Is retinoic acid a signal for nerve regeneration in insects?

Until quite recently the retinoic acid （RA） signaling pathway was believed to occur only in vertebrates, but in the last decade, several ground-breaking studies have shown that it also exists in invertebrates. These include the discovery of endogenous retinoids （Nowickyj et al., 2008）, of retinoid receptor orthologs in insects （Hayward et al., 1999） and the very specific effect of RA on axonal guidance in the fresh water snail Lymnaea stagnalis （Dmetrichuk et al., 2008）. Despite some earlier indications of RA-dependent gene activation in insects, these papers really started retinoid research in invertebrates.

Apple whole genome sequences:recent advances and new prospects

In 2010,a major scientific milestone was achieved for tree fruit crops:publication of the first draft whole genome sequence(WGS)for apple(Malus domestica).This WGS,v1.0,was valuable as the initial reference for sequence information,fine mapping,gene discovery,variant discovery,and tool development.A new,high quality apple WGS,GDDH13 v1.1,was released in 2017 and now serves as the reference genome for apple.Over the past decade,these apple WGSs have had an enormous impact on our understanding of apple biological functioning,trait physiology and inheritance,leading to practical applications for improving this highly valued crop.Causal gene identities for phenotypes of fundamental and practical interest can today be discovered much more rapidly.Genome-wide polymorphisms at high genetic resolution are screened efficiently over hundreds to thousands of individuals with new insights into genetic relationships and pedigrees.High-density genetic maps are constructed efficiently and quantitative trait loci for valuable traits are readily associated with positional candidate genes and/or converted into diagnostic tests for breeders.We understand the species,geographical,and genomic origins of domesticated apple more precisely,as well as its relationship to wild relatives.The WGS has turbo-charged application of these classical research steps to crop improvement and drives innovative methods to achieve more durable,environmentally sound,productive,and consumer-desirable apple production.This review includes examples of basic and practical breakthroughs and challenges in using the apple WGSs.Recommendations for“what’s next”focus on necessary upgrades to the genome sequence data pool,as well as for use of the data,to reach new frontiers in genomics-based scientific understanding of apple.

Mangrove derived fungal endophytes–a chemical and biological perception

The potential of mangrove-derived endophytic fungi as a promising source of diverse and structurally unprecedented bioactive natural products is unquestionable and continues to attract considerable attention.This review highlights new bioactive mangrove fungal metabolites and known compounds with hitherto unreported biological activities described during the last 10 years.The compounds are categorized according to their reported biological activities,including cytotoxic,anti-infective,in addition to a wide range of miscellaneous activities such as protein kinase,αglucosidase,acetylcholinesterase and tyrosinase inhibitory activities,as well as antiangiogenic and neovascularisation effects,radical scavenging,DNA-binding affinity,and calcium and potassium channel blocking activity.

Fur glowing under ultraviolet:in situ analysis of porphyrin accumulation in the skin appendages of mammals

Examples of photoluminescence(PL)are being reported with increasing frequency in a wide range of organisms from diverse ecosystems.However,the chemical basis of this PL remains poorly defined,and our understanding of its potential ecological function is still superficial.Among mammals,recent analyses have identified free-base por-phyrins as the compounds responsible for the reddish ultraviolet-induced photoluminescence(UV-PL)observed in the pelage of springhares and hedgehogs.However,the localization of the pigments within the hair largely remains to be determined.Here,we use photoluminescence multispectral imaging emission and excitation spec-troscopy to detect,map,and characterize porphyrinic compounds in skin appendages in situ.We also document new cases of mammalian UV-PL caused by free-base porphyrins in distantly related species.Spatial distribution of the UV-PL is strongly suggestive of an endogenous origin of the porphyrinic compounds.We argue that reddish UV-PL is predominantly observed in crepuscular and nocturnal mammals because porphyrins are photodegradable.Con-sequently,this phenomenon may not have a specific function in intra-or interspecific communication but rather represents a byproduct of potentially widespread physiological processes.

