Immunolocalization of cell wall polymers in grapevine (Vitis vinifera) internodes under nitrogen, phosphorus or sulfur deficiency

Abstract The impact on cell wall (CW) of the deficiency in nitrogen (–N), phosphorus (–P) or sulphur (–S), known to impair essential metabolic pathways, was investigated in the economically important fruit species Vitis vinifera L. Using cuttings as an experimental model a reduction in total internode number and altered xylem shape was observed. Under –N an increased internode length was also seen. CW composition, visualised after staining with calcofluor white, Toluidine blue and ruthenium red, showed decreased cellulose in all stresses and increased pectin content in recently formed internodes under –N compared to the control. Using CW-epitope specific monoclonal antibodies (mAbs), lower amounts of extensins incorporated in the wall were also observed under –N and –P conditions. Conversely, increased pectins with a low degree of methyl-esterification and richer in long linear 1,5-arabinan rhamnogalacturonan-I (RG-I) side chains were observed under –N and –P in mature internodes which, in the former condition, were able to form dimeric association through calcium ions. –N was the only condition in which 1,5-arabinan branched RG- content was not altered, as –P and –S older internodes showed, respectively, lower and higher amounts of this polymer. Higher xyloglucan content in older internodes was also observed under –N. The results suggest that impairments of specific CW components led to changes in the deposition of other polymers to promote stiffening of the CW. The unchanged extensin amount observed under –S may contribute to attenuating the effects on the CW integrity caused by this stress. Our work showed that, in organized V. vinifera tissues, modifications in a given CW component can be compensated by synthesis of different polymers and/or alternative linking between polymers. The results also pinpoint different strategies at the CW level to overcome mineral stress depending on how essential they are to cell growth and plant development

Comparative in situ analyses of cell wall matrix polysaccharide dynamics in developing rice and wheat grain

Cell wall polysaccharides of wheat and rice endosperm are an important source of dietary fibre. Monoclonal antibodies specific to cell wall polysaccharides were used to determine polysaccharide dynamics during the development of both wheat and rice grain. Wheat and rice grain present near synchronous developmental processes and significantly different endosperm cell wall compositions, allowing the localisation of these polysaccharides to be related to developmental changes. Arabinoxylan (AX) and mixed-linkage glucan (MLG) have analogous cellular locations in both species, with deposition of AX and MLG coinciding with the start of grain filling. A glucuronoxylan (GUX) epitope was detected in rice, but not wheat endosperm cell walls. Callose has been reported to be associated with the formation of cell wall outgrowths during endosperm cellularisation and xyloglucan is here shown to be a component of these anticlinal extensions, occurring transiently in both species. Pectic homogalacturonan (HG) was abundant in cell walls of maternal tissues of wheat and rice grain, but only detected in endosperm cell walls of rice in an unesterified HG form. A rhamnogalacturonan-I (RG-I) backbone epitope was observed to be temporally regulated in both species, detected in endosperm cell walls from 12 DAA in rice and 20 DAA in wheat grain. Detection of the LM5 galactan epitope showed a clear distinction between wheat and rice, being detected at the earliest stages of development in rice endosperm cell walls, but not detected in wheat endosperm cell walls, only in maternal tissues. In contrast, the LM6 arabinan epitope was detected in both species around 8 DAA and was transient in wheat grain, but persisted in rice until maturity

Mango ( Mangifera Indica ) And Ambarella ( Spondias Cytherea ) Peel Extracted Pectins Improve Viscoelastic Properties Of Derived Jams

