The cloning, expression in vitro, and characterization of two aminopeptidase Ns (APN5s and APN2s) isolated from the midgut of Cry1Ac‐resistant (R) and susceptible (S) strains of Plutella xylostella larvae are presented in this paper. The deduced amino acid sequences of APN5s included C‐terminal GPI‐modification sites, the gluzincin aminopeptidase motif GATEN, and three N‐glycosylated sites; those of APN2s had no GPI‐modification sites, had gluzincin aminopeptidase motif GAMEN, and had four N‐glycosylated sites. O‐glycosylated sites were not predicted for either APN. Because APN2R and APN2S cDNAs contained the same nucleotides, only full‐length cDNAs encoding APN5R and APN5S were expressed in Trichoplusia ni cells. Far‐Western blotting showed that the expressed receptor APN5 bound to the Cry1Ac toxin. An enzyme‐specific activity experiment also showed that APN5 genes were expressed in T. ni cells. ELISA revealed no differences in the binding of expression proteins from the resistant and susceptible strain with Cry1Ac. © 2011 Wiley Periodicals, Inc. J Biochem Mol Toxicol 26:60–70 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/jbt.20401

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Sudden death syndrome (SDS) of soybean is a complex root rot disease caused by the semi-biotrophic fungus Fusarium solani (F. solani) and a leaf scorch disease; caused by toxins produced by pathogen in the roots. However, the mechanism of soybean resistant to F. solani is still poorly understood. Eighteen soybean cultivars were screened for SDS resistance, with one cultivar showing susceptibility and one cultivar showing resistance to F. solani infection. Histochemical analysis with diaminobenzidine (DAB) and Trypan blue staining indicated an accumulation of reactive oxygen species (ROS) and cell death in surrounding area of SDS which was higher in susceptible cultivar than in resistant cultivar. Furthermore, exogenous salicylic acid (SA) application also induced some level of resistance to F. solani by the susceptible cultivar. A biochemical study revealed that the activities of superoxide dismutase (SOD), peroxidase (POD), and enzymes involved in scavenging ROS, increased in susceptible cultivar after SDS infection. In addition, hydrogen peroxide (H2O2) and malondialdehyde (MDA) content also increased in the susceptible cultivar than in resistant cultivar. High-performance liquid chromatography (HPLC) analysis indicated that free and total salicylic acid (SA) content increased in the susceptible cultivar than in resistant cultivar. In addition, a real-time quantitative PCR analysis showed an accumulation of pathogen related (PR) genes in the resistant cultivar than in susceptible cultivar. Our results show that (i). F. solani infection can increase endogenous SA levels, antioxidase activities, ROS and cell death in susceptible soybean cultivar to induce resistance against Fusarium solani. (ii). F. solani infection induced the expression of SA marker genes in resistant soybean cultivar to enhance resistance.

Background: The Zoige alpine wetland is one of the most important wetlands in China because of its complex natural environment, abundant ecological resources, and unique climatic conditions. The ecology of soil fungi is poorly understood, and recent comprehensive reports on Trichoderma are not available for any region, including the Zoige alpine wetland ecological region in China. Our results may be used as a reference for a greater understanding of soil microorganism at various ecological regions, ecological rehabilitation and reconstruction and as microbial resources. Results: One hundred soil samples were collected from different soil types and soil layers in Zoige alpine wetland ecological regions in 2013. Using the traditional suspension plating method, a total of 80 Trichoderma strains were isolated. After a preliminary classification of morphological characteristics and the genes glyceraldehyde-3-phosphate dehydrogenase (gpd), 57 strains were representatively selected and eventually identified as seven species via phylogenetic analyses of multilocus sequences based on the genes transcription elongation factor 1 alpha (tef1), encoding RNA polymerase II subunit B (rpb2) and ATP citrate lyase (acl1). Among them, Trichoderma harzianum was the dominant species and had the highest isolation frequency (23%) in this zone, while Trichoderma polysporum and Trichoderma pyramidale were rare species, with isolation frequencies of less than 1%.Conclusions: Our detailed morphological observation and molecular phylogenetic analyses support the recognition of Trichoderma zoigense was described for the first time as a new species.