柑橘天然生物活性物质吖啶酮的研究与利用

吖啶酮生物碱是一类重要的生物活性物质,芸香科柑橘类植物是天然吖啶酮的主要来源。至今已从柑橘类植物中分离得到20多种吖啶酮生物碱,它们在抗癌、抗肿瘤、抗病毒、抗疟疾和抗白血病等方面有重要作用。我国柑橘资源丰富,利用我国乃至世界丰富的柑橘资源对柑橘吖啶酮的开发利用前景广阔。对柑橘吖啶酮的已有研究多以根茎为实验材料,关于果实中吖啶酮的研究尚无报道。阐述了柑橘吖啶酮的结构特点、生理活性、生物合成和研究进展情况,并提出了植物天然吖啶酮的研究现状和形势,同时指明了在柑橘吖啶酮研究领域存在的问题及今后在此领域的研究重点和方向。

The Soil-Borne Identity and Microbiome-Assisted Agriculture:Looking Back to the Future

Looking forward includes looking back every now and then.In 2007,David Weller looked back at 30 years of biocontrol of soil-borne pathogens by Pseudomonas and signified that the progress made over decades of research has provided a firm foundation to formulate current and future research questions.It has been recognized for more than a century that soil-borne microbes play a significant role in plant growth and health.The recent application of high-throughput omics technologies has enabled detailed dissection of the microbial players and molecular mechanisms involved in the complex interactions in plant-associated microbiomes.Here,we highlight old and emerging plant microbiome concepts related to plant disease control,and address perspectives that modern and emerging microbiomics technologies can bring to functionally characterize and exploit plant-associated microbiomes for the benefit of plant health in future microbiome-assisted agriculture.

Microplastic fiber and drought effects on plants and soil are only slightly modified by arbuscular mycorrhizal fungi

Microplastics are increasingly recognized as a factor of global change. By altering soil inherentproperties and processes, ripple-on effects on plants and their symbionts can be expected.Additionally, interactions with other factors of global change, such as drought, can influence theeffect of microplastics. We designed a greenhouse study to examine effects of polyester microfibers,arbuscular mycorrhizal (AM) fungi and drought on plant, microbial and soil responses. We found thatpolyester microfibers increased the aboveground biomass of Allium cepa under well-watered anddrought conditions, but under drought conditions the AM fungal-only treatment reached the highestbiomass. Colonization with AM fungi increased under microfiber contamination, however, plantbiomass did not increase when both AM fungi and fibers were present. The mean weight diameter ofsoil aggregates increased with AM fungal inoculation overall but decreased when the system wascontaminated with microfibers or drought stressed. Our study adds additional support to themounting evidence that microplastic fibers in soil can affect the plant–soil system by promoting plantgrowth, and favoring key root symbionts, AM fungi. Although soil aggregation is usually positivelyinfluenced by plant roots and AM fungi, and microplastic promotes both, our results show that plasticstill had a negative effect on soil aggregates. Even though there are concerns that microplastic mightinteract with other factors of global change, our study revealed no such effect for drought.

Influence of experimental soil disturbances on the diversity of plants in agricultural grasslands

Aims and Methods Disturbance is supposed to play an important role for biodiversity and ecosystem stability as described by the intermediate disturbance hypoth-esis(IDH),which predicts highest species richness at intermediate levels of disturbances.In this study,we tested the effects of artificial soil distur-bances on diversity of annual and perennial vascular plants and bryo-phytes in a field experiment in 86 agricultural grasslands differing in land use in two regions of Germany.On each grassland,we implemented four treatments:three treatments differing in application time of soil dis-turbances and one control.One year after experimental disturbance,we recorded vegetation and measured biomass productivity and bare ground.We analysed the disturbance response taking effects of region and land-use-accompanied disturbance regimes into account.Important Findings Region and land-use type strongly determined plant species rich-ness.Experimental disturbances had small positive effects on the species richness of annuals,but none on perennials or bryophytes.Bare ground was positively related to species richness of bryophytes.However,exceeding the creation of 12%bare ground further distur-bance had a detrimental effect on bryophyte species richness,which corresponds to the IDH.As biomass productivity was unaffected by disturbance our results indicate that the disturbance effect on spe-cies richness of annuals was not due to decreased overall produc-tivity,but rather due to short-term lowered inter-and intraspecific competition at the newly created microsites.Generally,our results highlight the importance of soil disturbances for species richness of annual plants and bryophytes in agricultural grasslands.However,most grasslands were disturbed naturally or by land-use practices and our additional experimental soil dis-turbances only had a small short-term effect.Overall,total plant diversity in grasslands seemed to be more limited by the availabil-ity of propagules rather than by suitable microsites for germination.Thus,nature conservation efforts to increase grassland diversity should focus on overcoming propagule limitation,for instance by additional sowing of seeds,while the creation of additional open patches by disturbance might only be appropriate where natural disturbances are scarce.

