Premature Drying Research Articles

The study of oleander scale (Aspidiotus nerii Bche) and the way of diluting its entomophages in Azerbaijan

Scales (Hemiptera, Diaspididae) are the dangerous crop and park-ornamental plant pests. They reproduce very quickly and cause great harm to plants, sometimes even lead to their complete destruction. Scales suck juices from plants, cause premature drying, dying and falling off leaves, dry branches, deformation of leaves, fruits and shoots, reducing annual growth of plants. Therefore the fight with these pests is rather topical in the agriculture. In this connection in this work the analysis of bioecological peculiarities of oleander scale on the territory of Azerbaijan, and also the detection of species content of parasites and predators, which regulate their number is conducted. We will mark that oleander scales in the wild there are the entomophages are vermin and predators that reduce their quantity. For realization of biological fight against people we studied the bioenvironmental features of wreckers, and also educed specific composition of vermin and predators that regulate their quantity. In a biological fight against these wreckers, one of basic questions is study of specific composition of these entomophages. The faunistic material on entomophages of this pest was collected from different biocenosis; the researched works were conducted in the laboratory and field conditions in Azerbaijan. The advanced and research studies that we conducted gave an opportunity to educe entomophages oleander scale that inflicts an enormous damage to the agricultural cultures and park-decorative plants. The method of breeding of effective types of entomophages is studied in laboratory terms. Firstly the biology of oleander scale on Apsheron peninsula and in Guba Khachmazskii area was studied. The results of long-term studies showed that oleander scale, having distributed on Apsheron peninsula, on olive trees gives 3 generations. Only adult female animals and maggots of I and II age spend winter. Awakening of the scales on olives takes place in March-April. In II and III decade of April the male animals begin their flight. In Guba Khachmazskii area the biology of this scale, dwelling on oleander bush was studied. On this plant the scale gives 3 generations. Young female animals, and also maggots of I and II age winter. As a result of the works conducted the following entomophages of oleander scale were detected: predator Rhyzobius lophanthae Blaisd, Chilocorus bipustulatus L., Chilocorus renupustulatus L; parasites: Aphytis chilensis Howаrd, Aspidiotiphagus citrinus Graw, Encarsia aurantii (Howard). The habitat of Rhyzobius lophanthae is Australia. At the end of the last century of this predatory beetle left to California, from there left to Italy and in other Mediterranean countries. In 1947 by chance was left to Georgia (Abkhazia). Maybe these useful predators in Azerbaijan were from Georgia. For diluting the entomophages from the local indigenous fauna the potato tubers were used, on which firstly the oleander scales, and then road-beetles Rhyzobius lophanthae, Chilocorus bipustulatus reproduced themselves. In the laboratory conditions the methods of diluting of these Coccinellidae was developed. Thus, firstly the way of diluting parasites of oleander scale was studied and developed – Aphytis chilensis Howard, Aspidiotiphagus citrinus Graw и Encarsia antantii (Howard). It was detected that predatory entomophage-chilocor in the natural conditions is ineffective, as their maggots and chrysalises are affected by other local parasites. In the laboratory conditions this beetle produce itself very well on the potato tubers, infected by oleander scale. However, we should note that among entomophage parasites Aphytis chilensis plays the huge role in destruction of scales. In dependence on the weather conditions this macrophage in the nature can give 3–4 generations. Also it was proved that beetle Rhyzobius lophanthae in the biological fight can be applied against all round scales. This predator is effective entomophage of oleander, olive scale, black pine-leaf scale, white peach scale, European fruit scale and cactus scale. In connection with this, Rhyzobius lophanthae can be applied in the biological fight against oleander scale and presently is irreplaceable and perspective entomophage.

First Report of Corn Reddening Caused by 'Candidatus Phytoplasma solani' in Bulgaria.

