Expression of small heat shock proteins and heat tolerance in potato (Solanum tuberosum L.)

We have examined the correlation between heat tolerance and small heat shock protein (sHSP) expression under heat stress conditions in potato (Solanum tuberosum L.). The relative heat tolerance of nine potato cultivars grown under greenhouse conditions was determined using the electrolyte leakage assay (ELA), a standard quantitative assay for heat tolerance. Three cultivars differing in heat tolerance were selected and designated as heat-tolerant (‘Laura’), moderately sensitive (‘Liseta’) and heat-sensitive (‘Agria’) genotypes. The expression of cytosolic HSP18 and chloroplast HSP21 was analyzed at the protein level in the leaves of selected cultivars, both ex vitro- and in vitro-grown, after heat stress or control treatment. Immunoblot analysis revealed heat-induced HSP18 and HSP21 expression in all examined genotypes. A similar pattern of examined sHSP expression was observed ex vitro and in vitro: heat-tolerant ‘Laura’ accumulated higher levels of both HSP18 and HSP21 compared to heat-sensitive ‘Liseta’ and ‘Agria’. Our results indicate that ELA combined with immunoblot analysis of sHSP accumulation under HS conditions, might be considered as a reliable procedure in screening potato genotypes for heat tolerance. To our knowledge, this is the first study where sHSP expression between ex vitro- and in vitro-grown potato plants was compared

Expression of small heat shock proteins and heat tolerance in potato (Solanum tuberosum L.)

We have examined the correlation between heat tolerance and small heat shock protein (sHSP) expression under heat stress conditions in potato (Solanum tuberosum L.). The relative heat tolerance of nine potato cultivars grown under greenhouse conditions was determined using the electrolyte leakage assay (ELA), a standard quantitative assay for heat tolerance. Three cultivars differing in heat tolerance were selected and designated as heat-tolerant (‘Laura’), moderately sensitive (‘Liseta’) and heat-sensitive (‘Agria’) genotypes. The expression of cytosolic HSP18 and chloroplast HSP21 was analyzed at the protein level in the leaves of selected cultivars, both ex vitro- and in vitro-grown, after heat stress or control treatment. Immunoblot analysis revealed heat-induced HSP18 and HSP21 expression in all examined genotypes. A similar pattern of examined sHSP expression was observed ex vitro and in vitro: heat-tolerant ‘Laura’ accumulated higher levels of both HSP18 and HSP21 compared to heat-sensitive ‘Liseta’ and ‘Agria’. Our results indicate that ELA combined with immunoblot analysis of sHSP accumulation under HS conditions, might be considered as a reliable procedure in screening potato genotypes for heat tolerance. To our knowledge, this is the first study where sHSP expression between ex vitro- and in vitro-grown potato plants was compared.Projekat ministarstva br. TR3104

High biomass producing root cultures of Gentiana punctata L. transformed with Agrobacterium tumefaciens C58Cl(pArA4b)

Gentiana punctata L. shoot cultures were transformed with Agrobacterium tumefaciens clone C58C1 harbouring A. rhizogenes A4 Ri plasmid (pRiA4b) to produce hairy roots capable of autonomous growth on growth regulator-free medium. Optimal medium comprised WPM macro-nutrient salts, MS micro-salts and iron, LS vitamins and 2% sucrose. Successful transformation was confirmed by PCR amplification of awe 1 and rol C sequences. Excised, transgenic root cultures characterized by intensive lateral root branching enabled high biomass production. Fast growth required use of explants with small initial weight and frequent subculturing. Cultures were maintained for 10 years (more than 100 subcultures) without changes in morphology or physiological responses.Kulture izdanaka Gentiana punctata L. transformisane su transkonjugovanim sojem Agrobacterium tume-faclens klon C58C1 sa ubačenim A. rhizogenes A4 Ri plazmidom (pArA4b) koji produkuje korenove sposobne za autonoman rast na podlozi bez regulatora rastenja. Uspešna transformacija pokazana je PCR amplikacijom aih 1 i rol C sekvenci u uzorcima transformisanih korenova. Kulture transgenih korenova koje su se karakterisale intenzivnim bočnim grananjem, održavane su tokom 10 godina (90 i više subkultura) bez promena u morfologiji i fiziološkim svojstvima. Optimalni uslovi za rast ovih kultura bili su tečna podloga i 2% saharoza. Brz porast kultura zahtevao je male početne eksplantate i česta pasažiranja na svežu podlogu.nul