The stability of carbon from a maize-derived hydrochar as a function of fractionation and hydrothermal carbonization temperature in a Podzol

Hydrochar(HC)produced by the hydrothermal carbonization(HTC)of typically wet biomass is generally considered to be less effective for carbon(C)sequestration in soils compared to biochar(BC)by pyrolysis,due to a higher content of more easily decomposable C.Although the recalcitrance of HC is suggested to improve with increasing HTC production temperature,the way it interacts and becomes associated with soil organic matter(SOM)fractions of different stabilities against decomposition,may also influence its effectiveness for C sequestration in soils.In that respect,this study aimed to verify the potential of HCs from maize silage produced at different HTC temperatures(190,210 and 230℃)for C sequestration in a HC-amended sandy loam Podzol.To do this,we conducted a pot trial experiment and traced the fate of HC-derived C(HC-C)within different SOM fractions,namely the free-and occluded particulate organic matter(POMF and POMO,respectively)fractions and that comprising organic matter(OM)bound to clays(OMCl).Approx.1 year after applying 5%of the different HTC temperature HCs to the soil,the SOM fractions were isolated by density fractionation for each HC treatment(HC190,HC210 and HC230)and the control(absent of HC).All fractions and the HCs were analyzed for organic C(OC)content and isotopic signatures(δ^(13)C).From the δ^(13)C signatures,the amount of HC-C and native soil organic carbon(SOC)within each fraction was calculated.Increased C contents and decreased H/C and O/C ratios were observed with increasing HTC production temperatures,which sug-gests a lower stability for the low temperature HC.After ca.1 year,a loss of~20-23%of the bulk soil TOC was found in the HC-amended soils.The POMF fraction of the HC-amended soils showed losses of 68-81%HC-C and 52-72%native SOC,which may be due to a positive priming effect caused by HC addition.The POM_(O) and OM_(Cl) fractions of the HC-amended soils contained more OC than the control,indicating the integration of HC-C together with SOM within these more stable fractions,while the effect of HTC production temperature on the level of decomposition of the resultant HCs was negligible.In all HC treatments,the OM_(Cl) fraction comprised the least amount of HC-C,thus showing the weakest response to C amendment.In conclusion,long(er)-term research on the C net balance that accounts for the observed priming-induced TOC losses and the HC-C enrichment in more stable fractions is required to verify the potential of the different HCs for the purpose of C sequestration in soils.

Additive effects of functionally dissimilar above- and belowground organisms on a grassland plant community

In nature,plant communities are affected simultaneously by a variety of functionally dissimilar organisms both above and below the ground.However,there is a gap of knowledge on interactive effects of functionally dissimilar organisms on plant communities that is needed to be filled to better understand and predict the general impact of biotic factors on plant communities.Methods We conducted a full-factorial mesocosm study to investigate the individual and combined impacts of above-and belowground functionally dissimilar organisms on a grassland plant community.We studied the effects of aboveground herbivores(Helix aspersa,Gastropoda),arbuscular mycorrhizal fungi(AMF;Glomus spp.,Glomeromycota)and endogeic earthworms(Aporrectodea spp.,Lumbricidae)on the diversity,structure and productivity of an experimental grassland plant community and each other.Important Findings Aboveground herbivory by snails decreased,AMF increased and earthworms had no effects on the diversity of the grassland plant community,while their combined effects were additive.The biomass of the plant community was negatively affected by snails and AMF,while no effects of earthworms or interaction effects were found.The plant species were differently affected by snails and AMF.No effects of the above-and belowground organisms on each other’s performance were detected.Since the effects of the functionally dissimilar organisms on the grassland plant community were mainly independent,the results indicate that their combined effects may be predicted by knowing the individual effects,at least under the conditions used in the present mesocosm study.