Corn reddening (CR) or maize redness is a severe disease of corn (Zea mays L.) associated with 'Candidatus Phytoplasma solani' or stolbur phytoplasma (16SrXII-A). In Serbia, CR is continually present at a low frequency, while two outbreaks occurred in the late 1950s and 1990s. Its etiology was molecularly determined in 2006 (1). The first severe outbreak in Bulgaria was observed in Kneja in 1992, and in 2010 typical CR symptoms (leaf reddening, premature drying, and shriveled grains) were observed from Byala Slatina to Pleven. Although the number of CR affected plants was highly variable in different fields, the disease incidence in most cases was 30 to 50%, with an estimated yield reduction of about 20%. Leaf samples from four symptomatic corn plants were collected from Kneja, northwestern Bulgaria, in mid-August 2013. Extraction of DNA was performed from the main leaf midrib tissues using the CTAB method. Separate PCRs were carried out for amplification of the phytoplasma 16S rDNA and tuf genes using the phytoplasma specific primers P1/P7 and TufAyf/r, respectively. DNA from asymptomatic corn plants and reactions without template DNA were employed as negative controls, while DNA from periwinkle tissue infected with 'Ca. P. asteris' was used as a positive control. Amplicons of the expected sizes (1.7 and 0.9 kbp, respectively) were produced with DNA from three out of four symptomatic corn samples, while no amplification was observed with DNA from one symptomatic corn sample (probably because samples were collected during a drought period) nor the DNA from asymptomatic plants and negative control. RFLP analyses performed on 16S rDNA and tuf gene amplicons using Tru1I and HpaII restriction enzymes, respectively, revealed the presence of 'Ca. P. solani' (16SrXII-A, tuf type b) in all three positive samples (3). Both amplicons of a selected representative sample 241/13 were directly sequenced by a commercial service and the obtained sequences were deposited in NCBI GenBank under the accession number KF907506 for the16S rDNA (1,684 bp) and KF907507 for the tuf gene (896 bp). The 16S rDNA sequence of phytoplasma detected in Bulgarian corn shared a complete sequence identity with 'Ca. P. solani' strain from Serbian corn (JQ730750.1) and >99.7% sequence identity with the reference strain STOL (AF248959), while the tuf gene nucleotide sequence shared complete sequence identity with several 'Ca. P. solani' (e.g., Serbian strain 284/09, FO393427), thus confirming, with both genes, the affiliation of phytoplasmas in Bulgarian corn to 'Ca. P. solani'. This study adds new information on CR prevalence, previously reported in neighboring countries. Further studies will investigate the roles of Hyalesthes obsoletus and Reptalus panzeri, both polyphagous Cixiidae reported as CR vectors (2,4) in disease transmission in Bulgaria.

Characterization of a lily anther-specific gene encoding cytoskeleton-binding glycoproteins and overexpression of the gene causes severe inhibition of pollen tube growth.

This work characterizes an anther/pollen-specific gene that encodes potential intermediate filament (IF)-binding glycoproteins in lily (Lilium longiflorum Thunb. cv. Snow Queen) anthers during the development and pollen germination. LLP13 is a single gene that encodes a polypeptide of 807 amino acids, and a calculated molecular mass of 91 kDa. The protein contains a predicted transmembrane domain at the N-terminus and a conserved domain of unknown function (DUF)593 at the C-terminal half of the polypeptide. Sequence analysis revealed that LLP13 shares significant identity (37-41 %) with two intermediate filament antigen-binding proteins, representing a unique subgroup of DUF593 domain proteins from known rice and Arabidopsis species. The expression of LLP13 gene is anther-specific, and the transcript accumulates only at the stage of pollen maturation. Both premature drying and abscisic acid (ABA) treatment of developing pollen indicated that LLP13 was not induced by desiccation and ABA, but by other developmental cues. Antiserum was raised against the overexpressed LLP13C fragment of the protein in Escherichia coli and affinity-purified antibodies were prepared. Immunoblot analyses revealed that the LLP13 protein was a heterogeneous, anther-specific glycoprotein that accumulated only at the stage of pollen maturation. The protein is not heat-soluble. The level of LLP13 protein remained for 24 h during germination in vitro. Overexpression of LLP13-GFP or GFP-LLP13 in lily pollen tubes caused severe inhibition of tube elongation. The LLP13 protein codistributed with mTalin in growing tubes, suggesting that it apparently decorates actin cytoskeleton and is likely a cytoskeleton-binding protein that binds with IFs that potentially exist in pollen tubes.

