Molecular cloning and functional analysis of two calcium associated cuticular protein genes in Neocaridina denticulata sinensis

The body surface of crustaceans is covered with a sturdy shell.The growth and development of crustaceans are realized through molting.Neocaridina denticulata sinensis is a suitable candidate for crustacean scientific research.Two calcium-associated cuticular protein genes,named NdCAP-1 and NdCAP-2,were obtained from N.denticulata sinensis.Molecular docking simulated the binding effect of both proteins and calcium ions.Semi-quantitative reverse transcription PCR results show that NdCAP-1 is expressed in D_(2-4) stage,NdCAP-2 expressed in D_(2-4) and A-B stages,and both were significantly expressed in the cephalothorax cuticle and pereiopods.Then,it was revealed that NdCAP-1 and NdCAP-2 are regulated by NdEcR-mediated 20 E signaling pathways.Knockdown of NdCAP-1 and NdCAP-2 was observed to cause surface defects.The recombinant proteins(rNdCAP-1 and rNdCAP-2),obtained by prokaryotic expression,had calcium-binding and chitin-binding ability,inhibited formation of calcium carbonate precipitate.These results show that calcium-associated cuticular proteins play important roles in cuticle formation and calcification.

Differences in leaf cuticular wax induced by whole-genome duplication in autotetraploid sour jujube

Drought-resistant plants exhibit strong water retention capability.In this regard,the autotetraploid sour jujube leaves exhibit better water retention than diploid leaves.Morphological comparisons and physiological comparisons of diploid and autotetraploid leaves showed that the autotetraploid leaves had thicker leaf cuticles and more leaf wax accumulation than the diploid leaves,which could reduce cuticle permeability and improve the drought tolerance of leaves.In this study,the cuticular wax crystalloids on the adaxial and abaxial sides of young and mature jujube leaves were observed in the two ploidy types,and unique cuticular wax crystalloids covering a large area of the cuticle on autotetraploid sour jujube leaves may provide an advantage in reducing leaf non-stomata transpiration and improving plant drought tolerance.Based on the transcriptome,115 differentially expressed genes between diploids and autotetraploids were further analyzed and found to be involved in the accumulation of cuticular wax components,including terpenoids,fatty acids,and lipids,as well as ABC transporter and wax biosynthetic process.Finally,14 genes differentially expressed between glossy autotetraploid leaves and nonglossy diploid leaves,such as LOC107414787,LOC107411574 and LOC107413721,were screened as candidate genes by qRT-PCR analysis.This findings provided insights into how polyploidization improved drought tolerance.

ZmCER1,a putative ECERIFERUM 1 protein in maize,functions in cuticular wax biosynthesis and bulliform cell development

The cuticular wax,acting as the ultimate defense barrier,is essential for the normal morphogenesis of plant organs.Despite this importance,the connection between wax composition and leaf development has not been thoroughly explored.In this study,we characterized a new maize mutant,ragged leaf4(rgd4),which exhibits crinkled and ragged leaves starting from the sixth leaf stage.The phenotype of rgd4 is conferred by ZmCER1,which encoding an aldehyde decarbonylase involved in wax biosynthesis.ZmCER1 function deficient mutant displayed reduced cuticular wax density and disordered bulliform cells(BCs),while ZmCER1 overexpressing plants exhibited the opposite effects,indicating that ZmCER1 regulates cuticular wax biosynthesis and BCs development.Additionally,as the density of cuticular wax increased,the water loss rate of detached leaf decreases,suggesting that ZmCER1 is positively correlated with plant drought tolerance.

Comparative Analysis of Leaf Trichomes, Epidermal Wax And Defense Enzymes Activities in Response to Puccinia horiana in Chrysanthemum and Ajania Species

White rust caused by Puccinia horiana is a destructive disease of chrysanthemum plants.To better understand the resistance mechanisms of composite species to this disease,the leaf cuticular traits,antioxidant and defensive enzymes activities of immune(Chrysanthemum makinoi var.wakasaense)and highly susceptible(Ajania shiwogiku var.kinokuniense)species were compared.Trichome density of two species was markedly different,negatively associated with plant resistance to P.horiana.Total wax load in C.makinoi var.wakasaense was two times more than that in A.shiwogiku var.kinokuniense.The wax composition in immune one was abundant in esters and primary alcohols.Superoxide dismutase(SOD,EC 1.15.1.1),peroxidase(POD,EC 1.11.1.7),polyphenoloxidase(PPO,EC 1.14.18.1 or EC 1.10.3.2)and phenylalanine ammonia lyase(PAL,EC 4.3.1.5)activitieswere investigated.In C.makinoi var.wakasaense,the activity of SOD and POD increased rapidly after inoculation,whichmight be non-host induced reactive oxygen species(ROS)activated antioxidant enzymes,however SOD and POD remained a low and steady level in the highly susceptible one after inoculation.Quick increase in PPO activities after inoculation was observed in both species,however it remained higher in C.makinoi var.wakasaense at the late period of inoculation.PAL in C.makinoi var.wakasaense was induced after pathogen inoculation,but not in A.shiwogiku var.kinokuniense,suggesting that these two enzymes might contribute to the resistance to P.horiana.