Endophytes and associated marine derived fungi—ecological and chemical perspectives

The potential of endophytes and algal or invertebrate associated marine derived fungi as promising sources of structurally unprecedented bioactive natural products is undeniable and continues to attract broad attention.This review highlights new bioactive fungal metabolites reported in 2011 until April 2012,as well as known compounds for which novel biological activities have been disclosed.All compounds are grouped according to their reported biological activities which include cytotoxic,anti-infective,as well as radical scavenging,enzyme inhibition,anti-fouling and anti-parasitic activities.Overall,178 fungal metabolites,including 138 new natural products are presented.Furthermore,new insights into fungal-host interaction,chemical communication,and chemo-ecological roles of fungal metabolites,as well as new strategies for bioprospecting are presented.

An investigation of the effects of hydrochar application rate on soil amelioration and plant growth in three diverse soils

The hydrothermal carbonization(HTC)of biogas digestate alters the raw materials inherent characteristics to produce a carbon(C)-rich hydrochar(HC),with an improved suitability for soil amelioration.Numerous studies report conflicting impacts of various HC application rates on soil properties and plant growth.In this study,the influence of HC application rate on soil improvement and plant growth aspects was investigated in three diverse soils(Chernozem,Podzol,and Gleysol).Pot trials were conducted in which all soils were amended with 5,10,20 and 30%(w/w)HC in quintuplicate,with two controls of pure soil(with and without plants,respectively)also included.Prior to potting,soil samples were collected from all HC-amended soils and controls and analyzed for soil pH,plant available nutrients(PO4-P and K),and microbial activity using standard laboratory and statistical methods.Immediately after potting,a 6-week seed germination experiment using Chinese cabbage was conducted to determine germination success,followed by a plant growth experiment of equal duration and plant species to determine biomass success.At the end of the study(after a total plant growth period of 12 weeks),each pot was sampled and comparatively analyzed for the same soil properties as at the beginning of the study.Soil pH shifted toward the pH of the HC(6.6)in all soils over the course of the study,but was most expressed in the 20%and 30%application rates,confirming the well-documented liming effect of HC.The addition of HC increased the PO4-P and K contents,particularly with 20%and 30%HC amendments.These results are proposedly due to the large labile C fraction of the HC,which is easily degradable by microorganisms.The rapid decomposition of this C fraction prompted the quick release of the HCs inherently high PO4-P and K content into the soil,and in turn,further stimulated microbial activity,until this fraction was essentially depleted.HC addition did not inhibit seed germination at any rate,presumably due to a lack of phytotoxic compounds in the HC from aging and microbial processes,and furthermore,showed no significant impact(positive or negative)on plant growth in any soil,despite improved soil conditions.In conclusion,although less pronounced,soil improvements were still achievable and maintainable at lower application rates(5%and 10%),whereas higher rates did not ensure greater benefits for plant growth.While the addition of high rates of HC did not detrimentally effect soil quality or plant growth,it could lead to leaching if the nutrient supply exceeds plant requirements and the soil’s nutrient retention capacity.Therefore,this study validates the previous study in the effectiveness of the biogas digestate HC for soil amelioration and suggests that smaller regularly repeated HC applications may be recommendable for soil improvement.

Tricarbocyclic core formation of tyrosine-decahydrofluorenes implies a three-enzyme cascade with XenF-mediated sigmatropic rearrangement as a prerequisite

Tyrosine-decahydrofluorene derivatives feature a fused[6.5.6]tricarbocyclic core and a 13-membered para-cyclophane ether.Herein,we identified new xenoacremones A,B,and C(1-3)from the fungal strain Xenoacremonium sinensis ML-31 and elucidated their biosynthetic pathway using gene deletion in the native strain and heterologous expression in Aspergillus nidulans.The hybrid polyketide synthaseenonribosomal peptide synthetase(PKS-NRPS)XenE together with enoyl reductase XenG were confirmed to be responsible for the formation of the tyrosine-nonaketide skeleton.This skeleton was subsequently dehydrated by XenA to afford a pyrrolidinone moiety.XenF catalyzed a novel sigmatropic rearrangement to yield a key cyclohexane intermediate as a prerequisite for the formation of the multi-ring system.Subsequent oxidation catalyzed by XenD supplied the substrate for XenC to link the para-cyclophane ether,which underwent subsequent spontaneous Diels-Alder reaction to give the end products.Thus,the results indicated that three novel enzymes XenF,XenD,and XenC coordinate to assemble the[6.5.6]tricarbocyclic ring and para-cyclophane ether during biosynthesis of complex tyrosine-decahydrofluorene derivatives.