Diseases of Rauvolfia Serpentina and their Biocontrol

Disease survey were conducted at Jabalpur, Bhopal, (Madhya Pradesh), Raipur, Bilaspur (Chhatisgarh.), revealed that R. serpentina suffered from leaf spot diseases caused by Mycosphaerella rauvolfiae, Cercospora rauvolfiae, Phoma jolyana, Cladosporium oxysporum, Macrophomina phaseolina, Alternaria alternata, A. tenuis, A. tenuissima. The inflorescence disease caused by Colletotrichun dematium cause heavy loss in seed production. Top dying caused by Lasiodiplodia theobromae and wilt disease caused by Fusarium oxysporum f. sp. ruavolfiae the fungus infects plants through the roots and invades the water conducting tissues of the plant and causing damage to the plant. Twig blight caused by Corynespora cassicola. Due to above diseases of leaves, inflorescence, roots and twigs led to premature drying, defoliation and death of the entire plant. For the management of above diseases laboratory and field experiments were performed. Laboratory experiments were conducted with biocontrolling agents (Bacillus firmus, B. amyloliquefaciens, Streptomyces sp.), cow urine and biopesticide (1 lit cow urine + 100 g fresh leaves each of Azadiracta indica, Ailanthus excelsa and Calotropis procera) to evaluate the best treatment for some of the major pathogens. On the basis of laboratory study foliar spraying in the field were conducted. The results showed that among all treatments Bavistin 0.05% + Streptomyces sp. (106 spores/ ml) showed less disease intensity as well as better seed yield, followed by Bavistin 0.05% + Trichoderma harzianum (106 spores/ml), Bavistin 0.05% and plant tonic (25 ml in 1000 ml). It is concluded that foliar application of Bavistin 0.05% + Streptomyces sp. (106 spores/ml), Bavistin 0.05% + T. harzianum (106 spores/ml), and Bavistin0.05% alone proved effective in protecting leaf spot and inflorescence diseases and increasing of seed production.

In Situ Synthesis and Nanoscale Evolution of Model Supported Metal Catalysts: Ni on Silica

The ability to disperse metal nanoparticles over a high surface area support is critical for catalyst preparation. For impregnation techniques, there are many fundamental questions about the spreading, diffusion, and coarsening behavior of metal intermediates during the drying and thermal treatments. We employ in situ environmental transmission electron microscopy to monitor the nanoscale processes taking place during the preparation of Ni on silica-supported metal model catalysts. Conventional salt impregnation techniques were employed, and the electron microscope was used to follow the spatial evolution of the material from salt impregnation through calcination and reduction. The best precursor dispersion was obtained with a nickel nitrate solution prepared in an ethanol solvent, followed by performing impregnation in an atmosphere saturated with ethanol vapor to avoid premature drying or deliquescence during mixing. In situ observations showed that no significant wetting or dispersion of the nickel pre...

Impact of the SpittlebugMahanarva spectabilison Signal Grass

The aim of this study was to determine the damage in Brachiaria ruziziensis (Germain & Edvard) according to the density of and exposure time to adults of Mahanarva spectabilis (Distant, 1909) (Hemiptera:Cercopidae). Each plant was kept with 0, 12, 18, or 24 adults of M. spectabilis for five or ten days. Then, the insects were removed from the plant, and the following parameters were evaluated: content and loss of chlorophyll, visual damage score, shoot dry mass, and the capability for regrowth. In fact, plants exposed to the highest level of infestation for 10 days showed an 80.97% loss of chlorophyll, which is 25% higher than that shown by the plants exposed for five days. The damage score also increased with infestation levels. In the levels of 12 and 18 adults per plant, the damage score increased with increasing time of exposure. The dry mass content was higher in plants exposed to 24 insects for 10 days, suggesting that the attack of spittlebugs caused premature drying of the plant. These effects caused significant reduction in the number of tillers of infested plants. Our results indicate that exposure to adults of M. spectabilis causes significant damage and affects the development and persistence of B. ruziziensis plants.

