Although the research on Cordaites of the Cathaysian Flora in China started early in 1883, the study of the cordaitean cuticles began late in 1991. Up to now, four types of cordaitean cuticles in situ and three types ...Although the research on Cordaites of the Cathaysian Flora in China started early in 1883, the study of the cordaitean cuticles began late in 1991. Up to now, four types of cordaitean cuticles in situ and three types of dispersed ones have been reported from the Cathaysian Flora in China. However compared with the Euramerican Flora, the research work on cordaitean cuticles from the Cathaysian Flora in China is much more insufficient. In this paper, three kinds of dispersed cordaitean cuticles are described in detail from the Permian coal-bearing strata in China. Among these cuticles two kinds are collected from the roof shale of Coal Seam No. A(1) in Shanxi Formation (Lower Permian) in Xinzhuangzhi Coal Mine of Huainan, Anhui Province, southern border of North China Subprovince of the Cathaysian Flora in China. The third one was collected from Coal Seam No. 11 in the top of Longtan Formation (lower Upper Permian) in Dahebian Coal Mine of Shuicheng Mining District, Guizhou Province, South China Subprovince of the Cathaysian Flora in China. Comparison of these three kinds of cordaitean cuticles with the known ones from the Cathaysian Flora in China and from the Euramerican Flora is made. The authors consider that they are all new types of cordaitean cuticles. The significance they bear on palaeobotany is discussed.展开更多
Coniopteris was a ubiquitous plant of the Jurassic and Cretaceous periods and played an important role in the flora of the time. However, its anatomical structure is relatively poorly known. The specimens of Coniopter...Coniopteris was a ubiquitous plant of the Jurassic and Cretaceous periods and played an important role in the flora of the time. However, its anatomical structure is relatively poorly known. The specimens of Coniopteris hymenophylloides(Brongniart) Seward described here were collected from the Yaojie Formation in Gansu Province, northwestern China. The sterile fronds are characterized as being at least bipinnate with alternate arranged linear pinnae covered by thin cuticles. Fertile fronds are linear-lanceolate, with single sorus at the margin of each fertile pinnule. In situ spores are typically trilete, triangle to subcircular in polar view, cap-shaped in equatorial view, and 37 μm in average diameter. The trilete marking is straight and narrow, generally extends to 4/5 of the spore radius. The spore surface is smooth, and parts of the exine are granulated. The epidermal cells of cuticles are irregular in shape, approximately 40-60μm long and 10-20 μm wide. The elliptical stomatal complexes are paracytic,approximately 30 μm long and 19 μm wide,and irregularly distributed. On the basis of its epidermal structures and comparisons with extant ferns, we consider that Coniopteris displays combined features of the related extant genera.展开更多
To better understand the interaction mechanisms of plant surfaces with polar organic compounds, sorption of 4-chlorophenol, 2,4- dichlorophenol, and 2,4,6-trichlorophenol by fruit cuticles （i.e., tomato, apple, and p...To better understand the interaction mechanisms of plant surfaces with polar organic compounds, sorption of 4-chlorophenol, 2,4- dichlorophenol, and 2,4,6-trichlorophenol by fruit cuticles （i.e., tomato, apple, and pepper）, and potato tuber periderm were investigated. The roles of cuticular components （waxes, cutin, cutan and sugar） on sorption of chlorophenols are quantitatively compared. Cutin and waxes govern the sorption capacity of bulk apple cuticle by hydrophobic interactions. Potato periderm with highest sugar content exhibits the lowest sorption capability for the chlorophenols. With the increase of hydrophobicity （i.e., Kow ） of sorbate, the relative contribution of lipophilic components （wax, cutin and cutan） on total sorption increases, however, the ratios of Koc to Kow decreases due to increasing ionization degree of sorbates.展开更多
We have developed a method where, after glutaraldehyde fixation, human hair shafts and insect cuticles are treated with ammonium thioglycolate (ATG) to improve ultrastructural staining. Conventional transmission elect...We have developed a method where, after glutaraldehyde fixation, human hair shafts and insect cuticles are treated with ammonium thioglycolate (ATG) to improve ultrastructural staining. Conventional transmission electron microscopic (TEM) preparations do not distinguish the A-layer and the exocuticles of hair shafts. However, after ATG treatment, the A-layer appears in higher contrast. ATG treatment has also been used to observe the fibrillar structure in the cortex. In the cuticle of beetles, the epicuticle is stained by ATG. Although the human hair shaft (keratin) and insect cuticle (chitin) are composed of different materials, both can be reduced by the ATG solution. The ammonium in the ATG solution reacts with hair shafts and insect cuticles, causing a reduction of swelled cuticles. Therefore, ATG not only stains, but also reduces human hair shafts and the cuticles of beetles.展开更多
After germination in the dark,plants produce a shoot apical hook and closed cotyledons to protect the quiescent shoot apical meristem(SAM),which is critical for seedling survival during skotomorphogenesis.The factors ...After germination in the dark,plants produce a shoot apical hook and closed cotyledons to protect the quiescent shoot apical meristem(SAM),which is critical for seedling survival during skotomorphogenesis.The factors that coordinate these processes,particularly SAM repression,remain enigmatic.Plant cuticles,multilayered structures of lipid components on the outermost surface of the aerial epidermis of all land plants,provide protection against desiccation and external environmental stresses.Whether and how cuticles regulate plant development are still unclear.Here,we demonstrate that mutants of BODYGUARD1(BDG1)and long-chain acyl-CoA synthetase2(LACS2),key genes involved in cutin biosynthesis,produce a short hypocotyl with an opened apical hook and cotyledons in which the SAM is activated during skotomorphogenesis.Light signaling represses expression of BDG1 and LACS2,as well as cutin biosynthesis.Transcriptome analysis revealed that cuticles are critical for skotomorphogenesis,particularly for the development and function of chloroplasts.Genetic and molecular analyses showed that decreased HOOKLESS1 expression results in apical hook opening in the mutants.When hypoxia-induced expression of LITTLE ZIPPER2 at the SAM promotes organ initiation in the mutants,the de-repressed expression of cell-cycle genes and the cytokinin response induce the growth of true leaves.Our results reveal previously unrecognized developmental functions of the plant cuticle during skotomorphogenesis and demonstrate a mechanism by which light initiates photomorphogenesis through dynamic regulation of cuticle synthesis to induce coordinated and systemic changes in organ development and growth during the skotomorphogenesis-to-photomorphogenesis transition.展开更多
Leaf cuticle analysis has long been a powerful tool for fossil plant identification,systematics,and palaeoclimatological recon-struction.In recent decades the application of stomatal frequency data that are relied on ...Leaf cuticle analysis has long been a powerful tool for fossil plant identification,systematics,and palaeoclimatological recon-struction.In recent decades the application of stomatal frequency data that are relied on precise calculation of stomata on plant fossil cuticles to reconstruct ancient atmospheric CO_(2)concentration made the preparation of cuticular membrane with sufficient size a critical technique in palaeoclimatological research.However,for plants with originally thin and fragile cuticles,e.g.,most deciduous plants,conventional techniques sometimes fail to obtain cuticular membranes with sufficient size,or sometimes unable to recover any.This has largely hampered the usage of fossil cuticle analysis in palaeobotanical and palaeo-climatological research.Here,we describe a new method using clear nail polish as a medium to"strengthen"the originally thin and fragile cuticles prior to maceration procedures.We demonstrate the method by using middle Eocene Metasequoia fossils that were notorious for the difficulty of recovering large-sized clean cuticular membranes due to their thin and fragile nature.Metasequoia,with well-documented and widely-distributed fossil records since the Late Cretaceous and with a living repre-sentative,114.glyptostroboides,as a comparative reference,bas been widely used as a model genus for the study of evolution of plants,palaeoclimatological reconstruction,and plant adaptation to climate changes.But its deciduous habit produces thin cuticles and makes the preparation of clean cuticular membranes a tedious process.The new method successfully allows us to recover its delicate cuticular membranes with sufficient sizes for SEM observation and stomatal frequency analysis.展开更多