QTL analysis reveals reduction of fruit water loss by NAC042 through regulation of cuticular wax synthesis in citrus fruit

Postharvest water loss is a critical factor that determines the quality and shelf life of fresh fruit.Cuticular wax constitutes a key barrier to reduce fruit water loss.Our previous study has shown that HJ(Citrus reticulata)has a significantly higher postharvest water loss rate than ZK(Poncirus trifoliata).Here,we investigated the fruit water loss rate of the HJ×ZK F1pseudo-testcross population in 2016 and 2019.QTL mapping for fruit water loss rate was performed by high-density genetic map and bulk segregant analysis,and QTL9 was identified to be associated with fruit water loss.The expression of NAC042 from QTL9 in ZK was 170-fold that in HJ.Heterologous expression in Arabidopsis showed that NAC042could reduce the water loss of leaves by increasing the cuticular wax content(especially alkanes).Further expression analysis revealed that NAC042 could enhance the expression of many wax-related genes in Arabidopsis leaves,including AtKCS1,AtKCS2,AtKCS9,AtKCS20,At CER1 and At CER3.Therefore,NAC042 might be involved in fruit cuticular wax synthesis to reduce fruit water loss.The findings provide new insights into the regulation of cuticular wax and fruit water loss as well as valuable information for breeding of citrus with better storability.

Solvent Effects on the Ultrastructure and Chemical Composition of Cuticular Wax and Its Potential Bioactive Role Against Alternaria alternata in Pingguoli Pear

Effects of different polarity solvents on the ultrastructure and chemical composition of cuticular wax in Pingguoli pear as well as their bioactive role against Alternaria alternate were studied and the results showed that the highest wax content was extracted with chloroform, and its wax content was up to 322.2 gg cm2. Long-chain fatty acids predominated in menthol extracts and n-alkanes were predominant in wax extracted with ether, chloroform and n-hexane. Pingguoli pear fruit surface was covered by a smooth and amorphous wax layer with small, scattered crystal. The morphology of recrystallized wax in vitro after removal with different solvents was not similar to that of the intact fruit surface. Removal of cuticular wax with various solvents significantly enhanced A. alternata infection, except for wax removed by methanol. The solvent extracts of methanol and chloroform stimulated the spore germination and mycelium growth ofA. alternata, but the ether and n-hexane extracts showed antifungal activity.

Preharvest application of 1-methylcyclopropene and Ethephon altered cuticular wax biosynthesis and fruit quality of apples at harvest and during cold storage

To investigate the roles of Harvista(a sprayable 1-methylcyclopropene,1-MCP,available component is 150 g·hm^(-2))and Ethephon(1 mL·L^(-1))applied at preharvest in apple(Malus domestica Borkh.'Golden Delicious')fruit cuticular wax biosynthesis,the expression of genes related to fruit cuticular wax biosynthesis and ethylene biosynthesis and signaling,ethylene production rate,respiration rate,wax constituents and structure,and fruit quality were determined at harvest and during cold storage.The results showed that 1-MCP inhibited the expression levels of ethylene biosynthesis and signaling-related genes,decreased fruit ethylene production,and inhibited the expression of Md LACS1,Md CER6,Md CER4 and Md WSD1,which resulted in decreases in alcohols,acids,and esters content in fruit cuticular wax.1-MCP also reduced fruit dropping rate from 17.17%to 12%;maintained fruit firmness,soluble solids,titratable acidity during cold storage;showed about as one fifth in the total length and one third in the widest width of wax crack as that in control at harvest.In contrast,Ethephon produced the opposite effects.In conclusion,1-MCP inhibited fruit ethylene biosynthesis and signaling,and influenced fruit cuticular wax biosynthesis.Thus,the fruit cuticular wax constituents and structure was altered,and the fruit quality were maintained at harvest and during cold storage.The results provide a new technology for improving apple fruit harvest and postharvest quality by preharvest application of sprayable 1-MCP.