Research Regarding the Ecotechnological Factors that Influence the Biological Decline of the Vine, in the Wine Center Blaj

SUMMARY The biological decline of the vine is the result of multiple factors that may act simultaneously or successively, synergically or otherwise (Tomoiaga, 2006). The objective of this paper is to identify, monitor and characterize the ecotechnological risk factors that play a major role in the biological decline of the vine in the wine center Blaj. The study regarding the premature drying of the vine stocks was conducted during 2009-2010, on plots cultivated with the varieties Feteasca regala, Muscat Ottonel, Riesling Italian and Sauvignon blanc. During the study a number of 1000 stocks from each variety were analyzed. Observations were made both during growth time, as well as during the dormant stage of the vine. Among the ecotechnological risk factors, an important role is reserved to abiotic factors such as: temperature (sudden variations, late spring frosts, low temperatures during winter time), climatic accidents (heavy rainfalls, prolonged drought, hail), incorrect application of the cultivation technology (vine left unprotected during winter). The researchs undertaken in the field and laboratory have identified numerous pathogens responsible for the degradation of the bark and wood of the vine, the most important being: Agrobacterium tumefaciens, Eutypa lata, Phomopsis viticola, Stereum hirsutum (Tomoiaga, 2007). In 2010 the number of stocks affected by premature decline was significantly higher compared with 2009. The main contributing factors were both the unfavourable climatic conditions (the low temperatures in the winter of 2010, below the freezing limit of the vine; heavy rainfalls and the cool weather in the first part of the vegetation period) as well as the development of pathogens.

First report of Bipolaris australiensis causing pod rot of senna in India

Senna (Senna angustifolia) is used as a laxative and has replaced phenolphthalein as an active ingredient in various laxative medications (Verloop et al., 2004). It is cultivated on a large scale in the states of Rajasthan and Uttar Pradesh in north India, where incidence of Bipolaris pod rot disease on senna has been recorded for the first time. The disease was first observed in May 2010, and initially appeared in the form of brown, circular to irregular, minute to large necrotic spots on the pods which later turn into pod rot. Similar symptoms were also observed on leaves and stem. Seeds in infected pods were malformed and had reduced viability. Isolations carried out from the infected pods on potato dextrose agar (PDA) invariably yielded a species of Bipolaris. The fungus initially produced silky-smooth, greyish white colonies which later became olive green to black with a raised greyish periphery. Hyphae are septate and brown. Conidiophores are brown, simple or branched, geniculate and bear conidia sympodially (Fig. 1). Conidia range from 20-30μm x 7.5-10 μm (average 22.9 times 9.9 μm) and are three-septate, fusoid to cylindrical and light brown. Based on cultural and morphological characters, the fungus was identified as Bipolaris australiensis. The identification was later confirmed by IMTECH, Chandigarh, India and the culture deposited with Accession No. MTCC-10182. Pathogenicity of the fungus was tested on healthy attached senna pods under glasshouse conditions. B. australiensis was grown on PDA in petri dishes for 7-10 days and spores and mycelia scraped from the surface of the culture into sterile distilled water (SDW). An aqueous spore suspension containing 10 conidia/ml was sprayed over the wounded senna pods and plants were kept under high humidity (96%) for three days at 25 ± 2°C followed by a glasshouse at 25 ± 2°C and 75% humidity. In controls, pods were gently wounded and sprayed with SDW. Symptoms first appeared three to four days post inoculation and progressed from minute, brown necrotic spots to large dark brown patches on the infected pods (Fig. 2), then advanced towards leaves and stem causing premature drying of infected plants 20-25 days after inoculation. No symptoms were observed on control plants. Re-isolation from artificially infected pods consistently yielded B. australiensis thus fulfilling Koch's postulates. Senna has been reported to be affected by leaf blight caused by Alternaria alternata (Saxena et al., 1981)and leaf spot caused by Kabatiella sp.(Mitra et al., 1984)in India. B. australiensishas been previously reported on Cynodon (Fang et al., 2006), several turfgrasses (Smith et al., 1989) and betelvine (Piper betle) (Shahzad & Amer-Zareen, 1999) but a new record as a plant pathogen on senna (Fabaceae) is very significant. Thus, brown pod rot on senna caused by B. australiensis is the first report from India and worldwide. Authors are grateful to CSIR, New Delhi and Director, CIMAP, Lucknow for facilities. We also acknowledge IMTECH, Chandigarh for confirming identity of the pathogen.

