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| 1 | Medicago AP2-Domain Transcription Factor WRI5a Is a Master Regulator of Lipid Biosynthesis and Transfer during Mycorrhizal Symbiosis显示文摘Most land plants have evolved a mutualistic symbiosis with arbuscular mycorrhiza (AM)fungi that improve nutrient acquisition from the soil.In return,up to 20% of host plant photosynthate is transferred to the mycorrhizal fungus in the form of lipids and sugar.Nutrient exchange must be regulated by both partners in order to maintain a reliable symbiotic relationship.However,the mechanisms underlying the regulation of lipid transfer from the plantto the AM fungus remain elusive.Here,we show that the Medicago truncatula AP2/EREBP transcription factor WRI5a,and likely its two homologs WRI5b/Erfl and WRI5c,are master regulators of AM symbiosis Controlling lipid transfer and periarbuscular membrane formation.We found that WRI5a binds AW-box cis-regulatory elements in the promoters of M.truncatula STR,which encodes a periarbuscular membrane-localized ABC transporter required for lipid transfer from the plant to the AM fungus, and MtPT4,whichr encodes a phosphate transporter required for phosphate transfer from the AM fungus to the plant.The hairy roots of the M.truncatula wti5a mutant and RNAi composite plants displayed impaired arbuscule formation,whereas overexpression of WRI5a resulted in enhanced expression of STR and MtPT4,suggesting that WRI5a regulates bidirectional symbiotic nutrient exchange.Moreover,we found that WRI5a and RAM1(Required for Arbuscular Mycorrhization symbiosis 1),which encodes a GRASdomain transcription factor,regulate each other at the transcriptional level,forming a positive feedback loop for regulatingAM symbiosis.Collectively,our data suggest a role for WRI5a in controlling bidirectional nutrient exchange and periarbuscular membrane formation via the regulation of genes involved in the biosynthesis of fatty acids and phosphate uptake in arbuscule-containing cells. | Yina Jiang Qiujin Xie Wanxiao Wang Jun Yang Xiaowei Zhang Nan Yu Yun Zhou Ertao Wang | 2018 | Molecular Plant2018，11，11： | 10 |
| 2 | A LysM Receptor Heteromer Mediates Perception of Arbuscular Mycorrhizal Symbiotic Signal in Rice显示文摘Symbiotic microorganisms improve nutrient uptake by plants.To initiate mutualistic symbiosis with arbus-cular mycorrhizal(AM)fungi,plants perceive Myc factors,including lipochitooligosaccharides(LCOs)and short-chain chitooligosaccharides(CO4/CO5),secreted by AM fungi.However,the molecular mechanism of Myc factor perception remains elusive.In this study,we identified a heteromer of LysM receptor-like kinases consisting of OsMYR1/OsLYK2 and OsCERK1 that mediates the perception of AM fungi in rice.CO4 directly binds to OsMYR1,promoting the dimerization and phosphorylation of this receptor complex.Compared with control plants,Osmyr1 and Oscerk1 mutant rice plants are less sensitive to Myc factors and show decreased AM colonization.We engineered transgenic rice by expressing chimeric receptors that respectively replaced the ectodomains of OsMYR1 and OsCERK1 with those from the homologous Nod factor receptors MtNFP and MtL YK3 of Medicago truncatula.Transgenic plants displayed increased cal-cium oscillations in response to Nod factors compared with control rice.Our study provides significant mechanistic insights into AM symbiotic signal perception in rice.Expression of chimeric Nod/Myc recep-tors achieves a potentially important step toward generating cereals that host nitrogen-fixing bacteria. | Jiangman He Chi Zhang Huiling Dai Huan Liu Xiaowei Zhang Jun Yang Xi Chen Yayun Zhu Dapeng Wang Xiaofeng Qi Weichao Li Zhihui Wang Guoyong An Nan YU Zuhua He Yong-Fei Wang Youli Xiao Peng Zhang Ertao Wang | 2019 | Molecular Plant2019，12，12： | 9 |