Cuticular protein gene LmACP8 is involved in wing morphogenesis in the migratory locust,Locusta migratoria

Cuticular proteins(CPs)are major components of the insect cuticle-associated organs such as integument and wings,although the importance of CPs for wing development and function in hemimetabolous insects remains understudied.In the present study,a wing cuticular protein LmACP8 was identified from Locusta migratoria,which belongs to the RR-2 subfamily of cuticular protein R&R consensus(CPR)chitin-binding proteins.LmACP8 was mainly expressed in the wing pads and showed high expression levels before ecdysis of third-,fourth-,and fifth-instar nymphs,with its encoded protein located in the procuticle of wing pads and adult wings.Depletion of LmACP8 by RNA interference markedly reduced the amount of its protein,which consequently caused abnormal wing morphogenesis in the transition from nymph to adult of L.migratoria.We further demonstrated that the abnormal morphogenesis was caused by severe damage of the endocuticle in the wings.LmACP8 was suppressed by 20-hydroxyecdysone(20 E)in vivo,however,its expression was significantly up-regulated after knocking down the hormone receptor gene LmHR39.Thus,the LmACP8 that is negatively regulated by the LmHR39-mediated 20 E signaling pathway is involved in wing development during the nymph to adult transition.

Structures and Functions of Cuticular Wax in Postharvest Fruit and Its Regulation:A Comprehensive Review with Future Perspectives

Cuticular wax plays a major role in the growth and storage of plant fruits.The cuticular wax coating,which covers the outermost layer of a fruit’s epidermal cells,is insoluble in water.Cuticular wax is mainly composed of very long-chain fatty acids(VLCFAs);their derivatives,including esters,primary alcohols,secondary alcohols,aldehydes,and ketones;and triterpenoids.This complex mixture of lipids is probably biosynthesized in the epidermal cells of most plants and exuded onto the surface.Cuticular wax not only makes the fruit less susceptible to microbial infection but also reduces mechanical damage to the fruit,thereby maintaining the fruit’s commodity value.To date,research has mostly focused on the changes,function,and regulation of fruit wax before harvest,while ignoring the changes and functions of wax in fruit storage.This paper reviews on the composition,structure,and metabolic regulation of cuticular wax in fruits.It also focuses on postharvest factors affecting wax composition,such as storage temperature,relative humidity(RH),gas atmosphere,and as exogenous hormones;and the effects of wax on fruit postharvest quality,including water dispersion,fruit softening,physiological disorders,and disease resistance.These summaries may be of assistance in better understanding the changes in cuticular wax in postharvest fruit and the resulting effects on fruit quality.

Overexpression of ZxABCG11 from Zygophyllum xanthoxylum enhances tolerance to drought and heat in alfalfa by increasing cuticular wax deposition

Drought and heat stresses cause yield losses in alfalfa,a forage crop cultivated worldwide.Improving its drought and heat tolerance is desirable for maintaining alfalfa productivity in hot,arid regions.Cuticular wax forms a protective barrier on aerial surfaces of land plants against environmental stresses.ABCG11encodes an ATP binding cassette(ABC) transporter that functions in the cuticular wax transport pathway.In this study,Zx ABCG11 from the xerophyte Zygophyllum xanthoxylum was introduced into alfalfa by Agrobacterium tumefaciens-mediated transformation.Compared to the wild type(WT),transgenic alfalfa displayed faster growth,higher wax crystal density,and thicker cuticle on leaves under normal condition.Under either drought or heat treatment in greenhouse conditions,the plant height and shoot biomass of transgenic lines were significantly higher than those of the WT.Transgenic alfalfa showed excellent growth and 50% greater hay yield than WT under field conditions in a hot,arid region.Overexpression of Zx ABCG11 up-regulated wax-related genes and resulted in more cuticular wax deposition,which contributed to reduction of cuticle permeability and thus increased water retention and photosynthesis capacity of transgenic alfalfa.Thus,overexpression of Zx ABCG11 can simultaneously improve biomass yield,drought and heat tolerance in alfalfa by increasing cuticular wax deposition.Our study provides a promising avenue for developing novel forage cultivars suitable for planting in hot,arid,marginal lands.