Multigene sequence data and genetic diversity among ‘Candidatus Phytoplasma ulmi’ strains infecting Ulmus spp. in Serbia

Elm yellows phytoplasmas (EY) belonging to the 16SrV‐A subgroup were recently proposed as a new candidate species ‘Candidatus Phytoplasma ulmi’. These pathogens infect elm trees, causing leaf yellowing and premature drying. In this study, 25 isolates originating from localities in northeast, east and southwest Serbia were characterized by means of RFLP analysis and DNA sequencing of four genomic loci: 16S rRNA, ribosomal protein rpl22‐rps3, secY and map. In total, five different genotypes were identified based on collective sequencing of all four genes. Four of these genotypes showed significant nucleotide changes compared with the EY1T reference strain. Phylogeny based on parsimony analyses of ribosomal protein, secY and map genetic loci indicated a single monophyletic origin of EY1T and the new ‘Ca. Phytoplasma ulmi’ strains. Unlike phylogenetic clustering, DNA sequence comparison of EY1T and the novel strains revealed mutations in oligonucleotide signature sequences for all three genes (16S, rpl22‐rps3 and secY) used for the characterization and assignment of 16SrV‐A phytoplasmas to the ‘Ca. Phytoplasma ulmi’ species in the original description. Based on their high degree of genetic variability, the Serbian strains were assigned to four different subtypes of ‘Ca. Phytoplasma ulmi’ (EY‐S1, EY‐S2, EY‐S3 and EY‐S4). New diagnostic enzymes for practical use in ‘Ca. Phytoplasma ulmi’ identification are proposed for the 16S rRNA, ribosomal protein and secY genes. The implications of genetic variability within signature sequences for taxonomy and identification of ‘Ca. Phytoplasma’ species, as well as the importance of geographic variability and number of strains characterized for species description, are discussed.

Rop GTPase and Its Target Cdc42/Rac-Interactive-Binding Motif-Containing Protein Genes Respond to Desiccation during Pollen Maturation

Here, we report unique desiccation-associated ABA signaling transduction through which the Rop (Rho GTPase of plants) gene is regulated during the stage of pollen maturation. A gene encoding Rho GTPase was identified in lily (Lilium longiflorum Thunb.) pollen. Phylogenetic tree analysis of lily LLP-Rop1 revealed that the protein shares greatest similarity with Group 4 Rops. The LLP-Rop1 gene was spatially and temporally regulated in lily plants during anther development. Accumulation of the LLP-Rop1 transcript decreased its level of accumulation while LLP-12-2, a Rop-interactive CRIB motif-containing (RIC) transcript increased either by premature drying of developing anther/pollen or by the exogenous application of various concentrations of abscisic acid (ABA) during pollen maturation and tube growth. Application of norflurazon, an ABA biosynthesis inhibitor, also resulted in the downregulation of the LLP-Rop1 gene while LLP-12-2 was upregulated by ABA. Furthermore, an increase in ABA in the maturing pollen correlated with desiccation that occurred in the anther prior to anthesis. LLP-Rop1 overexpression inhibited tube elongation, and caused tube expansion and the formation of a ballooned tip. CFP-LLP-Rop1 was localized to the cytoplasm having a greater intensity along the tube plasma membrane. Fluorescence resonance energy transfer analysis of lily pollen tubes coexpressing CFP-LLP-Rop1 and YFP-LLP-12-2 demonstrated that LLP-12-2 is a target RIC protein of active LLP-Rop1, but the interaction between LLP-Rop1 and LLP-12-2 proteins is probably irrelevant of dehydration in the dried pollen.