| 3 | Effects of ectomycorrhizal fungal identity and diversity on subtropical tree competition显示文摘Aims Mycorrhizal fungi can re-distribute nutrients among plants through formation of underground common mycorrhizal networks and therefore may alter interspecific plant competition.However,the effect of ectomycorrhizal(EM)fungi on interspecific plant competition in subtropical forests is poorly understood.In this study,we investigated the effects of EM fungal identity and diversity on the outcome of interspecific competition of plant species in relation to different successional stages in a Chinese subtropical forest.Materials and Methods This study selected four woody plant species,i.e.a pioneer tree Pinus massoniana,a late-pioneer tree Quercus serrata,a midsuccessional tree Cyclobalanopsis glauca and a late-successional tree Lithocarpus glaber in a Chinese subtropical forest.The outcomes of interspecific competition were investigated in the seedlings of three plant pairs,i.e.between Cy.glauca and Pin.mas-soniana,between Q.serrata and Pin.massoniana,and between Li.glaber and Q.serrata in a pot experiment.In the Cy.glauca-Pin.massoniana combination,plants in monoculture and two-species mixture were uninoculated or inoculated with EM fungi Paxillus involutus,Pisolithus tinctorius,Cenococcum geophilum,Laccaria bicolor and a mixture of these four fungal species.In the Q.ser-rata-Pin.massoniana and Li.glaber-Q.serrata combinations,plants in monocultures and two-species mixtures were uninoculated or inoculated with EM fungi Pis.tinctorius,Ce.geophilum,La.bicolor and a mixture of these three fungal species.EM root colonization rate and seedling biomass of each plant species were measured,and the outcomes of interspecific competition were estimated using competitive balance index after 6-month cultivation.Important Findings All EM fungal inoculation significantly promoted a competitive ability of the mid-successional tree Cy.glauca over the pioneer tree Pin.massoniana compared with the uninoculated control treatment,and the extent to which EM fungi affected the outcome of interspecific competition was dependent on EM fungal identity in the Cy.glauca and Pin.massoniana combination.EM fungal inoculation had no significant effect on the outcomes of interspecific competition between the late-pioneer tree Q.serrata and Pin.massoniana combination and between the late-successional tree Li.glaber and Q.serrata combination,compared with the uninoculated control treatment.However,amongst the EM fungal inoculation treatments the competitive ability of Q.serrata over Pin.massoniana was significantly higher in EM fungi Ce.geophilum and La.bicolor treatments than in Pis.tinctorius treatment.EM fungal diversity did not show a complementary effect on the outcomes of interspecific competition in all three plant pairs.This study demonstrated that the effect of EM fungi on the outcome of interspecific competition was dependent on the plant pairs tested in the subtropical forest ecosystem. | Nan-Nan Shi Cheng Gao Yong Zheng Liang-Dong Guo | 2017 | Journal of Plant Ecology2017，10，1： | 7 |
| 4 | Mycorrhizal symbiosis modulates the rhizosphere microbiota to promote rhizobia–legume symbiosis显示文摘Plants establish symbioses with mutualistic fungi,such as arbuscular mycorrhizal(AM)fungi,and bacteria,such as rhizobia,to exchange key nutrients and thrive.Plants and symbionts have coevolved and represent vital components of terrestrial ecosystems.Plants employ an ancestral AM signaling pathway to establish intracellular symbioses,including the legume–rhizobia symbiosis,in their roots.Nevertheless,the relationship between the AM and rhizobial symbioses in native soil is poorly understood.Here,we examined how these distinct symbioses affect root-associated bacterial communities in Medicago truncatula by performing quantitative microbiota profiling(QMP)of 16S rRNA genes.We found that M.truncatula mutants that cannot establish AM or rhizobia symbiosis have an altered microbial load(quantitative abundance)in the rhizosphere and roots,and in particular that AM symbiosis is required to assemble a normal quantitative root-associated microbiota in native soil.Moreover,quantitative microbial co-abundance network analyses revealed that AM symbiosis affects Rhizobiales hubs among plant microbiota and benefits the plant holobiont.Through QMP of rhizobial rpoB and AM fungal SSU rRNA genes,we revealed a new layer of interaction whereby AM symbiosis promotes rhizobia accumulation in the rhizosphere of M.truncatula.We further showed that AM symbiosis-conditioned microbial communities within the M.truncatula rhizosphere could promote nodulation in different legume plants in native soil.Given that the AM and rhizobial symbioses are critical for crop growth,our findings might inform strategies to improve agricultural management.Moreover,our work sheds light on the co-evolution of these intracellular symbioses during plant adaptation to native soil conditions. | Xiaolin Wang Huan Feng Yayu Wang Mingxing Wang Xingguang Xie Huizhong Chang Like Wang Jicheng Qu Kai Sun Wei He Chunyan Wang Chuanchao Dai Zhaohui Chu Changfu Tian Nan Yu Xuebin Zhang Huan Liu Ertao Wang | 2021 | Molecular Plant2021，14，3： | 6 |