Aβ-ketoacyl-CoA Synthase OsCUT1 Confers Increased Drought Tolerance in Rice

Drought stress is one of the major environmental factors affecting crop growth and productivity.Cuticular wax plays essential roles in protecting plants from environmental stress via forming a hydrophobic barrier on leaf epidermis.In this study,we analyzed nine members(OsCUT1‒OsCUT9)ofβ-ketoacyl-CoA synthase,the rate-limiting key enzyme for cuticular wax synthesis in rice by homology search and domain prediction.The expression levels of OsCUT genes under different abiotic stresses were investigated and OsCUT1 down-regulated by abiotic stress was selected for further function validation.Compared to the wild type,overexpression of OsCUT1(OX-OsCUT1)exhibited significantly increased drought resistance.Epicuticular wax was increased on the leaf surface of OX-OsCUT1 and the chlorophyll leaching experiment showed that the cuticular permeability was decreased in the OX-OsCUT1 plants.Moreover,overexpression of OsCUT1 didn’t result in the significant changes of major agronomic traits.In total,these results suggested that OsCUT1 is a promising gene for engineering rice plants with enhanced drought tolerance.

Overexpression of BnKCS1-1,BnKCS1-2,and BnCER1-2 promotes cuticular wax production and increases drought tolerance in Brassica napus

Higher amounts of cuticular wax in plants have been associated with improved plant stress tolerance and increased potential for industrial use.In this study,orthologs of KCS1 and CER1 in Arabidopsis,designated BnKCS1-1,BnKCS1-2,and BnCER1-2,were isolated from Brassica napus.Transcription of BnKCS1-1 and BnKCS1-2 in B.napus were induced by abscisic acid(ABA)and drought treatment,while transcription of BnCER1-2 was induced only by drought treatment.All three gene transcripts decreased significantly when plants were treated with methyl jasmonate(MeJA)or subjected to cold stress.Overexpression of BnKCS1-1,BnKCS1-2,and BnCER1-2 under the control of the CaMV35S promoter led to a significant increase in cuticular wax on transgenic B.napus leaves.BnKCS1-1 and BnKCS1-2 overexpression led to similar differences from non-transformed plants,with significantly higher levels of aldehydes(C29 and C30),alkanes(C28,C29,and C31)and secondary alcohols(C28 and C29),and a significantly lower level of C29 ketone.Overexpression of BnCER1-2 led to an increase in alkanes(C27,C28,C29,and C31),a decrease in secondary alcohols(C28 and C29),and insignificant changes in other wax components.Scanning electron microscopy revealed that overexpression of BnKCS1-1,BnKCS1-2,and BnCER1-2 in B.napus resulted in a higher density of wax crystals on the leaf surface than observed in non-transformed plants.Transgenic plants showed a reduced rate of water loss and increased drought tolerance compared to non-transformed plants.These results suggest that BnKCS1-1,BnKCS1-2,and BnCER1-2 gene products can modify the cuticular wax of B.napus.Changing cuticular waxes using transgenic approaches is a new strategy for genetic improvement of plant drought tolerance and provides an opportunity for development of B.napus as a surface-wax crop.

Study on the Repairing Effect of Cosmetics Containing <i>Artemisia annua</i>on Sensitive Skin

In view of the increasing sensitivity of consumer skin in recent years, cosmetics containing Artemisia annua extract was tested to evaluate its effectiveness in repairing sensitive skin. Through the experiment of xylene-induced ear swelling in mice, it was found that the inhibition rates of ear swelling in mice induced by xylene in three groups of cosmetics containing Artemisia annua extract reached 60.40%, 73.36% and 74.01%, respectively, close to the positive drug group. Twenty-five sensitive skin volunteers were selected for human clinical trial, and the skin TEWL value, cuticle hydration degree and skin heme (ultra-high concentration) were tested. The results showed that using cosmetics containing Artemisia annua extract for four weeks could effectively increase the hydration degree of cheek cuticle by 63.90% and reduce transepidermal waterloss (TEWL) by 21.51%. The skin heme (ultra-high concentration) decreased by 69.14% and the affected area decreased by 77.47%. The results show that the cosmetics containing Artemisia annua extract can inhibit inflammation, repair skin barrier, improve damaged skin, and reduce redness and other sensitive skin symptoms.