Chitin is an abundant natural biopolymer that plays a crucial role in insect growth and development as a fundamental structural component of the exoskeleton.The membrane-integralβ-glycosyltransferase,chitin synthase,...Chitin is an abundant natural biopolymer that plays a crucial role in insect growth and development as a fundamental structural component of the exoskeleton.The membrane-integralβ-glycosyltransferase,chitin synthase,has been identified as the central component in chitin biosynthesis.However,the precise roles of other proteins in facilitating chitin synthase in chitin biosynthesis remain unclear.In this study,we employed split-ubiquitin membrane yeast two-hybrid(MYTH)and pull-down assays to demonstrate the physical interaction between Twinstar(Tsr),a small molecular protein in the actin-depolymerizing factor ADF/Cofilin protein family,and chitin synthase Krotzkopf verkehrt(Kkv)in Drosophila melanogaster in vitro.The RNA interference(RNAi)-mediated global knockdown of Tsr in D.melanogaster resulted in larval lethality.Furthermore,targeted suppression of Tsr in the tracheal and epidermal tissues also led to larval mortality,while knocking down Tsr in the wing tissues led to wrinkled wings.Additionally,silencing Tsr not only reduced the chitin content in the first longitudinal vein of the wings but also led to the absence of the chitin lamellar structure.To validate the functional conservation of Tsr in other insect orders,the two agricultural pests Ostrinia furnacalis and Tribolium castaneum,representing lepidoptera and coleoptera insects,respectively,were investigated.Knockdown experiments targeting the Drosophila Tsr orthologues OfTsr in O.furnacalis and TcTsr in T.castaneum produced abnormal larvae during molting or pupation in O.furnacalis and lethality in T.castaneum.Our findings not only improve ourknowledge of the chitin biosynthesis machinery in insect cuticles but also provide new potential targets for the control of major agricultural pests.展开更多
CRISPR/Cas9-based gene editing research has advanced greatly and shows broad potential for practical application in life sciences,but the Cas9 system is often constrained by the requirement of a protospacer adjacent m...CRISPR/Cas9-based gene editing research has advanced greatly and shows broad potential for practical application in life sciences,but the Cas9 system is often constrained by the requirement of a protospacer adjacent motif(PAM)at the target site.While xCas9,a variant derived from Streptococcus pyogenes Cas9(SpCas9),can recognize a broader range of PAMs,its application in non-model insects is lacking.In this study,we explored xCas9 activity in gene editing by selecting corazonin(Crz)and the target sites with various PAMs in Locusta migratoria,a destructive insect pest worldwide.We found that xCas9 could cleave the target site with AG PAM while SpCas9 could not,although xCas9 appeared to have lower activity than SpCas9 at the canonical NGG PAMs.The heritable homozygous Crz^(-/-)locust strain was generated by the application of xCas9.The Crz^(-/-)strain showed an albino body color,with significantly downregulated expression of several body color-related genes including Pale,Vermilion,Cinnabar,White andβ-carotene-binding protein.In addition,Crz^(-/-)mutants exhibited significantly reduced expression of Chitin synthase 1,along with a markedly lower chitin content as well as compact and rigid cuticles.Furthermore,Crz^(-/-)mutants displayed impaired performance under low-temperature stress,including prolonged lifespan,reduced body weight and smaller body size.Our results suggest that xCas9 is effective for insect genome editing,and Crz plays essential roles in insect body color,cuticle development and adaptation to low-temperature stress.The findings of this study extend the application of xCas9 in non-model insects and provide new insights into our understanding of the regulation of insect cuticle development and environmental adaptation.展开更多
Extreme environmental conditions such as temperature fluctuations,drought,and pathogen attacks can significantly impact plant growth,development,and productivity.Plants have evolved intricate enzymatic systems to miti...Extreme environmental conditions such as temperature fluctuations,drought,and pathogen attacks can significantly impact plant growth,development,and productivity.Plants have evolved intricate enzymatic systems to mitigate these stresses,among which GDSL esterase/lipase proteins (GELPs)-key members of the serine esterase/lipase superfamily-play important roles (Akoh et al.,2004).Characterized by a conserved GDSL motif and four essential amino acids (serine,glycine,asparagine,and histidine),GELPs exhibit versatile catalytic functions in lipid metabolism,cell wall modification,and stress responses (Ursache et al.,2021;Shen et al.,2022).展开更多
Devonian cutinitic liptobiolith is a special type of coal formed during the early evolutionary stage of land plants.The Baishaping and Damaidi Devonian coals are notable for their distinct papery,sheet-like texture,an...Devonian cutinitic liptobiolith is a special type of coal formed during the early evolutionary stage of land plants.The Baishaping and Damaidi Devonian coals are notable for their distinct papery,sheet-like texture,and unusually high cutinite content(>50%),belonging to typical cutinitic liptobiolith.They are bituminous coals and have a suppressed vitrinite reflectance.Compared with typical typeⅢkerogen,these liptobioliths are characterized by extremely high yields of volatile matter and high hydrogen contents owing to their enhanced cutinite contents.As indicated by pyrolysis and elemental analysis results,the Devonian cutinitic liptobioliths are dominated by typeⅠ-Ⅱkerogens and have an excellent potential to generate liquid hydrocarbons.The Baishaping cutinitic liptobioliths are mainly composed of ribbon-like thick-walled cutinites,with small amounts of thin-walled type.Vitrinite is only present in trace amounts and is dominated by telinite.Meanwhile,the Damaidi Devonian coals are primarily composed of ribbon-like thin-walled cutinites,followed by collotelinites which are usually sandwiched by cutinites.The different petrological characteristics of the Baishaping and Damaidi liptobioliths might indicate a structural variation in the coal-forming plant cuticles and two distinct coal-forming conditions.The molecular bio markers in the Devonian coals are mainly composed of C_(18)-C_(20)tetracyclic diterpenoids,which are assumed to be the dominant soluble constituent of the Devonian land-plant cuticles and might have played an important role in early land plant radiation.Other molecules include aromatic tetracyclic diterpenoids,3-5 ring polycyclic aromatic hydrocarbons and their methylated counterparts,and C_(16)-and C_(18)-monocarboxylic acids.n-Alkanes are present only in small amounts.The molecular composition of the cutinite-rich coals is unexpected,because cuticular waxes are one of the most important sources of n-alkanes.In general,the petrology and geochemistry of the Devonian cutinitic liptobiolith indicate a distinct structure and composition for the early land-plant cuticles,which is significantly different from that of the plant cuticles since Carboniferous.Devonian cutinitic liptobioliths are of great interest because of their unique petrography,geochemistry,coal-forming plants,and oil-prone potential.Studies on this unique coal type provide a better understanding of coal-forming plants,paleoenvironment,paleoclimate,and early land-plant evolution in the Devonian.展开更多