| 5 | The price of protection:a defensive endosymbiont impairs nymph growth in the bird cherry-oat aphid,Rhopalosiphum padi显示文摘Bacterial endosymbionts have enabled aphids to adapt to a range of stressors,but their effects in many aphid species remain to be established.The bird cherry-oat aphid,Rhopalosiphum padi(Linnaeus),is an important pest of cereals worldwide and has been reported to form symbiotic associations with Serratia symbiotica and Sitobion miscanthi L-type symbiont endobacteria,although the resulting aphid phenotype has not been described.This study presents the first report of R.padi infection with the facultative bacterial endosymbiont Hamiltonella defensa.Individuals of R.padi were sampled from populations in Eastern Scotland,UK,and shown to represent seven R.padi genotypes based on the size of polymorphic microsatellite markers;two of these genotypes harbored H.defensa.In parasitism assays,survival of H.defensa-infected nymphs following attack by the parasitoid wasp Aphidius colemani(Viereck)was 5 fold higher than for uninfected nymphs.Aphid genotype was a major determinant of aphid performance on two Hordeum species,a modern cultivar of barley H.vulgare and a wild relative H.spontaneum,although aphids infected with H.defensa showed 16%lower nymph mass gain on the partially resistant wild relative compared with uninfected individuals.These findings suggest that deploying resistance traits in barley will favor the fittest R.padi genotypes,but symbiontinfected individuals will be favored when parasitoids are abundant,although these aphids will not achieve optimal performance on a poor quality host plant. | Daniel J.Leyboume Jorunn I.B.Bos Tracy A.Valentine Alison J.Karley | 2020 | Insect Science2020，27，1： | 5 |
| 6 | The exploitation of epichloae endophytes for agricultural benefit显示文摘Epichloae endophytes of family Clavicipitaceae(comprising genera Epichloëand Neotyphodium)are fungal symbionts of Pooideae grasses.The associations formed,range from mutually beneficial to antagonistic and the nature of this relationship is dependent upon the importance of vertical(via host seeds)versus horizontal(ascospore mediated)transmission of the fungus.These endophytes can enhance their hosts’survival through protection from abiotic and biotic stresses and can thus be utilized in an agricultural context.Animal-safe grass-endophyte associations that confer bio-protective properties for increased pasture persistence and productivity have been developed and commercialized.One of the crucial drivers underpinning the selection of epichloae strains for commercial development is endophyte derived bioactivity.The potential of next generation endophytes is determined by testing a number of attributes such as agronomic fitness,animal and food safety as well as compatibility with host plants of interest.Strategic research supports these activities by focusing on elucidating mechanisms of compatibility between host and fungal symbiont,as well as investigating other molecular drivers of symbiosis such as siderophore mediated iron-uptake,fungal signalling,fungal growth in host plants and fungal secondary metabolism.This review weaves together the different strands of multidisciplinary research aimed at ultimately exploiting epichloae endophytes for increased pasture performance. | Linda J.Johnson Anouck C.M.de Bonth Lyn R.Briggs John R.Caradus Sarah C.Finch Damien J.Fleetwood Lester R.Fletcher David E.Hume Richard D.Johnson Alison J.Popay Brian A.Tapper Wayne R.Simpson Christine R.Voisey Stuart D.Card | 2013 | Fungal Diversity2013，，3： | 5 |