The influence of hydrochar from biogas digestate on soil improvement and plant growth aspects

Hydrochar(HC),produced by hydrothermal carbonization,offers technical advantages over biochar(BC)produced by pyrolysis,and is suitable for soil amelioration,carbon sequestration,and enhanced plant growth.BC grain size has been shown to influence nutrient retention,microbial colonization and aggregate formation;however,similar research for HC is lacking.Pot trials were conducted to investigate the influence of HC grain size[coarse(6.3-2 mm),medium(2-0.63 mm)and fine(<0.63 mm)],produced from biogas digestate,for soil improvement in three soils:loamy Chernozem,sandy Podzol,and clayey Gleysol,at a 5%HC application rate(w/w).All soils including two controls(with and without plants)were analysed for water holding capacity(WHC),cation exchange capacity(CEC),wet aggregate stability,pH,plant available nutrients(PO_(4)-P,K and N_(min))and germination and biomass success using standard laboratory and statistical methods.Soil pH showed a compensatory shift toward the HC pH(7.2)in all soils over the course of the study.For example,the pH of the medium grained HC treatment for the Chernozem decreased from 7.9 to 7.2 and increased in the Podzol and Gleysol from 5.9 to 6.1 and 4.9 to 5.5,respectively.The nutrient-rich HC(2034±38.3 mg kg^(−1) PO_(4)-P and 2612.5±268.7 mg kg^(−1) K content)provided only a short-term supply of nutrients,due to the relatively easily mineralized fraction of HC,which allowed for quick nutrient release.The pH and PO_(4)-P effects were most pronounced in the fine grained HC treatments,with a~87%,~308%and~2500%increase in PO_(4)-P content in the Chernozem,Podzol and Gleysol,respectively,compared to the controls at the beginning of the study.The same trend was observed for the K and NH_(4)^(+)content in the fine and medium grained HC treatments in all soils.No seed germination inhibition of Chinese cabbage was observed,with average germina-tion rates>50%in all soils.An effect on NO_(3)^(−)content was indeterminable,while there was little to no effect on biomass production,WHC,CEC and aggregate stability.In conclusion,the application of 5%fine grained HC significantly influenced the nutrient content over a short-term.However,the application rate was insufficient to substantially improve plant growth,nor to sustain a longer-term nutrients supply,regardless of grain size.

Naming and outline of Dothideomycetes-2014 including proposals for the protection or suppression of generic names

Article 59.1,of the International Code of Nomenclature for Algae,Fungi,and Plants(ICN;Melbourne Code),which addresses the nomenclature of pleomorphic fungi,became effective from 30 July 2011.Since that date,each fungal species can have one nomenclaturally correct name in a particular classification.All other previously used names for this species will be considered as synonyms.The older generic epithet takes priority over the younger name.Any widely used younger names proposed for use,must comply with Art.57.2 and their usage should be approved by the Nomenclature Committee for Fungi(NCF).In this paper,we list all genera currently accepted by us in Dothideomycetes(belonging to 23 orders and 110 families),including pleomorphic and nonpleomorphic genera.In the case of pleomorphic genera,we follow the rulings of the current ICN and propose single generic names for future usage.The taxonomic placements of 1261 genera are listed as an outline.Protected names and suppressed names for 34 pleomorphic genera are listed separately.Notes and justifications are provided for possible proposed names after the list of genera.Notes are also provided on recent advances in our understanding of asexual and sexual morph linkages in Dothideomycetes.A phylogenetic tree based on four gene analyses supported 23 orders and 75 families,while 35 families still lack molecular data.