Pond Characteristics and Occupancy by Red-Necked Phalaropes in the Mackenzie Delta, Northwest Territories, Canada

Red-necked phalaropes (Phalaropus lobatus) breed in Arctic and Subarctic lowlands throughout the circumpolar region. They are highly reliant on shallow freshwater ponds for social interaction, copulation, and foraging for small aquatic invertebrates. Threats related to warmer continental temperatures could lead to encroachment of shrub vegetation and premature drying of wetlands that serve as breeding habitat. We documented patterns of pond use over the breeding season and investigated pond characteristics associated with high occupancy by red-necked phalaropes. Research was conducted during two breeding seasons in a large wetland on Niglintgak Island, located in the mouth of the Mackenzie Delta, Northwest Territories. The frequency of pond occupancy declined between the onset of incubation and average hatch dates. Neither invertebrate assemblages (potential prey) nor physical characteristics (water chemistry and vegetation characteristics) varied significantly between ponds categorized as high-use, low-use, and no-use, in either year. Dry weight of potential prey (g/m3) was higher during the incubation period than during the nest initiation period. Pond occupancy both prior to and during incubation showed a clumped distribution, suggesting that choice of ponds was related in part to social stimulation. Future studies should examine the proximity of ponds to nest sites, the effects of premature drying of ponds on food availability, the distribution of resources surrounding ponds, and the occupancy of ponds by broods during the period preceding fall migration.

Using Well Water to Increase Hydroperiod as a Management Option for Pond-Breeding Amphibians

Drying of wetlands before the completion of larval development is a major factor controlling reproductive success of amphibians breeding in temporary ponds. For some endangered taxa, such drying can severely limit population viability and species survival. One way of reducing the impact of premature drying is to add water to temporary ponds via an outside source, but data on the value of this strategy are almost nonexistent. We tested whether water from nearby wells could be used to avoid pond drying and increase reproductive success for the endangered dusky gopher frog (Rana sevosa). During a 7-week period in 2001, we added over 366,000 L of water from nearby wells to the breeding site for this frog and were able to increase and maintain water levels until a heavy natural rainfall filled the pond basin. This avoided complete larval mortality and 130 metamorphic frogs were produced, the first successful reproduction since 1998. Our study provides an important initial step in evaluating the use of well water to increase the hydroperiod of breeding ponds for anurans; however, further studies should be undertaken before this method is used as a conservation tool to avoid larval mortality of imperiled amphibians.

Variation in Drying Behavior and Final Moisture Content of Wood during Conventional Low Temperature Drying and Vacuum Drying of Betula pendula Timber

Conventional and vacuum drying experiments were conducted on Betula pendula timber, which was sawn from trees felled during three different seasons. The influence of the wood procurement season on drying behavior differed, on the one hand, between the drying phases above and below 30% moisture content in the conventional drying, and, on the other hand, between the conventional and vacuum drying methods. During the first steps of the conventional drying process, relative humidity in the kiln, as well as drying time and drying rate, varied according to the felling season. Variations in environmental conditions outside the kiln and the seasonal variation in the physical properties of the wood were presumed to be the reasons for differences in drying behavior. The difference in moisture content gradient, i.e., the difference in final moisture content between the inner wood and the surface layer of boards, was greater in conventionally dried timber than in vacuum-dried timber. In conventionally dried timber there was a clear seasonal variation in the gradient of final moisture content, which was greatest for winter-felled wood. The premature drying of the surface layer during the first steps of the conventional drying process of winter-felled wood was the reason for the higher gradient of moisture content. Storage of wood as logs decreased the standard deviation of the final moisture content.

A lily pollen‐specific cDNA encoding the Cdc42/Rac‐interactive‐binding motif‐containing protein associated with pollen tube growth