Food industries in developing countries are faced with the problem of inadequate supply of additives which can be met by proper utilization of local pectin sources. Mango ( Mangifera indica ) and ambarella ( Spondias cytherea ) peels are most of the time thrown into nature or used for animal feeding. They have been reported to be a potential source of pectins which could be used to process the fruits into various products. In order to assess their feasibility to be used in jam processing, ambarella and mango (Mango variety) peel pectins were extracted using three different extraction conditions: HCl at 85 °C/1h, water at 70 °C/1h and oxalic acid/ammonium oxalate (OAAO) at 85 °C/1h. Compare to commercial lime pectin with degree of methoxylation (DM) 70%, phase diagrams presenting sol-gel transition of purified pectins established as sucrose concentration (40-75 %, weight/weight) versus reduced pectin concentration (0.1-1.8 %, weight/weight) were studied at pH 3. Mango and ambarella jams were prepared with and without highly methoxylated peels pectins (0.4 %; DM 60-75%) and the effect of pectins on jam firmness was studied. Prepared hot jams, with 64 % of dry matter, 60 % of sucrose and/or 0.4 % of pectin, were characterized for their gelation kinetics and mechanical spectra at 20 °C. Phase diagrams showed that at pH 3, the minimal sucrose concentration used to obtain the gel is 40 % for OAAO mango pectin, 45 % for HCl mango and OAAO ambarella pectin, and 50 % for HCl ambarella and commercial pectin. Only gelation of OAAO extracted pectins was possible at low polymer (0.2 %) and standard sucrose (60 %) concentrations. Jams prepared without pectins exhibited a week gel behaviour (G' = 500-1000 Pa at 10 Hz) with those of ambarella being stronger than those of mango. Because of its good physicochemical characteristics, ambarella pulp was more suitable than mango pulp for jam processing. Mango and ambarella jams exhibited very strong gels (G'=2000-5000 Pa at 10 Hz) behaviour while using OAAO extracted pectins; the viscoelastic strength of the processing fruits increases 3-6 folds. Accordingly, OAAO extracted mango and ambarella peel pectins allow to obtain jams with excellent gelling properties

Lammi Kivitalot Oy:n teollisesti valmistettujen asuinrakennusten laadunvarmistusohje

Tämä opinnäytetyö on tehty Lammi-Kivitalot Oy:n tuotekehitysyksikölle. Tavoitteena oli luoda Lammi-Kivitalot Oy:lle laadunvarmistusohjeistus siten, että Lammi-Kivitalot Oy voi käyttää RT-kortin 80-10974 mukaisen laadunvarmistusohjeistuksen periaatteiden mukaisesti valmistamillansa asuinrakennuksilla ilmoitusmenettelyn mukaista vuotolukuarvoa. Tiukentuvat rakennusmääräykset ja energiatehokkuusvaatimukset ovat luoneet painetta rakennuksen ilmatiiveyden parantamiseksi. Rakennuksen ilmatiiveydellä on suuri merkitys rakennuksen asumisviihtyvyydelle, energiatehokkuudelle ja rakennuksen ulkovaipan rakennusfysikaaliselle toimivuudelle. Tutkimuksen lähtökohtana olivat Suomen ilmatiiveysmittaukseen liittyvät määräykset ja ohjeet. Aluksi perehdyttiin tiiviysmittauksia ohjaavaan standardiin SFS-EN 13829 sekä teollisesti valmistettujen asuinrakennusten laadunvarmistusohjeen ohjekorttiin RT 80-10974 sekä muihin aiheesta kirjoitettuihin teoksiin. Tutkimuksen teettäjä, Lammi Kivitalot Oy, halusi tutkituttaa koko tuotantoprosessinsa suunnittelusta valmiiseen asuinrakennukseen asti laadunvarmistusohjeistuksen mukaisesti. Tavoitteena oli tutkia ja kartoittaa prosessin heikot kohdat. Tavoitteena oli myös kehittää käytettyjä rakennedetaljeja ja kerätä työmailta arvokasta tietoa ja palautetta. Tämän tutkimuksen tuloksena parannettiin rakennedetaljit vastaamaan nykyisiä ilmatiiviysvaatimuksia. Asennuksen työohjeita parannettiin ja tämän tutkimuksen yhteydessä tehtiin yhtenäiset ilmatiiviysohjeet työmaille. Rakennustyömaan valvonnan helpottamiseksi koottiin vastaavalle työnjohtajalle valvonta-asiakirja, johon on kerätty ilmatiiveyteen liittyvät tärkeimmät työvaiheet. Rakennustietokortista 80-10974 löytyvän ilmoitusmenettelyn avulla saatiin Lammi Kivitalot Oy:n talotyypin suunnitteluarvoksi laskettua 1,0 m3/(h m2).The thesis was commissioned by Lammi Kivitalot Oy product development unit. The purpose of this study was to draw up quality control instructions for the company. The aim of the instructions is to enable the company to use the air leak value in residential buildings according to the principles set in RT 80-10974. The tightening building regulations and energy-efficiency requirements have put a pressure to improve the air tightness of the building. The air tightness of the building plays a significant role in the living comfort of the building, the energy-efficiency and in the building physical functionality of the envelope of the building. The regulations and instructions related to air tightness of buildings in Finland were studied. First, the standard SFS-EN 13829 directing air tightness measurements in Finland and the quality control instructions for residential buildings contained in RT 80-10974 were studied. The company’s whole manufacturing process all the way from the planning phase to the finished residential building was examined according to the quality control instructions to find the weak spots of the process. As a result of this thesis the structural details were improved to meet the present air tightness standards of residential buildings. The installation manuals were improved and the air tightness instructions were drawn up for the sites. A supervision document was compiled containing the most important stages related to the air tightness to help the supervision of the building site. The planning value for the house type manufactured by the company was calculated to be 1,0 m3/(h m2) based on the declaration method in RT 80-10974

