle trafficking is involved in nearly all the strategies of phytopathogen attack subsequent plant immune responses.However,this field of plant-pathogen interaction is still at its infancy when narrowed down to plant-fungal pathogen interaction in relation to exchange of transport vesicles.Herein,we summarized some recent and novel findings unveiling the involvement of transport vesicles as a crosstalk in plant-fungal phytopathogen interaction,discussed their significance and identified some knowledge gaps to direct future research in the field.The roles of vesicles trafficking in the development of both organisms are also established.

HOST PLANT PREFERENCES OF BEMISIA TABACI GENNADIUS

The preferences of Bemisia tabaci Gennadius for five host plants:poinsettia, tomato, cabbage,sweet potato and flowering Chinese cabbage, was tested using a Y-tube olfactometer and a desiccator in the labo-ratory. The results show that B. tabaci adults were attracted by the odors of the five plants. The order of prefer-ence was poinsettia > flowering Chinese cabbage > sweet potato > cabbage > tomato. Preference was extremely sig-nificant between poinsettia and the other four plants, and between flowering Chinese cabbage, cabbage and toma-to. There was no significant difference in preference for flowering Chinese cabbage and sweet potato, sweet pota-to, cabbage and tomato or between cabbage and tomato.

Taxonomic confusion of two tramp ant species： Iridomyrmex anceps and Ochetellus glaber are really species complexes

Many invasive invertebrates belong to unresolved species complexes, and have a history of misidentification and in-appropriate management. Here we detail confusion surrounding the taxonomy and identification of two dolichoderine ant species, Iridomyrmex anceps Roger and OcheteUus glaber Mayr, which are commonly cited in the literature as having been spread widely by human commerce. We provide morphometric data and images strongly suggesting that these two ＂species＂ are instead com- plexes of species that are likely native to many regions where they are purportedly introduced. We take particular interest in the status of species referred to as L anceps and O. glaber in China, as this is the most northerly distribution of both genera. We con-clude by suggesting that many identifications of both species are likely to be unreliable, and we recommend against any manage- ment action aimed at controlling these species under the assumption that they are exotic [Current Zoology 57 （5）： 662-667, 2011].