Two new species of Eretmophyllum Thomas are described from the lower(Toarcian)and upper(Aalenian)Prisayan Formation of the Irkutsk Basin,Eastern Siberia,Russia based on distinct morphological and cuticular features of...Two new species of Eretmophyllum Thomas are described from the lower(Toarcian)and upper(Aalenian)Prisayan Formation of the Irkutsk Basin,Eastern Siberia,Russia based on distinct morphological and cuticular features of the leaves that distinguish them from other species of the genus.Eretmophyllum polypapillosum sp.nov.is characterized by the presence of 2-3 papillae on the lower and upper epidermis of ordinary cells.Taphonomically,the leaf burials of E.polypapillosum sp.nov.indicate that it preferred mesophilic forests developed on river terraces and/or low watersheds.Eretmophyllum yershowskiensis sp.nov.is represented exclusively by leaf cuticles extracted by coal maceration,and it probably inhabited the low banks of peat bogs.The presence of the genus Eretmophyllum in the Early Jurassic of France and Eastern Siberia shows that it was already widespread in the territory of Eurasia,distributed from Western Europe to Eastern Siberia.This indicates the possible existence of Eretmophyllum species elsewhere in the Early Jurassic such as Central Asia and Northwest China.展开更多
Analysis, evaluation and statistics of dispersed cuticles, spores and wood pieces in Middle Devouian cutinitic liptobiolith from South China have been made, and the results of the study of various plant remains found ...Analysis, evaluation and statistics of dispersed cuticles, spores and wood pieces in Middle Devouian cutinitic liptobiolith from South China have been made, and the results of the study of various plant remains found in coals can be verified mutually. Meanwhile , the phyteral analysis of coals may contribute to our comprehensive knowledge or fossil floras and be used for the reconstruction of the peatforming plant commuuities.展开更多
Study on the fossil plants and the palynological assemblage is the basic botanical research on the coal bearing strata. The practice indicate that comprehensive data from the study on the fusinized wood fossil, the ph...Study on the fossil plants and the palynological assemblage is the basic botanical research on the coal bearing strata. The practice indicate that comprehensive data from the study on the fusinized wood fossil, the phyterals and the analysis of dispersed cuticles will effectively improve the level of the study on the coal bearing strata as a whole.展开更多
Numerous leaf compressions of Glyptostrobus europaeus (Brongn.) Ung. (Taxodiaceae) are found in Aquitanian (Lower Miocene) lignified clay localities Bolattam and Akzhar in the Southern Turgay, on the right bank of the...Numerous leaf compressions of Glyptostrobus europaeus (Brongn.) Ung. (Taxodiaceae) are found in Aquitanian (Lower Miocene) lignified clay localities Bolattam and Akzhar in the Southern Turgay, on the right bank of the Dulygaly-Zhilanshik river (Central Kazakhstan). The finely preserved lignified compression remains of leafy shoots make micro-morphological investigation feasible. Comparative studies of the epidermal features both living G. pensilis C. Koch and a new finding of G. europaeus from Early Miocene of Kazakhstan and illustrate their certain difference. The cuticular organization and epidermal features of fossil leaves, which have been compared with these of 'the nearest living relative', G. pensilis, were studied by scanning electron microscopy (SEM) and light microscopy (LM). The fossil leaves of G. europaeus from Kazakhstan are distinguished by stronger, than in living species, G. pensilis, developed 'micro-papillae' ('Kristallucken'), visible in SEM as ring-like structures left on the outer surface of cuticle in both nonstomatal and stomatal zones.展开更多
A new Quercus （Fagaceae） morphospecies is described based on well-preserved fossil leaves.The fossils were collected from Yangyi Formation of the Upper Pliocene at the Yangyi coalmine,Baoshan,western Yunnan,China.De...A new Quercus （Fagaceae） morphospecies is described based on well-preserved fossil leaves.The fossils were collected from Yangyi Formation of the Upper Pliocene at the Yangyi coalmine,Baoshan,western Yunnan,China.Details of the microstructure of mesophyll tissue are preserved because lithification of the fossils was not complete.The fossil laminas possess typical characteristics of Quercus sect.Heterobalanus：quite thick and coriaceous cuticle; secondary veins bifurcating near the margin in the middle and top of the leaf; and upper epidermis with adaxial hypodermis.Based on a detailed morphological and anatomical comparison with all living and fossil species of Quercus sect.Heterobalanus,the fossil leaves prove to be different in their sparse and garland-shaped multicellular trichomes on the lower epidermis,and so it is described as a new species Quercus yangyiensis He,Li et Sun sp.nov.The much sparser trichomes of our fossils compare well with those of living Quercus sect.Heterobalanus and indicate a more humid climate during the deposition of the Yangyi Formation in the Late Pliocene.展开更多
The cuticle of dung beetle is a layered composite material in micro- or nano-scale. Dung beetle can fly, walk and dig. It can shovel and compact dung of mammals into balls. It use foreleg to walk, midleg and hindleg ...The cuticle of dung beetle is a layered composite material in micro- or nano-scale. Dung beetle can fly, walk and dig. It can shovel and compact dung of mammals into balls. It use foreleg to walk, midleg and hindleg to hold and impel dung ball. Its two foreleges as digging legs are developed. The factors impacting the nanoindentation testing results of the femur cuticle of forelegs of dung beetle Copris ochus Motschulsky were examined. The nanomechanical test instrument used for the tests was Hysitron nanomechanical system. The results shown that the holding time and loading time are important factors im- pacting the accuracy of such indentation properties as reduced modulus (Er) and the harness ( H ) of the femur cuticle of the forelegs of dung beetle Copris ochus Motschulsky in nanoscale. There exists a threshold holding time of 20 s for the reduced modulus of the femur cuticle. The tests of nanoindentation creep property and the regression analysis of relationship between the depth increment at the maximum load and the time further confirmed the correction of the above threshold holding time. There exist visco-elastic-plastic behaviour and creep phenomenon in the femur cuticle during indenting. Its creep property during the holding procedure at maximum load can be regressed by a general logarithmic equation. The equation fitted by the testing data is ? h = 54.83452 ln(0.00723t +1.00486), where, ? h is the depth increment at the maximum load and t is the time.展开更多