LM6-M: A high avidity rat monoclonal antibody to pectic α-1,5-L-arabinan

1,5-arabinan is an abundant structural feature of side chains of pectic rhamnogalacturonan-I which is a matrix constituent of plant cell walls. The study of arabinan in cells and tissues is driven by putative roles for this polysaccharide in the generation of cell wall and organ mechanical properties. The biological function(s) of arabinan is still uncertain and high quality molecular tools are required to detect its occurrence and monitor its dynamics. Here we report a new rat monoclonal antibody, LM6-M, similar in specificity to the published rat monoclonal antibody LM6 (Willats et al. (1998) Carbohydrate Research 308: 149-152). LM6-M is of the IgM immunoglobulin class and has a higher avidity for α-1-5-L-arabinan than LM6. LM6-M displays high sensitivity in its detection of arabinan in in-vitro assays such as ELISA and epitope detection chromatography and in in-situ analyses

The deconstruction of pectic rhamnogalacturonan I unmasks the occurrence of a novel arabinogalactan oligosaccharide epitope

Rhamnogalacturonan I (RGI) is a pectic polysaccharide composed of a backbone of alternating rhamnose and galacturonic acid residues with side chains containing galactose and/or arabinose residues. The structure of these side chains and the degree of substitution of rhamnose residues are extremely variable and depend on species, organs, cell types and developmental stages. Deciphering RGI function requires extending the current set of monoclonal antibodies (mAbs) directed to this polymer. Here, we describe the generation of a new mAb that recognizes a heterogeneous subdomain of RGI. The mAb, INRA-AGI-1, was produced by immunization of mice with RGI oligosaccharides isolated from potato tubers. These oligomers consisted of highly branched RGI backbones substituted with short side chains. INRA-AGI-1 bound specifically to RGI isolated from galactan-rich cell walls and displayed no binding to other pectic domains. In order to identify its RGI-related epitope, potato RGI oligosaccharides were fractionated by anion-exchange chromatography. Antibody recognition was assessed for each chromatographic fraction. INRA-AGI-1 recognizes a linear chain of (1→4)-linked galactose and (1→5)-linked arabinose residues. By combining the use of INRA-AGI-1 with LM5, LM6 and INRA-RU1 mAbs and enzymatic pre-treatments, evidence is presented of spatial differences in RGI motif distribution within individual cell walls of potato tubers and carrot roots. These observations raise questions about the biosynthesis and assembly of pectin structural domains and their integration and remodeling in cell walls.fals