Contrasting soil fungal communities in Mediterranean pine forests subjected to different wildfire frequencies

Mediterranean forest ecosystems are characterized by various vascular plant groups with their associated mycor-rhizae and free living soil fungi with various ecological functions.Fire plays a major role in Mediterranean ecosystem dynamics and impacts both above-and below-ground community structure and functioning.However,studies on the effects induced by altered disturbance regimes(associated with recent land use and climate extremes)on fire ecology and especially on its below-ground impacts are few.The objectives of this study were to evaluate the effects of different wildfire regimes on soil fungal community structure using two different molecular methods.We investigated the long-term effects of wildfire on soil fungal communities associated with Pinus pinaster forests in central Portugal,by comparing the results of denaturing gradient gel electrophoresis(DGGE)-based profiling with those obtained with 454 pyrosequencing.Four forest stands with differing fire history and fire return interval,and vegetation cover(mature forest,early successional stage of pine regeneration,and forest converted to scrubland)were sampled 6 years after the last fire event.The pyrosequencing-based approach indicated ca.eight-fold higher numbers of taxa than DGGE.However,fungal community fingerprinting data obtained for the different study stands with DGGE were congruent with those obtained with pyrosequencing.Both short(7.6 years)and long(24 years)fire return intervals(indicated by the presence of ericaceous shrubs in the understorey)induced a decrease in the abun-dance ratio between basidiomycetes and ascomycetes and appeared to reduce the frequency of ectomycorrhizal fungal species and saprophytes.Wildfire significantly reduced the frequency of late stage successional taxa(e.g.Atheliaceae and Cantharellales)and known or putative saprophytes belonging to the Clavulinaceae and the Archaeorhizomycetaceae.Conversely,early successional fungal species belonging to the Thelephoraceae were favoured by both fire return inter-vals,while the abundance of Cortinarius and Hebeloma,which include several Cistus-specific species,increased with short wildfire return intervals.This last finding highlights the relationship between postfire vegetation composition and cover(vegetation successional stage),and fungal symbionts.We hypothesise that these changes could,in the long term,exhaust the resilience of Mediterranean pine forest vegetation and associated soil fungal communities by preventing pine regeneration.

Colorful Insights： Advances in Imaging Drive Nove 3reakthroughs in Ca^2＋ Signaling

In plants, Ca^2＋ signals occur in response to both environmental and developmental stimuli. These signals involve increases in [Ca^2＋] in compartments such as the cytoplasm, nucleus, and mitochondria, and can display multiple shapes ranging from sin- gle transients to repetitive Ca^2＋ oscillations. Generation and shaping of stimulus specific [Ca^2＋] signatures depends on Ca^2＋ influxes and effluxes occurring at both the plasma membrane （PM） and membranes of the different subcellular compartments.

Families of Dothideomycetes

Dothideomycetes comprise a highly diverse range of fungi characterized mainly by asci with two wall layers(bitunicate asci)and often with fissitunicate dehiscence.Many species are saprobes,with many asexual states comprising important plant pathogens.They are also endophytes,epiphytes,fungicolous,lichenized,or lichenicolous fungi.They occur in terrestrial,freshwater and marine habitats in almost every part of the world.We accept 105 families in Dothideomycetes with the new families Anteagloniaceae,Bambusicolaceae,Biatriosporaceae,Lichenoconiaceae,Muyocopronaceae,Paranectriellaceae,Roussoellaceae,Salsugineaceae,Seynesiopeltidaceae and Thyridariaceae introduced in this paper.Each family is provided with a description and notes,including asexual and asexual states,and if more than one genus is included,the type genus is also characterized.Each family is provided with at least one figure-plate,usually illustrating the type genus,a list of accepted genera,including asexual genera,and a key to these genera.A phylogenetic tree based on four gene combined analysis add support for 64 of the families and 22 orders,including the novel orders,Dyfrolomycetales,Lichenoconiales,Lichenotheliales,Monoblastiales,Natipusillales,Phaeotrichales and Strigulales.The paper is expected to provide a working document on Dothideomycetes which can be modified as new data comes to light.It is hoped that by illustrating types we provide stimulation and interest so that more work is carried out in this remarkable group of fungi.