Lindera is a large genus of graceful, pleasantly scented and common native trees and shrubs of southern China and neighboring regions of SE Asia. There is a well-documented Cenozoic fossil record not only in these reg...Lindera is a large genus of graceful, pleasantly scented and common native trees and shrubs of southern China and neighboring regions of SE Asia. There is a well-documented Cenozoic fossil record not only in these regions but also from elsewhere. A new fossil leaf record has been found in diatomite beds from the Upper Pliocene Mangbang Formation of Tuantian, Tengchong County, Yunnan. The leaves are identified and assigned to Lindera acuminatissima K. Q. Dao et B. N. Sun sp. nov., by comparing their leaf architecture and epidermal characteristics with those of 51 extant Lauraceae species and with 15 known fossil Lindera taxa. The specimens have well-preserved cuticles, with typical leaf architecture and epidermal characteristics of the Lanraceae, including entire leaf margin, intramarginal veins, basal ternate acrodromous primary veins, one-cell trichome base, paracytic stomatal apparatus, sunken guard cells, subsidiary hardly staining cells and presence of oil cells. These characteristics are consistent with Lindera sect. Daphnidium but are different from reported fossil and extant species of Lindera. The cuticles of Lindera are fragile and delicate with only three Lindera fossils reported based on this tissue. In terms of paleobiogeography, the fossil record indicates that Lindera is distributed in high- to mid-latitude regions of the Late Cretaceous to Paleocene northern hemisphere. Coincidentally, the records of Lindera located on both sides of the Bering Land Bridge possibly support the hypothesis that ancient plants extended via transcontinental exchanges through the Bering Corridor. In the Eocene, ancient Lindera spread to Europe through the Northern Degeer Route and the Southern Thulian Route. At the same time, ancient Lindera spread into Central Asia. Climatic changes and tectonization since the Neogene prevented the propagation of Lindera throughout Asia, North America and Europe, and hence the distribution areas have just regressed to the low-latitude regions in Asia and North America. From the Paleogene to the Neogene, Lindera has changed its distribution by surviving extreme climate changes. Quaternary glaciations ultimately led to Lindera becoming extinct in Europe. The new record from Tengchong, Yunnan, with its lower latitude located in tropical and subtropical regions, indicates that Lindera has lived in those regions since the late Pliocene.展开更多
Insect cuticular hydrocarbons(CHCs)serve as communication signals and protect against desiccation.They form complex blends of up to 150 different compounds.Due to differences in molecular packing,CHC classes differ in...Insect cuticular hydrocarbons(CHCs)serve as communication signals and protect against desiccation.They form complex blends of up to 150 different compounds.Due to differences in molecular packing,CHC classes differ in melting point.Communication is especially important in social insects like ants,which use CHCs to communicate within the colony and to recognize nestmates.Nestmate recognition models often assume a homogenous colony odor,where CHCs are collected,mixed,and redistributed in the postpharyngeal gland(PPG).Via diffusion,recognition cues should evenly spread over the body surface.Hence,CHC composition should be similar across body parts and in the PPG.To test this,we compared CHC composition among whole-body extracts,PPG,legs,thorax,and gaster,across 17 ant species from 3 genera.Quantitative CHC composition differed between body parts,with consistent patterns across species and CHC classes.Early-melting CHC classes were most abundant in the PPG.In contrast,whole body,gaster,thorax,and legs had increasing proportions of CHC classes with higher melting points.Intraindividual CHC variation was highest for rather solid,late-melting CHC classes,suggesting that CHCs differ in their diffusion rates across the body surface.Our results show that body parts strongly differ in CHC composition,either being rich in rather solid,late-melting,or rather liquid,early-melting CHCs.This implies that recognition cues are not homogenously present across the insect body.However,the unequal diffusion of different CHCs represents a biophysical mechanism that enables caste differences despite continuous CHC exchange among colony members.展开更多
The contribution of aliphatic-rich plant biopolymer to sorption of hydrophobic organic compounds is significantly important because of their preservation and accumulation in the soil environment, but sorption mechanis...The contribution of aliphatic-rich plant biopolymer to sorption of hydrophobic organic compounds is significantly important because of their preservation and accumulation in the soil environment, but sorption mechanism is still not fully understood. In this study, sorption of 1-naphthol by plant cuticular fractions was examined to better understand the contributions of respective fraction. Toward this end, cuticular materials were isolated from the fruits of tomato by chemical method. The tomato cuticle sheet consisted of waxes （6.5 wt%）, cuticular monomer （69.5 wt%）, and polysaccharide （24.0 wt%）. Isotherms of 1-naphthol to the cuticular fractions were nonlinear （N value （0.82 - 0.90）） at the whole tested concentration ranges. The K∞/Kow ratios for bulk cuticle （TC1）, dewaxed cuticle （TC2）, cutin （TC4）, and desugared cuticle （TC5） were larger than unity, suggested that tomato bulk cuticle and cutin are much powerful sorption medium. Sorption capability of cutin （TC4） was 2.4 times higher than the nonsaponifiable fraction （TC3）. The 1-naphthol interactions with tomato cuticular materials were governed by both hydrophobic-type interactions and polar （H-bonding） interactions. Removal of the wax and polysaccharide materials from the bulk tomato cuticle caused a significant increase in the sorption ability of the cuticular material. There was a linear negative trend between K∞ values and the amount of polysaccharides or fraction＇s polarities （（N＋O）/C）; while a linear positive relationship between K∞ values and the content ofcutin monomer （linear R^2 = 0.993） was observed for present in the cuticular fractions. Predominant sorbent of the hydrophobic organic compounds （HOCs） in the plant cuticular fraction was the cutin monomer, contributing to 91.7% of the total sorption of tomato bulk cuticle.展开更多
Ulomoides dermestoides （Chevrolat） （Coleop- tera： Tenebrionidae） is one of the most notorious pests in northeastern China. We examined microtrichia on the thorax, elytra and abdomen of U. dermestoides using scann...Ulomoides dermestoides （Chevrolat） （Coleop- tera： Tenebrionidae） is one of the most notorious pests in northeastern China. We examined microtrichia on the thorax, elytra and abdomen of U. dermestoides using scanning electron microscopy and recorded their confor- mations （size, shape and insertion method） and distribu- tions （length, width and location）. Possible functions of the microtrichia were （1） stridulation： microtrichia on the inner surface of the elytra interacted with microtrichia on the dorsoventral axis of the thorax or on the costal vein of the hind wing; （2） to increase friction： at the major surface on the middle of the abdominal tergum, hind-wings, inner surface of the medial edge of the elytra and the posterior end of the elytra; （3） protection： the microtrichia covering the posterior face of the abdomen conserved water in the body and protected the body from damage; and （4） sensing organ： the special shape of the microtrichia on the nerva- tion near the vannal fold of the hind wing, the anterio- metapleuron on the metathorax, and the posterior field of the abdomen could perceive the environment. In conclusion, the size and shape of the microtrichia are tightly related to their functions, which may have evolved with the beetles＇ lifestyle.展开更多
文摘Although the research on Cordaites of the Cathaysian Flora in China started early in 1883, the study of the cordaitean cuticles began late in 1991. Up to now, four types of cordaitean cuticles in situ and three types of dispersed ones have been reported from the Cathaysian Flora in China. However compared with the Euramerican Flora, the research work on cordaitean cuticles from the Cathaysian Flora in China is much more insufficient. In this paper, three kinds of dispersed cordaitean cuticles are described in detail from the Permian coal-bearing strata in China. Among these cuticles two kinds are collected from the roof shale of Coal Seam No. A(1) in Shanxi Formation (Lower Permian) in Xinzhuangzhi Coal Mine of Huainan, Anhui Province, southern border of North China Subprovince of the Cathaysian Flora in China. The third one was collected from Coal Seam No. 11 in the top of Longtan Formation (lower Upper Permian) in Dahebian Coal Mine of Shuicheng Mining District, Guizhou Province, South China Subprovince of the Cathaysian Flora in China. Comparison of these three kinds of cordaitean cuticles with the known ones from the Cathaysian Flora in China and from the Euramerican Flora is made. The authors consider that they are all new types of cordaitean cuticles. The significance they bear on palaeobotany is discussed.