| 7 | Endophytic mediation of reactive oxygen species and antioxidant activity in plants:a review显示文摘Reactive oxygen species are in all types of organisms from microbes to higher plants and animals.They are by-products of normal metabolism,such as photosynthesis and respiration,and are responsive to abiotic and biotic stress.Accumulating evidence suggests reactive oxygen species play a vital role in programmed cell death,stress responses,plant defense against pathogens and systemic stress signaling in conjunction with antioxidant production.Here,we propose that reactive oxygen species and antioxidants,as both universal and evolutionarily conserved,are likely to play important role(s)in symbiotic interactions.To support this hypothesis we review the root and foliar fungal endophyte literature specific to fungal-plant symbiotum production of reactive oxygen species and antioxidants in response to stress.These asymptomatic fungi can produce antioxidants in response to both biotic and abiotic stress when grown in culture as well as in planta.In addition,there is a growing but nascent literature reporting a significant impact of endophyte colonization on the antioxidant activity of colonized(E+)hosts when compared to uncolonized(E-)hosts,especially when exposed to stress.Here we summarize general patterns emerging from the growing literature specific to antioxidant activity of endophytes in colonized hosts and bring up possible future research questions and approaches.The consequences of changes in reactive oxygen species production and increased antioxidant activity in the symbiotum appear to be beneficial in many instances;but costs are also indicated.Unexplored questions are:1)to what extent do antioxidants originating from the fungal endophyte mediate host metabolism,and thereby control host responses to endophyte colonization;(2)what role do fungal,plant,or symbiotum produced reactive oxygen species and antioxidants have in determining symbiotic outcome between extremes of pathogenicity and mutualism;and(3)what role if any,do the production of reactive oxygen species and their antioxidant counterparts play in the symbiotum’s ability to respond to changing selection pressures?If as the literature suggests,such endophyte imposed mediation can be utilized to foster increases in plant production in resource limited habitats then the utilization of fungal endophytes may prove useful in agronomic and conservation settings. | Cyd E.Hamilton P.E.Gundel M.Helander K.Saikkonen | 2012 | Fungal Diversity2012，，3： | 5 |
| 8 | GSK3-mediated stress signaling inhibits legume-rhizobium symbiosis by phosphorylating GmNSP1 in soybean显示文摘Legumes establish symbiotic associations with rhizobia for biological nitrogen fixation.This process is highly regulated by various abiotic stresses,but the underlying genetic and molecular mechanisms remain largely unknown.In this study,we discovered that the glycogen synthase kinase 3(GSK3)-like kinase,GmSK2-8,plays an important role in inhibiting symbiotic signaling and nodule formation in soybean(Glycine max)under salt stress.We found that GmSK2-8 is strongly induced in soybean under high-salt conditions,while GmSK2-8 could interact with two G.max Nodulation Signaling Pathway 1(GmNSP1)proteins,GmNSP1a and GmNSP1b;these key transcription factors are essential for rhizobial infection,nodule initiation,and symbiotic gene expression in soybean.Furthermore,we demonstrated that GmSK2-8 phosphorylates the LHRI domain of GmNSP1a,inhibits its binding to the promoters of symbiotic genes,and thus suppresses nodule formation under salt stress.Knockdown of GmSK2-8 and its close homologs also resulted in reduced plant sensitivity to salt stress during nodule formation.Taken together,our findings indicate that GSK3-like kinases directly regulate the activities of GmNSP1s to mediate salt-inhibited legume–rhizobium symbiosis,providing novel targets for improving symbiotic nitrogen fixation under environmental stress conditions in soybean and possibly other legumes. | Chunmei He Hui Gao Haijiao Wang Yun Guo Miao He Yaqi Peng Xuelu Wang | 2021 | Molecular Plant2021，14，3： | 5 |