Immunological characterization of recombinant Wuchereria bancrofti cuticular collagen(COL-4)as putative vaccine candidate for human lymphatic filariasis

Objective:To elucidate immunoprophylactic potential of recombinant Wuchereria bancrofti(W.bancrofti)cuticular collagen(COL-4)in BALB/c mice and filarial clinical samples.Methods:col-4 gene was PCR amplified from W.bancrofti L3 cDNA library and cloned in pRSET B vector.Recombinant COL-4 was over expressed in salt inducible system and was purified by nickel afiinity chromatography.Humoral and cellular responses were measured by EUSA and peripheral blood mononuclear cells(PBMC)of various filarial clinical samples respectively using purified recombinant COL-4 antigen.Then the protective immune responses of COL-4 immunized BALB/c mice were characterized.Results:Sequence analysis of COL-4 with human host proteins reveals lack of homology.The recombinant COL-4 was found to be at 15 kDa fusion protein.The affinity purified COL-4 showed significant reactivity with putatively immune sere and in a similar fashion it demonstrated marked proliferation in PBMC samples.Immunization studies in experimental filarial host(mice)elicited significant liters with protective antibody isotype profile(IgM and IgG).Cellular immune responses were also significant in terms of splenocytes proliferation assay on mice samples.Conclusions:Our immunological findings in experimental host suggest Th2mediated immune response.Hence,we propose that W.bancrofti COL-4 could be an efficacious vaccine candidate against lymphatic filariasis.

Corn Leaf Water Retention as Affected by OrganicFertilizations and Effective Microbes Applications

Effects of organic fertilizers and effective microbes on leaf water retention of sweet corn (Zea mays L. cv.Honey-Bantam) were studied. Sweet corns were grown with organic or chemical fertilizers with or without effective microbes (EM). A water retention curve was obtained by drying the excised leaves under a light of 500 μmol (m2·s)-1. The curve shows two distinct phases. The initial steep slope indicates the water loss speed by stomatal transpiration (Est) and the gentle slope of the second phase indicates water loss speed by cuticular transpiration (Ecu). Both Est and Ecu were lower for leaves of plants grown with organic materials than for those with chemical fertilizers. Addition of EM to both organic and chemical fertilizers decreased Est but showed no effect on Ecu. The water retention ability of the excised leaves was proportional to photosynthetic maintenance ability under soil water deficit conditions as well as the solute concentration in leaves. The results suggested that organic fertilization and EM application increased water stress resistance both under in situ conditions and in excised leaves of sweet corn plants.

Fine mapping of a novel wax crystal-sparse leaf3 gene in rice

Cuticular wax plays an important role in protecting plants against water loss and pathogen infection and in the adaptations to environmental stresses. The genetic mechanism of the biosynthesis and accumulation of epicuticular wax in rice remains largely unknown. Here, we show a spontaneous mutant displaying wax crystal-sparse leaves and decreased content of epicuticular wax that was derived from the cytoplasmic male sterility （CMS） restorer line Zhenhui 714. Compared with the wild type Zhenhui 714, the mutant exhibited hydrophilic features on leaf surface and more sensitivity to drought stress. The mutation also caused lower grain number per panicle and thousand grain weight, leading to the decline of yield. Genetic analysis indicates that the mutation is controlled by a single recessive gene, named wax crystal-sparse leaf3 （wsl3）. Using segregation populations derived from crosses of mutant/Zhendao 88 and mutant/Wuyujing 3, respectively, the wsl3 gene was fine-mapped to a 110-kb region between markers c3-16 and c3-22 on chromosome 3. According to the rice reference genome and gene analysis, we conclude that a novel gene/mechanism involved in regulation of rice cuticular wax formation.

Leaf Traits and Histochemistry of Trichomes of Conocarpus lancifolius a Combretaceae in Semi-Arid Conditions

Leaf traits, structure and water status of Conocarpus lancifolius, a Combretaceae were investigated under semi-arid conditions. The leaf traits examined included leaf area and thickness, stomatal distribution, sclerophylly, succulence and relative water content. Additionally, the types of secretory structures, histochemistry of trichomes, and chemical nature of the cuticlular waxes were evaluated. Leaves showed xerophytic characteristics including a high degree of sclerophylly, thick cuticle and outer epidermal cell wall, low relative water content and high trichome density on younger leaves. The species has two types of trichomes;a secretory, short-stalked capitate trichome and a non-secretory trichome with a bulbous base and a pointed tip. The leaves also have a pair of extrafloral nectaries on both sides of the distal end of the petiole, 3-4 pairs near the leaf apex and two secretory ducts or cavities on mature leaves that secreted polysaccharides, epicuticlar waxes and polyphenols. Compared to young leaves mature leaves had almost 3 times total cuticular wax deposit or load. The most abundant fatty acids were palmitic, stearic, nondecanoic, behenic and arachidic acids. The leaf traits and structures are discussed in relation to semi-arid habitat.

