Plant Copper Amine Oxidases: Key Players in Hormone Signaling Leading to Stress-Induced Phenotypic Plasticity

Polyamines are ubiquitous, low-molecular-weight aliphatic compounds, present in living organisms and essential for cell growth and differentiation. Copper amine oxidases (CuAOs) oxidize polyamines to aminoaldehydes releasing ammonium and hydrogen peroxide, which participates in the complex network of reactive oxygen species acting as signaling molecules involved in responses to biotic and abiotic stresses. CuAOs have been identified and characterized in different plant species, but the most extensive study on a CuAO gene family has been carried out in Arabidopsis thaliana. Growing attention has been devoted in the last years to the investigation of the CuAO expression pattern during development and in response to an array of stress and stress-related hormones, events in which recent studies have highlighted CuAOs to play a key role by modulation of a multilevel phenotypic plasticity expression. In this review, the attention will be focused on the involvement of different AtCuAOs in the IAA/JA/ABA signal transduction pathways which mediate stress-induced phenotypic plasticity events.     

外源乙烯对黄瓜幼苗根系生长及内源多胺含量的影响

精确控制营养液溶氧浓度和外源乙烯浓度,研究了黄瓜幼苗根系在低氧水培时的生长情况以及PAs含量的变化。结果表明,外源乙烯对根际低氧逆境下黄瓜幼苗根系的生长有抑制作用,虽然根径增粗,含水量增加,但根系的总根数、总表面积、总体积、干重和鲜重都有所减少,随着乙烯浓度的增加,抑制作用增强;外源乙烯对根际低氧逆境下黄瓜幼苗根系PAs含量有着明显的拮抗作用,外源乙烯使根际低氧逆境下黄瓜幼苗根系的伤害症状加重。     

The role of castor oil in epoxy and polyamide systems for coating and adhesive application

Summary  Over the past few years, the challenges of globalisation, consolidation and economical point of view have meant that manufacturers of epoxy formulations have to constantly improve their capability to meet the needs of customers. An active area for advancement is that of epoxy and polyamide resin with castor oil. Generally, people working in the coating industries are familiar with castor oil, but this paper provides information on the new use of castor oil in epoxy and polyamide resin. This novel product (castor oil-modified epoxy resin/castor oil-modified polyamide) provides a previously unattainable combination and improved flexibility and toughness to a variety of ambient cure applications. This communication will review the performance of these castor oil-modified epoxy and polyamide resin surface coatings and adhesives. Based on the results of this study, these systems offer some advantages without much affecting the traditional properties of epoxy and polyamide resin in a variety of applications.     

Endogenous Polyamines and Ethylene Biosynthesis in Relation to Germination of Osmoprimed Brassica napus Seeds under Salt Stress

Currently, seed priming is reported as an efficient and low-cost approach to increase crop yield, which could not only promote seed germination and improve plant growth state but also increase abiotic stress tolerance. Salinity represents one of the most significant abiotic stresses that alters multiple processes in plants. The accumulation of polyamines (PAs) in response to salt stress is one of the most remarkable plant metabolic responses. This paper examined the effect of osmopriming on endogenous polyamine metabolism at the germination and early seedling development of Brassica napus in relation to salinity tolerance. Free, conjugated and bound polyamines were analyzed, and changes in their accumulation were discussed with literature data. The most remarkable differences between the corresponding osmoprimed and unprimed seeds were visible in the free (spermine) and conjugated (putrescine, spermidine) fractions. The arginine decarboxylase pathway seems to be responsible for the accumulation of PAs in primed seeds. The obvious impact of seed priming on tyramine accumulation was also demonstrated. Moreover, the level of ethylene increased considerably in seedlings issued from primed seeds exposed to salt stress. It can be concluded that the polyamines are involved in creating the beneficial effect of osmopriming on germination and early growth of Brassica napus seedlings under saline conditions through moderate changes in their biosynthesis and accumulation.     