This work characterizes a pollen‐specific and desiccation‐associated transcript that encodes the CRIB (Cdc42/Rac‐interactive‐binding) motif‐containing protein in lily (Lilium longiflorum Thunb. cv. Snow Queen) pollen during development and stress. The transcript, designated LLP12‐2, encodes a gene product having a sequence of 222 amino acids, a calculated molecular mass of 24 kDa, and a calculated pI of 9.1. The protein contains a high content of glycine, serine, and proline (11–16%) with relatively high amounts (8%) of arginine and lysine. Sequence analysis revealed that the LLP12‐2 is a Rho of plants‐ interactive CRIB motif‐containing protein (RIC), sharing 40–41% identities with RIC6, RIC7, and RIC8, all of which belong to Group II RICs in Arabidopsis. Antiserum was raised against the overexpressed LLP12‐2 protein in Escherichia coli. Affinity‐purified LLP12‐2 antibodies were prepared from antiserum to investigate the specificity and distribution of the protein during development. The affinity‐purified LLP12‐2 antibodies recognized both the 32‐ and 35‐kDa pollen proteins, and the two polypeptides were immunologically related. Immunoblot analyses of total protein from floral and vegetative organs confirmed that LLP12‐2 proteins accumulated to detectable levels only in a discrete stage of anther development. The level of LLP12‐2 protein remained for 24 h during germination in vitro, and they were eventually degraded thereafter. Premature drying of developing pollen indicated that the accumulation of LLP12‐2 proteins was associated with desiccation. Subcellular fractionation of pollen proteins revealed that the LLP12‐2 was located in the cytosolic fraction, correlated to the observation of the overexpressed GFP‐LLP12‐2 in pollen tubes. Nevertheless, it is preferably associated with tube plasma membrane, particularly at the apical region of pollen tubes. Overexpression of GFP‐LLP12‐2 in lily pollen tubes causes distinct tip‐growth phenotypes.

Biochemical characterization of a pollen-specific cDNA encoding polygalacturonase in Lilium longiflorum

A pollen-specific transcript, designated LLP-A1.1, in lily ( Lilium longiflorum Thunb. cv. Snow Queen) plants was isolated and characterized. The full-length cDNA encodes polygalacturonase (PG) having a sequence of 413 amino acids, a calculated molecular mass of 44 kDa, and a calculated p I of 8.1. Assessment of the hydropathy shows that the protein contains a hydrophobic segment at the N-terminus, indicating the presence of a putative signal peptide. The LLP-PG sequence displays significant resemblance to known pollen PG from various species and a group of major allergens including Phl p 13 of timothy grass and Pla a 2 of London planetree. Antiserum was raised against the overexpressed rLLP-PG protein in E. coli. Affinity-purified antibodies were prepared from antiserum to investigate the specificity and distribution of the protein during development. Immunoblot analyses of total protein from floral and vegetative organs confirmed that LLP-PG accumulated to detectable levels only in a discrete stage of anther development. It is a heterogeneous glycoprotein, consisting of four major and two minor polypeptides. Premature drying of developing anthers indicated that the lily LlpPG gene expression was not induced by desiccation that naturally occurs in pollen prior to anthesis.

Forced and natural carbonation of lime-based mortars with and without additives: Mineralogical and textural changes

We have studied the carbonation process in different types of mortars, with and without pozzolana or air-entraining additives, subject to a CO 2-rich atmosphere and compared the results with those of similar naturally carbonated mortars. We used X-ray diffraction technique to demonstrate that high CO 2 concentrations favour a faster, more complete carbonation process with 8 days being sufficient to convert portlandite into 90 wt.% calcite. Full carbonation, however, is not reached during the life-span of the tests, not even in forced carbonation experiments. This could be due to at least one of the following phenomena: a premature drying of samples during carbonation reaction, the temperature at which the carbonation process was carried out or the reduction of pore volume occupied by newly formed calcite crystals. This last option seems to be the least probable. We observed a more prolific development of calcite crystals in the pores and fissures through which the carbonic anhydride flows. Under natural conditions, carbonation is much slower and similar levels are not reached for 6 months. These differences suggest that the carbonation process is influenced by the amount of CO 2 used. Both the mineralogy and texture of mortars vary depending on the type of additive used but the speed of the portlandite–calcite transformation does not change significantly. Pozzolana produces hydraulic mortars although the quantity of calcium aluminosilicate crystals is low. The air-entraining agent significantly alters the texture of the mortars creating rounded pores and eliminating or reducing the drying cracks.