基金project received financial support from the National Natural Science Foundation of China (No. 41262001)the Science and Technology Support Fund of Gansu Province (No. 1104FKCA116)
文摘Coniopteris was a ubiquitous plant of the Jurassic and Cretaceous periods and played an important role in the flora of the time. However, its anatomical structure is relatively poorly known. The specimens of Coniopteris hymenophylloides(Brongniart) Seward described here were collected from the Yaojie Formation in Gansu Province, northwestern China. The sterile fronds are characterized as being at least bipinnate with alternate arranged linear pinnae covered by thin cuticles. Fertile fronds are linear-lanceolate, with single sorus at the margin of each fertile pinnule. In situ spores are typically trilete, triangle to subcircular in polar view, cap-shaped in equatorial view, and 37 μm in average diameter. The trilete marking is straight and narrow, generally extends to 4/5 of the spore radius. The spore surface is smooth, and parts of the exine are granulated. The epidermal cells of cuticles are irregular in shape, approximately 40-60μm long and 10-20 μm wide. The elliptical stomatal complexes are paracytic,approximately 30 μm long and 19 μm wide,and irregularly distributed. On the basis of its epidermal structures and comparisons with extant ferns, we consider that Coniopteris displays combined features of the related extant genera.
基金supported by the National Natural Science Foundation of China (No. 20977081)the Foundation forthe Author of National Excellent Doctoral Dissertation of China (No. 200765)+1 种基金the Zhejiang Provincial Natural Science Foundation of China (No. R5100105)the Doctoral Fund of Ministry of Education of China (No.J20091588)
文摘To better understand the interaction mechanisms of plant surfaces with polar organic compounds, sorption of 4-chlorophenol, 2,4- dichlorophenol, and 2,4,6-trichlorophenol by fruit cuticles （i.e., tomato, apple, and pepper）, and potato tuber periderm were investigated. The roles of cuticular components （waxes, cutin, cutan and sugar） on sorption of chlorophenols are quantitatively compared. Cutin and waxes govern the sorption capacity of bulk apple cuticle by hydrophobic interactions. Potato periderm with highest sugar content exhibits the lowest sorption capability for the chlorophenols. With the increase of hydrophobicity （i.e., Kow ） of sorbate, the relative contribution of lipophilic components （wax, cutin and cutan） on total sorption increases, however, the ratios of Koc to Kow decreases due to increasing ionization degree of sorbates.
文摘We have developed a method where, after glutaraldehyde fixation, human hair shafts and insect cuticles are treated with ammonium thioglycolate (ATG) to improve ultrastructural staining. Conventional transmission electron microscopic (TEM) preparations do not distinguish the A-layer and the exocuticles of hair shafts. However, after ATG treatment, the A-layer appears in higher contrast. ATG treatment has also been used to observe the fibrillar structure in the cortex. In the cuticle of beetles, the epicuticle is stained by ATG. Although the human hair shaft (keratin) and insect cuticle (chitin) are composed of different materials, both can be reduced by the ATG solution. The ammonium in the ATG solution reacts with hair shafts and insect cuticles, causing a reduction of swelled cuticles. Therefore, ATG not only stains, but also reduces human hair shafts and the cuticles of beetles.
基金supported by the National Natural Science Foundation of China(32270340 and 31970824 to X.L.and 32300304 to H.Z.)the project“Fulltime introduction of high-end talent research project”(2020HBQZYC004 and A202105008 to X.L.)from Hebei provincefunding from the Hebei Natural Science Foundation(C2021205013 to X.L.,C2021205043 to L.G.,and C2023205049 to Y.Sun).
文摘After germination in the dark,plants produce a shoot apical hook and closed cotyledons to protect the quiescent shoot apical meristem(SAM),which is critical for seedling survival during skotomorphogenesis.The factors that coordinate these processes,particularly SAM repression,remain enigmatic.Plant cuticles,multilayered structures of lipid components on the outermost surface of the aerial epidermis of all land plants,provide protection against desiccation and external environmental stresses.Whether and how cuticles regulate plant development are still unclear.Here,we demonstrate that mutants of BODYGUARD1(BDG1)and long-chain acyl-CoA synthetase2(LACS2),key genes involved in cutin biosynthesis,produce a short hypocotyl with an opened apical hook and cotyledons in which the SAM is activated during skotomorphogenesis.Light signaling represses expression of BDG1 and LACS2,as well as cutin biosynthesis.Transcriptome analysis revealed that cuticles are critical for skotomorphogenesis,particularly for the development and function of chloroplasts.Genetic and molecular analyses showed that decreased HOOKLESS1 expression results in apical hook opening in the mutants.When hypoxia-induced expression of LITTLE ZIPPER2 at the SAM promotes organ initiation in the mutants,the de-repressed expression of cell-cycle genes and the cytokinin response induce the growth of true leaves.Our results reveal previously unrecognized developmental functions of the plant cuticle during skotomorphogenesis and demonstrate a mechanism by which light initiates photomorphogenesis through dynamic regulation of cuticle synthesis to induce coordinated and systemic changes in organ development and growth during the skotomorphogenesis-to-photomorphogenesis transition.