N,N′,N″-三(异丙基)-1,4,7-三氮杂环壬烷的合成改进

在无水碳酸钾存在下,以1,4,7-三氮杂环壬烷和2-溴丙烷为原料合成了标题化合物,与文献方法相比,产物处理简单,产率高达99%。     

Enhancing crop yield with the use of N‐based fertilizers co‐applied with plant hormones or growth regulators

Crop yield, vegetative or reproductive, depends on access to an adequate supply of essential mineral nutrients. At the same time, a crop plant's growth and development, and thus yield, also depend on in situ production of plant hormones. Thus optimizing mineral nutrition and providing supplemental hormones are two mechanisms for gaining appreciable yield increases. Optimizing the mineral nutrient supply is a common and accepted agricultural practice, but the co‐application of nitrogen‐based fertilizers with plant hormones or plant growth regulators is relatively uncommon. Our review discusses possible uses of plant hormones (gibberellins, auxins, cytokinins, abscisic acid and ethylene) and specific growth regulators (glycine betaine and polyamines) to enhance and optimize crop yield when co‐applied with nitrogen‐based fertilizers. We conclude that use of growth‐active gibberellins, together with a nitrogen‐based fertilizer, can result in appreciable and significant additive increases in shoot dry biomass of crops, including forage crops growing under low‐temperature conditions. There may also be a potential for use of an auxin or cytokinin, together with a nitrogen‐based fertilizer, for obtaining additive increases in dry shoot biomass and/or reproductive yield. Further research, though, is needed to determine the potential of co‐application of nitrogen‐based fertilizers with abscisic acid, ethylene and other growth regulators. © 2014 Society of Chemical Industry     

Inverted emulsion polymerization route to polyaniline‐3D nanofiber network using sulfonated‐p‐cresol as novel dopant

Sulfonated‐p‐cresol (SPC) was used as novel dopant for the first time in the synthesis of polyaniline in 3D nanofiber networks (PANI‐3D). Polyaniline in 3D nanofiber network was prepared using organic solvent soluble benzoyl peroxide as oxidizing agent in presence of SPC and sodium lauryl sulfate (SLS) surfactant via inverted emulsion polymerization pathway. The influence of synthesis conditions such as the concentration of the reactants, stirring/static condition, and temperature etc., on the properties and formation of polyaniline nanofiber network were investigated. Polyaniline in 3D nanofiber network with 40–160 nm (diameter), high yield (134 wt % with respect to aniline used), and reasonably good conductivity (0.1 S/cm) was obtained in 24 h time. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Easy preparation of crosslinked polymer films from polyoxyalkylene diamine and poly(styrene–maleic anhydride) for electrostatic dissipation

The curing reaction of polyoxyalkylene diamine and poly(styrene–maleic anhydride) was able to produce polymer films that were hygroscopic in nature. The process involved the formation of an imine intermediate by dissolving the diamine monomers in a ketone solvent, followed by instant casting into films before the solution self‐cured into a gel product. Hydrophilic films were formed by the fast reaction of amine with anhydride while evaporating the solvent under vacuum. The resulting films exhibited dissipation of electrostatic charges over a wide range, from 10^9.4 to 10^4.1 Ω/sq surface resistivity. The low resistivity was attributed to the functionality of hydrophilic polyoxyethylene (POE), which was able to adsorb moisture and optionally to the added metal ion salts. Furthermore, the slightly crosslinked network prevented POE from having crystallinity and rendered the films solvent resistant, thermally stable, and suitable for applications as antistatic and polymeric electrolytes. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 716–723, 2007     

Effects of Postharvest Putrescine Treatment on Extending Shelf Life and Reducing Mechanical Damage in Apricot

ABSTRACT: Apricots ( Prunus armeniaca L. cv Mauricio) harvested at commercial ripening stage were treated with putrescine (1 mM), then mechanically damaged with a 25 N force and stored at 10 °C for 6 d. Putrescine treatment increased fruit firmness and reduced the bruising zones caused by the mechanical damage. Putrescine-treated fruits (both damaged and nondamaged) showed different physiological behavior than controls. Color change, weight loss, ethylene emission, and respiration rate were reduced in putrescine-treated fruits. The most remarkable effect of the mechanical damage was the significant increase in spermidine concentrations found after the compression in control apricots, which could be considered as a physiological marker of mechanical damage.