| 9 | New insights into the transovarial transmission of the symbiont Rickettsia in whiteflies显示文摘Endosymbiont transmission via eggs to future host generations has been recognized as the main strategy for its persistence in insect hosts;however,the mechanisms for transmission have yet to be elucidated.Here,we describe the dynamic locations of Rickettsia in the ovarioles and eggs during oogenesis and embryogenesis in a globally significant pest whitefly Bemisia tabaci.Field populations of the whitefly have a high prevalence of Rickettsia,and in all Rickettsia-infected individuals,the bacterium distributes in the body cavity of the host,especially in the midgut,fat body,hemocytes,hemolymph,and near bacteriocytes.The distribution of Rickettsia was subjected to dynamic changes in the ovary during oogenesis,and our ultrastructural observations indicated that the bacteria infect host ovarioles during early developmental stages via two routes:(i)invasion of the tropharium by endocytosis and then transmission into vitellarium via nutritive cord and(ii)entry into vitellarium by hijacking bacteriocyte translocation.Most of the Rickettsia are degraded in the oocyte cytoplasm in late-stage oogenesis.However,a few reside beneath the vitelline envelope of mature eggs,spread into the embryo,and proliferate during embryogenesis to sustain high-fidelity transmission to the next generation.Our findings provide novel insights into the maternal transmission underpinning the persistence and spread of insect symbionts. | Hongwei Shan Yinquan Liu Junbo Luan Shusheng Liu | 2021 | Science China(Life Sciences)2021，64，7： | 3 |
| 10 | No Home without Hormones: How Plant Hormones Control Legume Nodule Organogenesis显示文摘The establishment of symbiotic nitrogen fixation requires the coordination of both nodule development and infection events.Despite the evolution of a variety of anatomical structures,nodule organs serve a common purpose in establishing a localized area that facilitates efficient nitrogen fixation.As in all plant developmental processes,the establishment of a new nodule organ is regulated by plant hormones.During nodule initiation,regulation of plant hormone signaling is one of the major targets of symbiotic signaling.We review the role of major developmental hormones in the initiation of the nodule organ and argue that the manipulation of plant hormones is a key requirement for engineering nitrogen fixation in non-legumes as the basis for improved food security and sustainability. | Jieshun Lin Manuel Frank Dugald Reid | 2020 | Plant Communications2020，1，5： | 3 |
| 11 | Rhizobial infection triggers systemic transport of endogenous RNAs between shoots and roots in soybean显示文摘Legumes have evolved a symbiotic relationship with rhizobial bacteria and their roots form unique nitrogen-fixing organs called nodules.Studies have shown that abiotic and biotic stresses alter the profile of gene expression and transcript mobility in plants.However,little is known about the systemic transport of RNA between roots and shoots in response to rhizobial infection on a genome-wide scale during the formation of legume-rhizobia symbiosis.In our study,we found that two soybean(Glycine max)cultivars,Peking and Williams,show a high frequency of single nucleotide polymorphisms;this allowed us to characterize the origin and mobility of transcripts in hetero-grafts of these two cultivars.We identified 4,552 genes that produce mobile RNAs in soybean,and found that rhizobial infection triggers mass transport of m RNAs between shoots and roots at the early stage of nodulation.The majority of these mRNAs are of relatively low abundance and their transport occurs in a selective manner in soybean plants.Notably,the mRNAs that moved from shoots to roots at the early stage of nodulation were enriched in many nodule-related responsive processes.Moreover,the transcripts of many known symbiosis-related genes that are induced by rhizobial infection can move between shoots and roots.Our findings provide a deeper understanding of endogenous RNA transport in legume-rhizobia symbiotic processes. | Chen Zhang Meifang Qi Xiaxia Zhang Qi Wang Yanjun Yu Yijing Zhang Zhaosheng Kong | 2020 | Science China(Life Sciences)2020，63，8： | 2 |
| 12 | High levels of arbuscular mycorrhizal fungus colonization on Medicago truncatula reduces plant suitability as a host for pea aphids (Acyrthosiphon pisum)显示文摘This study sheds light on a poorly understood area in insect-plant-microbe interactions,focusing on aphid probing and feeding behavior on plants with varying levels of arbuscular mycorrhizal(AM)fungus root colonization.It investigates a commonly occurring interaction of three species:pea aphid Acyrthosiphon pisum,barrel medic Medicago truncatula,and the AM fungus Rhizophagus irregularis,examining whether aphid-feeding behavior changes when insects feed on plants at different levels of AM fungus colonization(42% and 