基金supported by CAS/SAFEA International Partnership Program for Creative Research Teams,the Pilot Project of Knowledge Innovation of CAS(Grant No.KZCX2-YW-105)National Basic Research Program of China(Grant No.2006CB806400)National Natural Science Foundation of China(Grant Nos.40402002,40872011)
文摘Leaf cuticle analysis has long been a powerful tool for fossil plant identification,systematics,and palaeoclimatological recon-struction.In recent decades the application of stomatal frequency data that are relied on precise calculation of stomata on plant fossil cuticles to reconstruct ancient atmospheric CO_(2)concentration made the preparation of cuticular membrane with sufficient size a critical technique in palaeoclimatological research.However,for plants with originally thin and fragile cuticles,e.g.,most deciduous plants,conventional techniques sometimes fail to obtain cuticular membranes with sufficient size,or sometimes unable to recover any.This has largely hampered the usage of fossil cuticle analysis in palaeobotanical and palaeo-climatological research.Here,we describe a new method using clear nail polish as a medium to"strengthen"the originally thin and fragile cuticles prior to maceration procedures.We demonstrate the method by using middle Eocene Metasequoia fossils that were notorious for the difficulty of recovering large-sized clean cuticular membranes due to their thin and fragile nature.Metasequoia,with well-documented and widely-distributed fossil records since the Late Cretaceous and with a living repre-sentative,114.glyptostroboides,as a comparative reference,bas been widely used as a model genus for the study of evolution of plants,palaeoclimatological reconstruction,and plant adaptation to climate changes.But its deciduous habit produces thin cuticles and makes the preparation of clean cuticular membranes a tedious process.The new method successfully allows us to recover its delicate cuticular membranes with sufficient sizes for SEM observation and stomatal frequency analysis.
基金supported by the National Natural Science Foundation of China(32161133010)the National Key Research and Development Program of China(2022YFD1700200)+2 种基金the Innovation Program of Chinese Academy of Agricultural Sciences(CAAS-CSCB-202302)the Shenzhen Science and Technology Program,China(KQTD20180411143628272)the Special Funds for Science Technology Innovation and Industrial Development of Shenzhen Dapeng New District,China(PT202101-02).
文摘Chitin is an abundant natural biopolymer that plays a crucial role in insect growth and development as a fundamental structural component of the exoskeleton.The membrane-integralβ-glycosyltransferase,chitin synthase,has been identified as the central component in chitin biosynthesis.However,the precise roles of other proteins in facilitating chitin synthase in chitin biosynthesis remain unclear.In this study,we employed split-ubiquitin membrane yeast two-hybrid(MYTH)and pull-down assays to demonstrate the physical interaction between Twinstar(Tsr),a small molecular protein in the actin-depolymerizing factor ADF/Cofilin protein family,and chitin synthase Krotzkopf verkehrt(Kkv)in Drosophila melanogaster in vitro.The RNA interference(RNAi)-mediated global knockdown of Tsr in D.melanogaster resulted in larval lethality.Furthermore,targeted suppression of Tsr in the tracheal and epidermal tissues also led to larval mortality,while knocking down Tsr in the wing tissues led to wrinkled wings.Additionally,silencing Tsr not only reduced the chitin content in the first longitudinal vein of the wings but also led to the absence of the chitin lamellar structure.To validate the functional conservation of Tsr in other insect orders,the two agricultural pests Ostrinia furnacalis and Tribolium castaneum,representing lepidoptera and coleoptera insects,respectively,were investigated.Knockdown experiments targeting the Drosophila Tsr orthologues OfTsr in O.furnacalis and TcTsr in T.castaneum produced abnormal larvae during molting or pupation in O.furnacalis and lethality in T.castaneum.Our findings not only improve ourknowledge of the chitin biosynthesis machinery in insect cuticles but also provide new potential targets for the control of major agricultural pests.
基金supported by the Key Research and Development Project of Henan Province,China(221111112200)the National Natural Science Foundation of China(32070502 and 32072419)+1 种基金the Fundamental Research Program of Shanxi Province,China(202303021224005)the Natural Science Foundation of Henan Province,China(232300420185).
文摘CRISPR/Cas9-based gene editing research has advanced greatly and shows broad potential for practical application in life sciences,but the Cas9 system is often constrained by the requirement of a protospacer adjacent motif(PAM)at the target site.While xCas9,a variant derived from Streptococcus pyogenes Cas9(SpCas9),can recognize a broader range of PAMs,its application in non-model insects is lacking.In this study,we explored xCas9 activity in gene editing by selecting corazonin(Crz)and the target sites with various PAMs in Locusta migratoria,a destructive insect pest worldwide.We found that xCas9 could cleave the target site with AG PAM while SpCas9 could not,although xCas9 appeared to have lower activity than SpCas9 at the canonical NGG PAMs.The heritable homozygous Crz^(-/-)locust strain was generated by the application of xCas9.The Crz^(-/-)strain showed an albino body color,with significantly downregulated expression of several body color-related genes including Pale,Vermilion,Cinnabar,White andβ-carotene-binding protein.In addition,Crz^(-/-)mutants exhibited significantly reduced expression of Chitin synthase 1,along with a markedly lower chitin content as well as compact and rigid cuticles.Furthermore,Crz^(-/-)mutants displayed impaired performance under low-temperature stress,including prolonged lifespan,reduced body weight and smaller body size.Our results suggest that xCas9 is effective for insect genome editing,and Crz plays essential roles in insect body color,cuticle development and adaptation to low-temperature stress.The findings of this study extend the application of xCas9 in non-model insects and provide new insights into our understanding of the regulation of insect cuticle development and environmental adaptation.
基金supported by the National Natural Science Foundation of China(Grant No.32402580)the Science and Technology Program of Guangdong Province(Grant No.2023A0505090005)Modern Seed Industry Innovation Capability Enhancement Project of Guangdong Academy of Agricultural Sciences.
文摘Extreme environmental conditions such as temperature fluctuations,drought,and pathogen attacks can significantly impact plant growth,development,and productivity.Plants have evolved intricate enzymatic systems to mitigate these stresses,among which GDSL esterase/lipase proteins (GELPs)-key members of the serine esterase/lipase superfamily-play important roles (Akoh et al.,2004).Characterized by a conserved GDSL motif and four essential amino acids (serine,glycine,asparagine,and histidine),GELPs exhibit versatile catalytic functions in lipid metabolism,cell wall modification,and stress responses (Ursache et al.,2021;Shen et al.,2022).