Trade-offs between the accumulation of cuticular wax and jasmonic acid-mediated herbivory resistance in maize

Plants have evolved complex physical and chemical defense systems that allow them to withstand herbivory infestation.Composed of a complex mixture of very-long-chain fatty acids(VLCFAs)and their derivatives,cuticular wax constitutes the first physical line of defense against herbivores.Here,we report the function of Glossy 8(ZmGL8),which encodes a 3-ketoacyl reductase belonging to the fatty acid elongase complex,in orchestrating wax production and jasmonic acid(JA)-mediated defenses against herbivores in maize(Zea mays).The mutation of GL8 enhanced chemical defenses by activating the JA-dependent pathway.We observed a trade-off between wax accumulation and JA levels across maize glossy mutants and 24 globally collected maize inbred lines.In addition,we demonstrated that mutants defective in cuticular wax biosynthesis in Arabidopsis thaliana and maize exhibit enhanced chemical defenses.Comprehensive transcriptomic and lipidomic analyses indicated that the gl8 mutant confers chemical resistance to herbivores by remodeling VLCFA-related lipid metabolism and subsequent JA biosynthesis and signaling.These results suggest that VLCFA-related lipid metabolism has a critical role in regulating the trade-offs between cuticular wax and JA-mediated chemical defenses.

A reference-grade genome of the xerophyte Ammopiptanthus mongolicus sheds light on its evolution history in legumes and droughttolerance mechanisms

Plants that grow in extreme environments represent unique sources of stress-resistance genes and mechanisms.Ammopiptanthus mongolicus(Leguminosae)is a xerophytic evergreen broadleaf shrub native to semi-arid and desert regions;however,its drought-tolerance mechanisms remain poorly understood.Here,we report the assembly of a reference-grade genome for A.mongolicus,describe its evolutionary history within the legume family,and examine its drought-tolerance mechanisms.The assembled genome is 843.07 Mb in length,with 98.7%of the sequences successfully anchored to the nine chromosomes of A.mongolicus.The genome is predicted to contain 47611 protein-coding genes,and 70.71%of the genome is composed of repetitive sequences;these are dominated by transposable elements,particularly longterminal-repeat retrotransposons.Evolutionary analyses revealed two whole-genome duplication(WGD)events at 130 and 58 million years ago(mya)that are shared by the genus Ammopiptanthus and other legumes,but no species-specific WGDs were found within this genus.Ancestral genome reconstruction revealed that the A.mongolicus genome has undergone fewer rearrangements than other genomes in the legume family,confirming its status as a"relict plant".Transcriptomic analyses demonstrated that genes involved in cuticular wax biosynthesis and transport are highly expressed,both under normal conditions and in response to polyethylene glycol-induced dehydration.Significant induction of genes related to ethylene biosynthesis and signaling was also observed in leaves under dehydration stress,suggesting that enhanced ethylene response and formation of thick waxy cuticles are two major mechanisms of drought tolerance in A.mongolicus.Ectopic expression of AmERF2,an ethylene response factor unique to A.mongolicus,can markedly increase the drought tolerance of transgenic Arabidopsis thaliana plants,demonstrating the potential for application of A.mongolicus genes in crop improvement.

Rice OsGL 1-1 Is Involved in Leaf Cuticular Wax and Cuticle Membrane

Cuticular wax forms a hydrophobic barrier on aerial plant organs; it plays an important role in protecting a plant from damage caused by many forms of environmental stress. In the present study, we characterized a rice leaf wax-deficient mutant osgll-1 derived from a spontaneous mutation, which exhibited a wax-deficient and highly hydro- philic leaf phenotype. We cloned the OsGLI-1 gene by the map-based cloning method and performed a complementation test to confirm the function of the candidate gene. Molecular studies revealed that OsGLI-1 was a member of the OsGL1 family, and contained regions that were homologous to some regions in sterol desaturases and short-chain dehydro- genases/reductases. Compared to the wild-type, the osgll-1 mutant showed decreased cuticular wax deposition, thinner cuticular membrane, decreased chlorophyll leaching, increased rate of water loss, and enhanced sensitivity to drought. OsGL 1-1 is expressed ubiquitously in rice. The transient expression of OsGLl-l-green fluorescent protein fusion protein indicated that OsGLI-1 is localized in the cytoplasm, plasma membrane, and nucleus.