84% root length colonized).Aphid probing and feeding behavior was monitored throughout 8 h of recording using the electrical penetration graph(EPG)technique,also,foliar nutrient content and plant growth were measured.Summarizing,aphids took longer to reach their 1st sustained phloem ingestion on the 84% AM plants than on the 42% AM plants or on controls.Less aphids showed phloem ingestion on the 84% AM plants relative to the 42% AM plants.Shoots of the 84% AM plants had higher percent carbon(43.7%)relative to controls(40.5%),and the 84% AM plants had reduced percent nitrogen(5.3%)relative to the 42% AM plants(6%).In conclusion,EPG and foliar nutrient data support the hypothesis that modifications in plant anatomy(e.g.,thicker leaves),and poor food quality(reduced nitrogen)in the 84% AM plants contribute to reduced aphid success in locating phloem and ultimately to differences in phloem sap ingestion.This work suggests that M.truncatula plants benefit from AM symbiosis not only because of increased nutrient uptake but also because of reduced susceptibility to aphids. | Elisa Garzo Eric Rizzo Alberto Fereres S.Karen Gomez | 2020 | Insect Science2020，27，1： | 1 |
| 13 | An MAP kinase interacts with LHK1 and regulates nodule organogenesis in Lotus japonicus显示文摘Symbiosis receptor-like kinase(SymRK) is a key protein mediating the legume-Rhizobium symbiosis.Our previous work has identified an MAP kinase kinase,SIP2,as a SymRK-interacting protein to positively regulate nodule organogenesis in Lotus japonicus,suggesting that an MAPK cascade might be involved in Rhizobium-legume symbiosis.In this study,LjMPK6 was identified as a phosphorylation target of SIP2.Stable transgenic L.japonicus with RNAi silencing of LjMPK6 decreased the numbers of nodule primordia(NP) and nodule,while plants overexpressing LjMPK6 increased the numbers of nodule,infection threads(ITs),and NP,indicating that LjMPK6 plays a positive role in nodulation.LjMPK6 could interact with a cytokinin receptor,LHK1 both in vivo and in vitro.LjMPK6 was shown to compete with LHP1 to bind to the receiver domain(RD) of LHK1 and to downregulate the expression of two LjACS(1-aminocyclopropane-1-carboxylic acid synthase) genes and ethylene levels during nodulation.This study demonstrated an important role of LjMPK6 in regulation of nodule organogenesis and ethylene production in L.japonicus. | Jun Yin Xiaomin Guan Heng Zhang Longxiang Wang Hao Li Qing Zhang Tao Chen Zeyuan Xu Zonglie Hong Yangrong Cao Zhongming Zhang | 2019 | Science China(Life Sciences)2019，62，9： | 1 |
| 14 | 赤水河流域地理环境与文化共生探析(英文)显示文摘This paper took Chishui River Basin as the research object,and pointed out that its culture,which reflected local life and production and was featured with regional characteristics as well as abundant cultural connotation,was constituted by native natural and cultural geography,folk customs and historical feature.The relation between Chishui salt path and salt business culture under the typical closed and half-closed geographical environment was analyzed to indicate that the realignment of Chishui River had brought prosperity of Chishui River,booming of commercial towns,and development of ancient architectures and guild hall culture.The relation between rich natural resources and production and life culture of Chishui River was explained to show that Danxia landform nurtured stone culture,Chishui River resources cultivated fishing culture,special hydrogeological environment fostered liquor culture represented by Maotai,and Bamboo culture accumulated for hundreds of years.Finally,it introduced military culture and the spirit of the Long March forming based on the special location of Chishui River.It emphasized that geological environment was the important basis for human's survival and played an immeasurable role in the cultural development of a region. | 王爱华 彭恩 | 2011 | Journal of Landscape Research2011，3，11： | 1 |