基金founded by the National Natural Science Foundation of China(Grant No.42073069)。
文摘Devonian cutinitic liptobiolith is a special type of coal formed during the early evolutionary stage of land plants.The Baishaping and Damaidi Devonian coals are notable for their distinct papery,sheet-like texture,and unusually high cutinite content(>50%),belonging to typical cutinitic liptobiolith.They are bituminous coals and have a suppressed vitrinite reflectance.Compared with typical typeⅢkerogen,these liptobioliths are characterized by extremely high yields of volatile matter and high hydrogen contents owing to their enhanced cutinite contents.As indicated by pyrolysis and elemental analysis results,the Devonian cutinitic liptobioliths are dominated by typeⅠ-Ⅱkerogens and have an excellent potential to generate liquid hydrocarbons.The Baishaping cutinitic liptobioliths are mainly composed of ribbon-like thick-walled cutinites,with small amounts of thin-walled type.Vitrinite is only present in trace amounts and is dominated by telinite.Meanwhile,the Damaidi Devonian coals are primarily composed of ribbon-like thin-walled cutinites,followed by collotelinites which are usually sandwiched by cutinites.The different petrological characteristics of the Baishaping and Damaidi liptobioliths might indicate a structural variation in the coal-forming plant cuticles and two distinct coal-forming conditions.The molecular bio markers in the Devonian coals are mainly composed of C_(18)-C_(20)tetracyclic diterpenoids,which are assumed to be the dominant soluble constituent of the Devonian land-plant cuticles and might have played an important role in early land plant radiation.Other molecules include aromatic tetracyclic diterpenoids,3-5 ring polycyclic aromatic hydrocarbons and their methylated counterparts,and C_(16)-and C_(18)-monocarboxylic acids.n-Alkanes are present only in small amounts.The molecular composition of the cutinite-rich coals is unexpected,because cuticular waxes are one of the most important sources of n-alkanes.In general,the petrology and geochemistry of the Devonian cutinitic liptobiolith indicate a distinct structure and composition for the early land-plant cuticles,which is significantly different from that of the plant cuticles since Carboniferous.Devonian cutinitic liptobioliths are of great interest because of their unique petrography,geochemistry,coal-forming plants,and oil-prone potential.Studies on this unique coal type provide a better understanding of coal-forming plants,paleoenvironment,paleoclimate,and early land-plant evolution in the Devonian.
基金carried out in the framework of the topic of the state task of the Institute of the Earth's Crust,Siberian Branch of the Russian Academy of Sciences(Project No.121042700218-2)this work involved the Centre of Geodynamics and Geochronology equipment at the Institute of the Earth's Crust(Grant No.075-15-2021682)。
文摘Two new species of Eretmophyllum Thomas are described from the lower(Toarcian)and upper(Aalenian)Prisayan Formation of the Irkutsk Basin,Eastern Siberia,Russia based on distinct morphological and cuticular features of the leaves that distinguish them from other species of the genus.Eretmophyllum polypapillosum sp.nov.is characterized by the presence of 2-3 papillae on the lower and upper epidermis of ordinary cells.Taphonomically,the leaf burials of E.polypapillosum sp.nov.indicate that it preferred mesophilic forests developed on river terraces and/or low watersheds.Eretmophyllum yershowskiensis sp.nov.is represented exclusively by leaf cuticles extracted by coal maceration,and it probably inhabited the low banks of peat bogs.The presence of the genus Eretmophyllum in the Early Jurassic of France and Eastern Siberia shows that it was already widespread in the territory of Eurasia,distributed from Western Europe to Eastern Siberia.This indicates the possible existence of Eretmophyllum species elsewhere in the Early Jurassic such as Central Asia and Northwest China.
文摘Analysis, evaluation and statistics of dispersed cuticles, spores and wood pieces in Middle Devouian cutinitic liptobiolith from South China have been made, and the results of the study of various plant remains found in coals can be verified mutually. Meanwhile , the phyteral analysis of coals may contribute to our comprehensive knowledge or fossil floras and be used for the reconstruction of the peatforming plant commuuities.
文摘Study on the fossil plants and the palynological assemblage is the basic botanical research on the coal bearing strata. The practice indicate that comprehensive data from the study on the fusinized wood fossil, the phyterals and the analysis of dispersed cuticles will effectively improve the level of the study on the coal bearing strata as a whole.
文摘Numerous leaf compressions of Glyptostrobus europaeus (Brongn.) Ung. (Taxodiaceae) are found in Aquitanian (Lower Miocene) lignified clay localities Bolattam and Akzhar in the Southern Turgay, on the right bank of the Dulygaly-Zhilanshik river (Central Kazakhstan). The finely preserved lignified compression remains of leafy shoots make micro-morphological investigation feasible. Comparative studies of the epidermal features both living G. pensilis C. Koch and a new finding of G. europaeus from Early Miocene of Kazakhstan and illustrate their certain difference. The cuticular organization and epidermal features of fossil leaves, which have been compared with these of 'the nearest living relative', G. pensilis, were studied by scanning electron microscopy (SEM) and light microscopy (LM). The fossil leaves of G. europaeus from Kazakhstan are distinguished by stronger, than in living species, G. pensilis, developed 'micro-papillae' ('Kristallucken'), visible in SEM as ring-like structures left on the outer surface of cuticle in both nonstomatal and stomatal zones.
基金financially supported by the National Basic Research Program of China(973 Program)(No.2012CB822003)the National Natural Science Foundation of China(No.41172022)Specialized Research Fund for the Doctoral Program of Higher Education(No.20120211110022)
文摘A new Quercus （Fagaceae） morphospecies is described based on well-preserved fossil leaves.The fossils were collected from Yangyi Formation of the Upper Pliocene at the Yangyi coalmine,Baoshan,western Yunnan,China.Details of the microstructure of mesophyll tissue are preserved because lithification of the fossils was not complete.The fossil laminas possess typical characteristics of Quercus sect.Heterobalanus：quite thick and coriaceous cuticle; secondary veins bifurcating near the margin in the middle and top of the leaf; and upper epidermis with adaxial hypodermis.Based on a detailed morphological and anatomical comparison with all living and fossil species of Quercus sect.Heterobalanus,the fossil leaves prove to be different in their sparse and garland-shaped multicellular trichomes on the lower epidermis,and so it is described as a new species Quercus yangyiensis He,Li et Sun sp.nov.The much sparser trichomes of our fossils compare well with those of living Quercus sect.Heterobalanus and indicate a more humid climate during the deposition of the Yangyi Formation in the Late Pliocene.
文摘The cuticle of dung beetle is a layered composite material in micro- or nano-scale. Dung beetle can fly, walk and dig. It can shovel and compact dung of mammals into balls. It use foreleg to walk, midleg and hindleg to hold and impel dung ball. Its two foreleges as digging legs are developed. The factors impacting the nanoindentation testing results of the femur cuticle of forelegs of dung beetle Copris ochus Motschulsky were examined. The nanomechanical test instrument used for the tests was Hysitron nanomechanical system. The results shown that the holding time and loading time are important factors im- pacting the accuracy of such indentation properties as reduced modulus (Er) and the harness ( H ) of the femur cuticle of the forelegs of dung beetle Copris ochus Motschulsky in nanoscale. There exists a threshold holding time of 20 s for the reduced modulus of the femur cuticle. The tests of nanoindentation creep property and the regression analysis of relationship between the depth increment at the maximum load and the time further confirmed the correction of the above threshold holding time. There exist visco-elastic-plastic behaviour and creep phenomenon in the femur cuticle during indenting. Its creep property during the holding procedure at maximum load can be regressed by a general logarithmic equation. The equation fitted by the testing data is ? h = 54.83452 ln(0.00723t +1.00486), where, ? h is the depth increment at the maximum load and t is the time.