A desiccation-induced transcript in lily ( Lilium longiflorum) pollen

This work characterizes a desiccation and abscisic acid (ABA)-induced transcript, designated LLP-B3 , present in pollen of Lilium longiflorum during development and stress. The LLP-B3 cDNA encodes a gene product having a sequence of 160 amino acids, a calculated molecular mass of 17.8 kDa, and a pI of 4.3. The polypeptide is mainly hydrophilic having a stretch of hydrophobic region at the N-terminus, indicating the presence of a signal peptide. The expression of LLP-B3 gene is pollen-specific, and the transcript accumulates only at the stage of pollen maturation. Premature drying of developing pollen indicated that the accumulation of LLP-B3 transcripts was associated with desiccation. Treatment of pollen with abscisic acid resulted in the accumulation of LLP-B3 mRNA during germination. Sequence analysis demonstrates similarities between the predicted lily LLP-B3 protein and a corn Zmc13, a tomato LAT52, an arabidopsis leaf SAH7 and a group of major allergens including Ole e 1 of olive tree. Southern blots of lily genomic DNA indicate that LLP-B3 is a single or low copy number gene. The function of the desiccation-associated protein is discussed.

The competence to acquire cellular desiccation tolerance is independent of seed morphological development.

Acquisition of desiccation tolerance and the related changes at the cellular level in wheat (Triticum aestivum cv. Priokskaya) kernels during normal development and premature drying on the ear were studied using a spin probe technique and low temperature scanning electron microscopy. During normal development, the ability of embryos to germinate after rapid drying and rehydration was acquired after completion of morphological development, which is a few days before mass maturity. The acquisition of desiccation tolerance, as assessed by germination, was associated with an upsurge in cytoplasmic viscosity, the onset of accumulation of protein and oil bodies, and the retention of membrane integrity upon dehydration/rehydration. These features were also used to assess cellular desiccation tolerance in the cases when germination could not occur. Slow premature drying was used to decouple the acquisition of cellular desiccation tolerance from morphogenesis. Upon premature drying of kernels on the ears of plants cut at 5 d after anthesis, desiccation-tolerant dwarf embryos were formed that were able to germinate. When plants were cut at earlier stages poorly developed embryos were formed that were unable to germinate, but cellular desiccation tolerance was nevertheless acquired. In such prematurely dried kernels, peripheral meristematic endosperm cells had already passed through similar physiological and ultrastructural changes associated with the acquisition of cellular desiccation tolerance. It is concluded that despite the apparent strong integration in seed development, desiccation tolerance can be acquired by the meristematic cells in the developing embryo and cambial layer of endosperm, independently of morphological development.

New Fixation Technique for Preimplantation Genetics Diagnosis

Objectives: Current fixation techniques for preimplantation genetic diagnosis present an embryologist with several problems. These include premature drying, resulting in excess of cytoplasm; scattering which may lead to specimen loss; and significant variation in the required duration of treatment with pepsin. As a result, blastomeres or polar body fixation is a cumbersome and stressful process that requires extensive training. The development of an easier and more reproducible fixation technique is an important goal that was addressed in the present study.

A pollen-specific and desiccation-associated transcript in Lilium longiflorum during development and stress.

A cDNA clone encoding a desiccation-induced protein (LLA23) has been isolated from the mature pollen of a Lilium longiflorum cDNA library. Sequence analysis revealed significant similarity between the predicted LLA23 polypeptide, particularly at the C-terminal half of the sequence and a group of water-deficit/ripening-induced proteins. The expression of LLA23 gene is pollen-specific and the transcript accumulates only at the later stage of pollen maturation prior to anthesis. Premature drying of developing pollen confirmed that the accumulation of LLA23 transcripts was associated with desiccation. The LLA23 proteins decreased their levels when pollen/pollen tubes grew in the germination buffer. Treatments of pollen with abscisic acid (ABA) and polyethylene glycol (PEG)-8000 during germination greatly retarded the disappearance of LLA23 proteins and mRNAs. The LLA23 transcripts decreased their levels in pollen tubes grown both in vitro and in vivo, but the disappearance of LLA23 transcripts in tube cells grown in vivo was slower than those grown in vitro. In situ localization using anti-chicken immunoglobulin G conjugated with gold particles confirmed that LLA23 was located in the cytoplasm of pollen grains. The protective function of the desiccation-related proteins in the cytoplasm of pollen grains is proposed.