| 15 | STABILITY ANALYSIS OF A LOTKA-VOLTERRA COMMENSAL SYMBIOSIS MODEL INVOLVING ALLEE EFFECT显示文摘In this paper, we present a stability analysis of a Lotka-Volterra commensal symbiosis model subject to Allee effect on the unaffected population which occurs at low population density. By analyzing the Jacobian matrix about the positive equilibrium, we show that the positive equilibrium is locally asymptotically stable. By applying the differential inequality theory, we show that the system is permanent, consequently, the boundary equilibria of the system is unstable. Finally, by using the Dulac criterion, we show that the positive equilibrium is globally stable. Although Allee effect has no influence on the final densities of the predator and prey species, numeric simulations show that the system subject to an Allee effect takes much longer time to reach its stable steady-state solution, in this sense that Allee effect has unstable effect on the system, however, such an effect is controllable. Such an finding is greatly different to that of the predator-prey model. | Xinyu Guan | 2018 | Annals of Applied Mathematics2018，34，4： | 1 |
| 16 | Changes in gas exchange,root growth,and biomass accumulation of Platycladus orientalis seedlings colonized by Serendipita indica显示文摘Serendipita indica(formerly known as Piriformospora indica),a root endophytic fungus,exhibits multiple functions in some agricultural,horticultural,and medicinal plant species.We studied colonization of the roots of Platycladus orientalis,a forest tree species,by S.indica to improve the quality of the seedlings in seedbeds and survival rates in sylviculture.At 20 days after inoculation,S.indica colonized the root cortex of P.orientalis seedlings.Root colonization by S.indica significantly increased net CO2 assimilation,light use efficiency,and biomass accumulation by both roots and shoots,whereas it did not affect the biomass allocation between roots and shoots.In addition,the symbiosis significantly increased root total length,surface area,and volume.In view of the two specific traits of S.indica,i.e.,axenic culture and wide colonization in plants,the fungus might be used for improving quality of P.orientalis seedlings and increasing their survival after transplanting. | Chu Wu Qiao Wei Jing Deng Wenying Zhang | 2019 | Journal of Forestry Research2019，30，4： | 1 |
| 17 | Plasticity of mycangia in Xylosandrus ambrosia beetles显示文摘Insects that depend on microbial mutualists evolved a variety of organs to transport the microsymbionts while dispersing. The ontogeny and variability of such organs is rarely studied, and the microsymbiont*s effects on the animal tissue development remain unknown in most cases. Ambrosia beetles (Coleoptera: Curculionidae: Scolytinae or Platypodinae) and their mutualistic fungi are an ideal system to study the animalfungus interactions. While the interspecific diversity of their fungus transport organ一 mycangia—is well-known, their developmental plasticity has been poorly described. To determine the ontogeny of the mycangium and the influence of the symbiotic fungus on the tissue development, we dissected by hand or scanned with micro-CT the mycangia in various developmental stages in five Xylosandrus ambrosia beetle species that possess a large, mesonotal mycangium: Xylosandrus amputatus. Xylosandrus compactus, Xylosandrus crassiusculus, Xylosandrus discolor, and Xylosandrus germanus. We processed 181 beetle samples from the United States and China. All five species displayed three stages of the mycangium development:(1) young teneral adults had an empty, deflated and cryptic mycangium without fungal mass;(2) in fully mature adults during dispersal, the promesonotal membrane was inflated, and most individuals developed a mycangium mostly filled with the symbiont, though size and symmetry varied;and (3) after successful establishment of their new galleries, most females discharged the bulk of the fun gal inoculum and deflated the mycangium. Experimental aposymbiotic individuals demonstrated that the pronotal membrane invaginated independently of the presence of the fungus, but the fungus was required for inflation. Mycangia are more dynamic than previously thought, and their morphological changes correspond to the phases of the symbiosis. Importantly, studies of the fungal symbionts or plant pathogen transmission in ambrosia beetles need to consider which developmental stage to sample. We provide illustrations of the different stages, including microphotography of dissections and micro-CT scans. | You Li Yong-Ying Ruan Edward L. Stanley James Skelton Jiri Hulcr | 2019 | Insect Science2019，26，4： | 1 |