基金conducted under the National Basic Research Program of China (973: No. 2012CB822000)the National Natural Science Foundation of China (Nos. 41172022 and 41172021)the Fundamental Research Funds for the Central Universities (No. lzujbky-2012-127)
文摘Lindera is a large genus of graceful, pleasantly scented and common native trees and shrubs of southern China and neighboring regions of SE Asia. There is a well-documented Cenozoic fossil record not only in these regions but also from elsewhere. A new fossil leaf record has been found in diatomite beds from the Upper Pliocene Mangbang Formation of Tuantian, Tengchong County, Yunnan. The leaves are identified and assigned to Lindera acuminatissima K. Q. Dao et B. N. Sun sp. nov., by comparing their leaf architecture and epidermal characteristics with those of 51 extant Lauraceae species and with 15 known fossil Lindera taxa. The specimens have well-preserved cuticles, with typical leaf architecture and epidermal characteristics of the Lanraceae, including entire leaf margin, intramarginal veins, basal ternate acrodromous primary veins, one-cell trichome base, paracytic stomatal apparatus, sunken guard cells, subsidiary hardly staining cells and presence of oil cells. These characteristics are consistent with Lindera sect. Daphnidium but are different from reported fossil and extant species of Lindera. The cuticles of Lindera are fragile and delicate with only three Lindera fossils reported based on this tissue. In terms of paleobiogeography, the fossil record indicates that Lindera is distributed in high- to mid-latitude regions of the Late Cretaceous to Paleocene northern hemisphere. Coincidentally, the records of Lindera located on both sides of the Bering Land Bridge possibly support the hypothesis that ancient plants extended via transcontinental exchanges through the Bering Corridor. In the Eocene, ancient Lindera spread to Europe through the Northern Degeer Route and the Southern Thulian Route. At the same time, ancient Lindera spread into Central Asia. Climatic changes and tectonization since the Neogene prevented the propagation of Lindera throughout Asia, North America and Europe, and hence the distribution areas have just regressed to the low-latitude regions in Asia and North America. From the Paleogene to the Neogene, Lindera has changed its distribution by surviving extreme climate changes. Quaternary glaciations ultimately led to Lindera becoming extinct in Europe. The new record from Tengchong, Yunnan, with its lower latitude located in tropical and subtropical regions, indicates that Lindera has lived in those regions since the late Pliocene.
基金This study was funded by a Heisenberg fellowship of the German Research Foundation to FM(Deutsche Forschungsgemeinschaft,grant no.ME 3842/6-1).
文摘Insect cuticular hydrocarbons(CHCs)serve as communication signals and protect against desiccation.They form complex blends of up to 150 different compounds.Due to differences in molecular packing,CHC classes differ in melting point.Communication is especially important in social insects like ants,which use CHCs to communicate within the colony and to recognize nestmates.Nestmate recognition models often assume a homogenous colony odor,where CHCs are collected,mixed,and redistributed in the postpharyngeal gland(PPG).Via diffusion,recognition cues should evenly spread over the body surface.Hence,CHC composition should be similar across body parts and in the PPG.To test this,we compared CHC composition among whole-body extracts,PPG,legs,thorax,and gaster,across 17 ant species from 3 genera.Quantitative CHC composition differed between body parts,with consistent patterns across species and CHC classes.Early-melting CHC classes were most abundant in the PPG.In contrast,whole body,gaster,thorax,and legs had increasing proportions of CHC classes with higher melting points.Intraindividual CHC variation was highest for rather solid,late-melting CHC classes,suggesting that CHCs differ in their diffusion rates across the body surface.Our results show that body parts strongly differ in CHC composition,either being rich in rather solid,late-melting,or rather liquid,early-melting CHCs.This implies that recognition cues are not homogenously present across the insect body.However,the unequal diffusion of different CHCs represents a biophysical mechanism that enables caste differences despite continuous CHC exchange among colony members.
基金Project supported by the National Natural Science Foundation of China (No.20577041,40671168)New Century ExceLlent Talents in University (No.NCET-05-0525).
文摘The contribution of aliphatic-rich plant biopolymer to sorption of hydrophobic organic compounds is significantly important because of their preservation and accumulation in the soil environment, but sorption mechanism is still not fully understood. In this study, sorption of 1-naphthol by plant cuticular fractions was examined to better understand the contributions of respective fraction. Toward this end, cuticular materials were isolated from the fruits of tomato by chemical method. The tomato cuticle sheet consisted of waxes （6.5 wt%）, cuticular monomer （69.5 wt%）, and polysaccharide （24.0 wt%）. Isotherms of 1-naphthol to the cuticular fractions were nonlinear （N value （0.82 - 0.90）） at the whole tested concentration ranges. The K∞/Kow ratios for bulk cuticle （TC1）, dewaxed cuticle （TC2）, cutin （TC4）, and desugared cuticle （TC5） were larger than unity, suggested that tomato bulk cuticle and cutin are much powerful sorption medium. Sorption capability of cutin （TC4） was 2.4 times higher than the nonsaponifiable fraction （TC3）. The 1-naphthol interactions with tomato cuticular materials were governed by both hydrophobic-type interactions and polar （H-bonding） interactions. Removal of the wax and polysaccharide materials from the bulk tomato cuticle caused a significant increase in the sorption ability of the cuticular material. There was a linear negative trend between K∞ values and the amount of polysaccharides or fraction＇s polarities （（N＋O）/C）; while a linear positive relationship between K∞ values and the content ofcutin monomer （linear R^2 = 0.993） was observed for present in the cuticular fractions. Predominant sorbent of the hydrophobic organic compounds （HOCs） in the plant cuticular fraction was the cutin monomer, contributing to 91.7% of the total sorption of tomato bulk cuticle.
基金supported by the National Natural Science Foundation of China(NSFC Grant No.31370649)
文摘Ulomoides dermestoides （Chevrolat） （Coleop- tera： Tenebrionidae） is one of the most notorious pests in northeastern China. We examined microtrichia on the thorax, elytra and abdomen of U. dermestoides using scanning electron microscopy and recorded their confor- mations （size, shape and insertion method） and distribu- tions （length, width and location）. Possible functions of the microtrichia were （1） stridulation： microtrichia on the inner surface of the elytra interacted with microtrichia on the dorsoventral axis of the thorax or on the costal vein of the hind wing; （2） to increase friction： at the major surface on the middle of the abdominal tergum, hind-wings, inner surface of the medial edge of the elytra and the posterior end of the elytra; （3） protection： the microtrichia covering the posterior face of the abdomen conserved water in the body and protected the body from damage; and （4） sensing organ： the special shape of the microtrichia on the nerva- tion near the vannal fold of the hind wing, the anterio- metapleuron on the metathorax, and the posterior field of the abdomen could perceive the environment. In conclusion, the size and shape of the microtrichia are tightly related to their functions, which may have evolved with the beetles＇ lifestyle.