Effects of operation temperature on thermal expansion and main parameters of radial ball bearings

The research of influence of operation temperature on the thermal expansion and main parameters of radial ball bearings is presented in this paper. The main bearing parameters are identified in accordance with the increasing requests concerning stability and load capacity. A series of finite element analyses is performed for quasi-static analysis of all identified bearing parameters during contact period in referent temperature. Then, the dependence of bearing material characteristics on the operation temperature is discussed. Few series of finite element analyses are performed for a particular radial ball bearing type, with characteristics in accordance with manufacturer specifications, for several operation temperatures. These two problems analyses include consideration of relation between the initial radial clearance, thermal expansion strains, and contact deformations of the parts of the bearing assembly. The results for radial ball bearing parameters are monitored during a ball contact period for different temperatures and the appropriate discussion and conclusions are given. The conclusions about the contribution of developed procedure in defining the optimum operation temperature range are shown

Effects of operation temperature on thermal expansion and main parameters of radial ball bearings

The research of influence of operation temperature on the thermal expansion and main parameters of radial ball bearings is presented in this paper. The main bearing parameters are identified in accordance with the increasing requests concerning stability and load capacity. A series of finite element analyses is performed for quasi-static analysis of all identified bearing parameters during contact period in referent temperature. Then, the dependence of bearing material characteristics on the operation temperature is discussed. Few series of finite element analyses are performed for a particular radial ball bearing type, with characteristics in accordance with manufacturer specifications, for several operation temperatures. These two problems analyses include consideration of relation between the initial radial clearance, thermal expansion strains, and contact deformations of the parts of the bearing assembly. The results for radial ball bearing parameters are monitored during a ball contact period for different temperatures and the appropriate discussion and conclusions are given. The conclusions about the contribution of developed procedure in defining the optimum operation temperature range are shown

Dehydration-related changes of peroxidase and polyphenol oxidase activity in fronds of the resurrection fern Asplenium ceterach L.

Asplenium ceterach belongs to a group of poikilohydric ferns and it can recover uninjured from an almost completely dehydrated state. In our study, short term dehydration (24h) at four different water potentials, resulted in moderate water loss (partial desiccation) in fern tissue. The main phenolic acids represented in A. ceterach were chlorogenic (CGA) and caffeic acid (CA) and their content decreased during the dehydration process. For the first time, peroxidase (POD) and polyphenol oxidase (PPO) isoforms were determined in the rustyback fern. The results exhibit the presence of numerous anionic POD isoforms, with pI ranging from 4.4 to 5.8, but none of the cationic isoforms was detected. Two PPO isoforms were identified, one anionic with pI 6.3 and one cationic with pI of about 9.0. Short-term dehydration brought about a remarkable increase in POD and PPO activity using CGA as a substrate. Changes in enzyme activity and content of substrates during dehydration may play an important role in the adaptation of the rustyback fern to water deficit, and increase the overall plant resistance to stress conditions.nul

Expression of small heat shock proteins and heat tolerance in potato (Solanum tuberosum L.)

We have examined the correlation between heat tolerance and small heat shock protein (sHSP) expression under heat stress conditions in potato (Solanum tuberosum L.). The relative heat tolerance of nine potato cultivars grown under greenhouse conditions was determined using the electrolyte leakage assay (ELA), a standard quantitative assay for heat tolerance. Three cultivars differing in heat tolerance were selected and designated as heat-tolerant (‘Laura’), moderately sensitive (‘Liseta’) and heat-sensitive (‘Agria’) genotypes. The expression of cytosolic HSP18 and chloroplast HSP21 was analyzed at the protein level in the leaves of selected cultivars, both ex vitro- and in vitro-grown, after heat stress or control treatment. Immunoblot analysis revealed heat-induced HSP18 and HSP21 expression in all examined genotypes. A similar pattern of examined sHSP expression was observed ex vitro and in vitro: heat-tolerant ‘Laura’ accumulated higher levels of both HSP18 and HSP21 compared to heat-sensitive ‘Liseta’ and ‘Agria’. Our results indicate that ELA combined with immunoblot analysis of sHSP accumulation under HS conditions, might be considered as a reliable procedure in screening potato genotypes for heat tolerance. To our knowledge, this is the first study where sHSP expression between ex vitro- and in vitro-grown potato plants was compared.Projekat ministarstva br. TR3104