| 18 | Interaction between Earthworms and Arbuscular Mycorrhizal Fungi in Plants:A Review显示文摘Different kinds of soil animals and microorganisms inhabit the plant rhizosphere,which function closely to plant roots.Of them,arbuscular mycorrhizal fungi(AMF)and earthworms play a critical role in sustaining the soilplant health.Earthworms and AMF belong to the soil community and are soil beneficial organisms at different trophic levels.Both of them improve soil fertility and structural development,collectively promoting plant growth and nutrient acquisition capacity.Earthworm activities redistribute mycorrhizal fungi spores and give diversified effects on root mycorrhizal fungal colonization.Dual inoculation with both earthworms and AMF strongly magnifies the response on plant growth through increased soil enzyme activities and changes in soil nutrient availability,collectively mitigating the negative effects of heavy metal pollution in plants and soils.This thus enhances phytoremediation and plant disease resistance.This review simply outlines the effects of earthworms and AMF on the soil-plant relationship.The effects of earthworms on root AMF colonization and activities are also analyzed.This paper also summarizes the interaction between earthworms and AMF on plants along with suggested future research. | Lulu Meng A.K.Srivastava Kamil Kuča Bhoopander Giri Mohammed Mahabubur Rahman Qiangsheng Wu | 2021 | Phyton-International Journal of Experimental Botany2021，90，3： | 1 |
| 19 | Selection of rhizobial strains differing in their nodulation kinetics under low temperature in four temperate legume species显示文摘Background:Winter climate change including frequent freeze-thaw episodes and shallow snow cover will have major impacts on the spring regrowth of perennial crops.Non-bloating perennial forage legume species including sainfoin,birdsfoot trefoil,red clover,and alsike clover have been bred for their adaptation to harsh winter conditions.In parallel,the selection of cold-tolerant rhizobial strains could allow earlier symbiotic nitrogen(N)fixation to hasten spring regrowth of legumes.Methods:To identify strains forming nodules rapidly and showing high N-fixing potential,60 rhizobial strains in association with four temperate legume species were evaluated over 11 weeks under spring soil temperatures for kinetics of nodule formation,nitrogenase activity,and host yield.Results:Strains differed in their capacity to form efficient nodules on legume hosts over time.Strains showing higher nitrogenase activity were arctic strain N10 with sainfoin and strain L2 with birdsfoot trefoil.For clovers,nitrogenase activity was similar for control and inoculated plants,likely due to formation of effective nodules in controls by endophyte rhizobia present in seeds.Conclusions:Selection based on nodulation kinetics at low temperature,nitrogenase activity,and yield was effective to identify performant rhizobial strains for legume crops.The use of cold-tolerant strains could help mitigate winter climatic changes. | Emmanuelle D'Amours Annick Bertrand Jean Cloutier François-Philippe Chalifour Annie Claessens Solen Rocher Marie Bipfubusa Chantal Giroux Chantal J.Beauchamp | 2023 | Grassland Research2023，2，3： | 0 |
| 20 | Cloning and Sequencing of a 3.7kb Enhancing Fragment from Rhizobium fredii B52显示文摘The cosmid gene library of Rhizobium fredii strain B52 genome was constructed,andthen a 3.7kb enhancing fragment was isolated through plant experiment,which could im-prove the symbiotic efficiency of Bradyrhizobium japonicum strain 2210.The obtained higheffective strain was called HN32.It has been widely used as soybean inoculant in He-longjiang,Sichuan and Guangxi provinces with an average of 6%yield increase comparingwith 2210.The recombinant plasmid pHN32 in strain HN32 contains a 3.7kb foreign insert.Its nucleotide sequence was analyzed.Computer analysis indicated that there were two openreading frames(ORFs)within the 3.7kb enhancing fragment.ORF1 shows no homologywith known genes except the first 19 amino acids which had high homology with lactosetransferase of Agrobacterium radiobacter.ORF2 shows 54% homology with hupE of Rhizo-bium leguminosarum,and related with glycosylation transfer gene of Rhizobium meliloti.Names enfA and enfB are proposed to ORF1 and ORF2 respectively. | 张学贤 | 1996 | High Technology Letters1996，2，2： | 0 |
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