Toxoplasma gondii virulence prediction using hierarchical cluster analysis based on coding sequences (CDS) of sag1, gra7 and rop18

Toxoplasma gondii consists of three genotypes, namely genotype I, II and III. Based on its virulence, T. gondii can be divided into virulent and avirulent strains. This study intends to evaluate an alternative method for predicting T. gondii virulence using hierarchical cluster analysis based on complete coding sequences (CDS) of sag1, gra7 and rop18 genes. Dendrogram was constructed using UPGMA with a Kimura 80 nucleotide distance measurement. The results showed that the prediction errors of T. gondii virulence using sag1, gra7 and rop18 were 7.41%, 6.89% and 9.1%, respectively. Analysis based on CDS of gra7 and rop18 was able to differentiate avirulent strains into genotypes II and III, whereas sag1 failed to differentiate.     

Responses to graded replacement of urea by maize steep liquor in diets for intensively fed lambs for meat production

Urea is a common ingredient of the diets of intensively fed lambs, but is increasingly required for industrial processes. Maize steep liquor (MSL) is a by-product of maize grain degradation to produce starch that may be a suitable replacement. Fifty growing lambs were fed on equinitrogenous diets in which between 0% and 80% of the urea was replaced by MSL; their growth and metabolism were recorded over 70 days. Increasing replacement of urea by MSL increased feed intake and nutrient digestibilities, leading to increased growth rates, more efficient feed conversion, and increased nitrogen retention. Concentrations of triiodothyroxin, thyroxin, glucose, and methionine were increased by replacement of urea by liquor, and plasma urea was reduced. This study suggests that MSL is a suitable replacement for up to 80% of urea in the diet of rapidly growing lambs.     

Virulence of Verticillium lecanii (Z.) against cereal aphids; does timing of infection affect the performance of parasitoids and predators?

BACKGROUND: Entomopathogenic fungi such as Verticillium lecanii (Z.) (Mycotal^®) are used for pest control as an alternative to chemical control. In this study, the effect of V. lecanii on cereal aphids is assessed. In addition, an investigation is carried out to determine whether the use of V. lecanii affects the performance of two natural enemies of aphids, the predator Harmonia axyridis (P.) and the parasitoid Aphidius colemani (V.), in no‐choice experiments under laboratory conditions. RESULTS: The number of Rhopalosiphum padi (L.) and Sitobion avenae (F.) killed was increased by increasing the concentration of V. lecanii. The timing of application of fungus to aphids affected the efficacy of other biocontrol agents, a parasitoid and a predator. Parasitation by A. colemani (V.) in both cereal aphids (S. avenae and R. padi) was not affected by V. lecanii when aphids were first treated with V. lecanii and then exposed to A. colemani. The emergence of adults from parasitised mummies was, however, lower in infected aphids than in uninfected aphids when the aphids were first exposed to the parasitoids and then treated with fungus. The female sex ratio in the emerging adults was lower in V. lecanii‐treated aphids in both species. When aphids were first treated with V. lecanii, 72 h before predation, fewer aphids of both species were consumed by H. axyridis (P.). CONCLUSION: Use of entomopathogenic fungus as a biological control agent could be a complementary strategy in an integrated pest management programme against cereal aphids, but it can reduce the efficiency of other biocontrol agents (parasitoids and predators) when applied simultaneously. © 2012 Society of Chemical Industry     

Evaluation of cell wall preparations for proteomics: a new procedure for purifying cell walls from Arabidopsis hypocotyls

Background  

The ultimate goal of proteomic analysis of a cell compartment should be the exhaustive identification of resident proteins; excluding proteins from other cell compartments. Reaching such a goal closely depends on the reliability of the isolation procedure for the cell compartment of interest. Plant cell walls possess specific difficulties: (i) the lack of a surrounding membrane may result in the loss of cell wall proteins (CWP) during the isolation procedure, (ii) polysaccharide networks of cellulose, hemicelluloses and pectins form potential traps for contaminants such as intracellular proteins. Several reported procedures to isolate cell walls for proteomic analyses led to the isolation of a high proportion (more than 50%) of predicted intracellular proteins. Since isolated cell walls should hold secreted proteins, one can imagine alternative procedures to prepare cell walls containing a lower proportion of contaminant proteins.     