High biomass producing root cultures of Gentiana punctata L. transformed with Agrobacterium tumefaciens C58Cl(pArA4b)

Gentiana punctata L. shoot cultures were transformed with Agrobacterium tumefaciens clone C58C1 harbouring A. rhizogenes A4 Ri plasmid (pRiA4b) to produce hairy roots capable of autonomous growth on growth regulator-free medium. Optimal medium comprised WPM macro-nutrient salts, MS micro-salts and iron, LS vitamins and 2% sucrose. Successful transformation was confirmed by PCR amplification of awe 1 and rol C sequences. Excised, transgenic root cultures characterized by intensive lateral root branching enabled high biomass production. Fast growth required use of explants with small initial weight and frequent subculturing. Cultures were maintained for 10 years (more than 100 subcultures) without changes in morphology or physiological responses.Kulture izdanaka Gentiana punctata L. transformisane su transkonjugovanim sojem Agrobacterium tume-faclens klon C58C1 sa ubačenim A. rhizogenes A4 Ri plazmidom (pArA4b) koji produkuje korenove sposobne za autonoman rast na podlozi bez regulatora rastenja. Uspešna transformacija pokazana je PCR amplikacijom aih 1 i rol C sekvenci u uzorcima transformisanih korenova. Kulture transgenih korenova koje su se karakterisale intenzivnim bočnim grananjem, održavane su tokom 10 godina (90 i više subkultura) bez promena u morfologiji i fiziološkim svojstvima. Optimalni uslovi za rast ovih kultura bili su tečna podloga i 2% saharoza. Brz porast kultura zahtevao je male početne eksplantate i česta pasažiranja na svežu podlogu.nul

DETERMINATION OF CRITICAL SIZE OF CORROSION PIT ON MECHANICAL ELEMENTS IN HYDRO POWER PLANTS

Researchers in the field of fracture mechanics, predominantly developing appropriate solution algorithms for problems of solid bodies with cracks. Problems in mechanics generally, related with fracture and fatigue for solid bodies with various geometries of sharp notches, are studied to a much lesser extent. This situation can be explained by analytical difficulties arising in solving problems of elasticity theory for bodies with rounded notches. To solve problems of such class, starting from data on stress concentration in the rounded notch tip with a significant radius of curvature, simplified solutions with are therefore of great importance. Recent years, due to constant rise of computing power and development of numerical methods, re-evaluation of stress concentration factors from a viewpoint of theory of elasticity is present. This is mainly as a feedback from industry, which have requirements toward mega and nanostructures. Corrosion represents an important limitation to the safe and reliable use of many alloys in various industries. Pitting corrosion is a form of serious damage on metals surface such as high-strength aluminum alloys and stainless steel, which are susceptible to pitting when exposed to a corrosive attack in aggressive environments. This is particularly valid for dynamic loaded structures. The basic idea behind this paper is finding links between different scientific and engineering disciplines, which will enable useful level of applicability of existing knowledge. The subject of this paper is application of new method of determine length scale parameter for estimating the mechanistic aspect of corrosion pit under uniaxial/multiaxial high-cycle fatigue loadin

Dehydration-related changes of peroxidase and polyphenol oxidase activity in fronds of the resurrection fern Asplenium ceterach L.

Asplenium ceterach belongs to a group of poikilohydric ferns and it can recover uninjured from an almost completely dehydrated state. In our study, short term dehydration (24h) at four different water potentials, resulted in moderate water loss (partial desiccation) in fern tissue. The main phenolic acids represented in A. ceterach were chlorogenic (CGA) and caffeic acid (CA) and their content decreased during the dehydration process. For the first time, peroxidase (POD) and polyphenol oxidase (PPO) isoforms were determined in the rustyback fern. The results exhibit the presence of numerous anionic POD isoforms, with pI ranging from 4.4 to 5.8, but none of the cationic isoforms was detected. Two PPO isoforms were identified, one anionic with pI 6.3 and one cationic with pI of about 9.0. Short-term dehydration brought about a remarkable increase in POD and PPO activity using CGA as a substrate. Changes in enzyme activity and content of substrates during dehydration may play an important role in the adaptation of the rustyback fern to water deficit, and increase the overall plant resistance to stress conditions.nul