Effects of steam-treated rice straw feeding on growth,digestibility, and plasma volatile fatty acids of goats under different housing systems

In order to use rice straw as forage in livestock feeding, the effects of steam-treated rice straw (at 15.5 kgf/cm² for 120 s) feeding on growth performance, plasma volatile fatty acid profile, and nutrient digestibility of goats were determined. Twenty male goats (18.69?±?0.34 kg) were used in an 84-day trial. The goats were divided into four groups of five goats each to receive steam-treated (STRS) or untreated (UTRS) rice straw diet under closed house (CH) and open house (OH) systems. The results revealed that the goats fed with STRS had significantly higher dry matter (DM), organic matter (OM), crude protein (CP), neutral detergent fiber (NDF), and acid detergent fiber (ADF) digestibility; similarly, the average daily weight gain and feed conversion ratio were higher for STRS groups under both CH and OH systems than those for UTRS. The plasma protein and insulin in STRS and cholesterol in UTRS groups was higher (P?P?>?0.05) at 30 days. The plasma amylase, lipase, T₃, T₄ and glucagon at 30 and 60 days were not different (P?>?0.05) among the groups. The plasma acetate, propionate, butyrate, and total volatile fatty acid were higher (P?P?>?0.05) on these parameters. It could be concluded that steam treatment of rice straw at 15.5 kgf/cm² for 120 s increased apparent nutrient digestibility, hence increased the growth and feed efficiency of growing goats.     

Effect of γ (Gamma)-radiation on the physico-mechanical properties of grafted jute fabric reinforced polypropylene (PP) composites

The bleached jute fabric (BJF) reinforced polypropylene (PP) composites with various contents of acrylic acid (AA)-treated BJF and un-AA-treated BJF were fabricated by compression moulding method at 190 °C. The AA-grafted BJF reinforced PP composites were then irradiated by γ-ray at various doses. The mechanical properties of neat PP (N-P), ungrafted-BJF and PP composites (UG-BJFPC), AA-grafted-BJF and PP composites (AA-BJFPC) and γ-ray cum AA-grafted-BJF and PP composites (γAA-BJFPC) show maximum tensile strength (TS) of 30, 46, 47 and 51 MPa, maximum flexural strength (FS) of 34, 49, 50 and 54 MPa and maximum Young’s modulus (E) of 280, 428, 436, and 680 MPa, respectively. The increase of TS, FS and E from UG-BJFPC are 2 %, 2 %, and 2 % for AA-BJFPC and 11 %, 10 % and 59 % for γAA-BJFPC. The TS, FS and E are found to increase with radiation dose up to 500Krad and then decrease. The water absorption (WA) for UG-BJFPC, AA-BJFPC and γAA-BJFPC is respectively about 14, 10 and 9 %, indicating a gradual development of hydrophobic character of the composites first by AA-treatment and then by γ-ray-treatment. AA treatment on jute fabric and gamma irradiation on composite result in significant change of morphology of the jute fabric composites surface and better mechanical bonding between fabric and polymer matrix, as a result improved mechanical properties are found.     

Rhizosphere microbiomes can regulate plant drought tolerance

Beneficial root-associated rhizospheric microbes play a key role in maintaining host plant growth and can potentially allow drought-resilient crop production. The complex interaction of root-associated microbes mainly depends on soil type, plant genotype, and soil moisture. However, drought is the most devastating environmental stress that strongly reduces soil biota and can restrict plant growth and yield. In this review, we discussed our mechanistic understanding of drought and microbial response traits. Additionally, we highlighted the role of beneficial microbes and plant-derived metabolites in alleviating drought stress and improving crop growth. We proposed that future research might focus on evaluating the dynamics of root-beneficial microbes under field drought conditions. The integrative use of ecology, microbial, and molecular approaches may serve as a promising strategy to produce more drought-resilient and sustainable crops.     

Build up of patches caused by Rhizoctonia solani

Rhizoctonia solani is a complex species that is composed of different anastomosis groups (AG). Although these different AGs show differences in their host ranges, generally R. solani is a phytopathogenic species with a wide spectrum of hosts. It has the ability to grow as a saprotroph, which further complicates its behaviour as a parasite. The losses caused by R. solani are very important and need a sustainable management strategy. The patchy appearance of the disease caused by this pathogen is well-known. The patches show within and between season dynamics. The factors which affect the spread of the disease can be grouped into three main categories: host plant, pathogen and environment. However, each of the categories in its detail may depend on or react with the other categories. There are a number of factors that may be involved in dynamics of patches. These potential mechanisms are discussed. It is essential to know about the mechanisms involved to develop an effective control strategy. Although more work is needed to investigate different mechanisms of parasitism deployed by different AGs in different hosts, it seems that many mechanisms external to the host are operating at the same time which necessitates an integrative research approach to study and control the diseases caused by R. solani.