Functional insights of three RING-finger peroxins in the life cycle of the insect pathogenic fungus Beauveria bassiana.

Peroxisomes play important roles in fungal physiological processes. The RING-finger complex consists of peroxins Pex2, Pex10, and Pex12 and is essential for recycling of receptors responsible for peroxisomal targeting of matrix proteins. In this study, these three peroxins were functionally characterized in the entomopathogenic fungus Beauveria bassiana (Bb). These three peroxins are associated with peroxisomes, in which BbPex2 interacted with BbPex10 and BbPex12. Ablation of these peroxins did not completely block the peroxisome biogenesis, but abolish peroxisomal targeting of matrix proteins via both PTS1 and PTS2 pathways. Three disruptants displayed different phenotypic defects in growth on nutrients and under stress conditions, but have similar defects in acetyl-CoA biosynthesis, development, and virulence. Strikingly, BbPex10 played a less important role in fungal growth on tested nutrients than other two peroxins; whereas, BbPex2 performed a less important contribution to fungal growth under stresses. This investigation reinforces the peroxisomal roles in the lifecycle of entomopathogenic fungi and highlights the unequal functions of different peroxins in peroxisomal biology.

Comparative transcriptome analysis reveals differences in gene expression in whitefly following individual or combined applications of Akanthomyces attenuatus (Zare & Gams) and matrine.

BACKGROUND: Bemisia tabaci Gennadius (Hemiptera: Aleyrodidae) is a serious pest of crops in different regions of the world. Our recent studies on the joint application of Akanthomyces attenuatus (a pathogenic insect fungus) and matrine (a botanical insecticide) against B. tabaci have shown promising results. Using RNA sequencing (RNA-Seq), we identified differentially expressed genes involved in whitefly responses to single or mixed applications of A. attenuatus and matrine. METHODS: In this study, we compared the transcriptome profiles of B. tabaci treated with individual and combined treatments of A. attenuatus and matrine to determine variations in gene expression among whiteflies in response to different treatments. RESULTS: Transcriptomic data analysis showed differential expression of 71, 1194, and 51 genes in response to A. attenuatus (BtA), matrine (BtM), and A. attenuatus + matrine (BtAM) treatment, respectively. A total of 65 common differentially expressed genes (DEGs) were identified between whiteflies treated with A. attenuatus (BtA) and matrine (BtM). A comparison of DEGs across the three treatments (BtA, BtM, and BtAM) revealed two common DEGs. The results also revealed that AMPK signaling, apoptosis, and drug metabolism pathways are likely involved in whitefly defense responses against A. attenuatus and matrine infection. Furthermore, a notable suppression of general metabolism and immune response genes was observed in whiteflies treated with A. attenuatus + matrine (BtAM) compared to whiteflies treated with individual A. attenuatus (BtA) or matrine (BtM) treatments. CONCLUSION: Dynamic changes in the number of differentially expressed genes were observed in B. tabaci subjected to different treatments (BtA, BtM, and BtAM). To the best of our knowledge, this is the first report on the molecular interactions between whitefly and individual or combined treatments of A. attenuatus and matrine. These results will further improve our knowledge of the infection mechanism and complex biochemical processes involved in the synergistic action of A. attenuatus and matrine against B. tabaci.

Comparative proteomic analysis reveals insights into the response of Cryptolaemus montrouzieri to bottom-up transfer of cadmium and lead across a multi-trophic food chain.

Contamination of agro-ecosystems with heavy metals can affect the development and reproduction of insect natural enemies. This study reports a detailed Tandem Mass Tag based quantitative proteomic analysis of underlying mechanisms responsible for stress response of Cryptolaemus montrouzieri against heavy metals (cadmium (Cd) and lead (Pb)) transported across a multi-trophic food chain. A total of 6639 proteins were detected under Cd as well as Pb stress. In Pb versus the control cluster, 69 proteins (28 up-regulated and 41 down-regulated) were differentially expressed whereas 268 proteins were differentially expressed under Cd versus the control cluster, having 198 proteins up-regulated and 70 down-regulated proteins. The analysis of differentially expressed proteins showed that 27 proteins overlapped in both clusters representing the core proteome to Pb and Cd stress. The bioinformatics analysis demonstrated that these proteins were mapped to 57 and 99 pathways in Pb versus control and Cd versus control clusters, respectively. The functional classification by COG, GO and KEGG databases showed significant changes in protein expression by C. montrouzieri under Pb and Cd stress. The heavy metal stress (Pb and Cd) induced significant changes in expression of proteins like hexokinase (HK), succinyl-CoA, trypsin like proteins, cysteine proteases, cell division cycle proteins, and yellow gene proteins. The results provide detailed information on the protein expression levels of C. montrouzieri and will serve as basic information for future proteomic studies on heavy metal responses of insect predators within a multi-trophic food chain.

Synthesis of Cordyceps fumosorosea-Biochar Nanoparticles and Their Effects on Growth and Survival of Bemisia tabaci (Gennadius).

Nanotechnology can offer an environmentally sustainable alternative to synthetic chemicals for pest management. Nano-formulations of different microbial pest control agents have been effective against several insect pests. Synthesis of Cordyceps fumosorosea-biochar (BC) nanoparticles and their bio-efficacy against Bemisia tabaci was observed during this study. The characterization of C. fumosorosea-BC nanoparticles through different analytical techniques showed successful synthesis of nanoparticles. UV spectroscopy showed a characteristic band of surface plasmon between 350 and 400 nm; SEM images confirmed the synthesis of spherical shaped nanoparticles; X-ray diffractogram showed strong peaks between 2θ values of 20°-25°; and atomic force microscopy (AFM) analysis revealed particle size of 49.151 nm. The bioassay studies demonstrated that different concentrations of C. fumosorosea-BC nanoparticles caused significant reduction in hatchability of B. tabaci eggs as well as survival of immatures emerging from treated eggs when compared with controls. The results also revealed that C. fumosorosea-BC nanoparticles were highly pathogenic against 2nd and 3rd instar nymphs and pupae of B. tabaci having LC50 values of 6.80, 7.45, and 8.64 ppm, respectively. The LT50 values for 20 ppm concentration of C. fumosorosea-BC nanoparticles against 2nd and 3rd instar nymphs, and pupae of B. tabaci were 3.25 ± 0.29, 3.69 ± 0.52, and 4.07 ± 0.51 days, respectively. These findings suggest that C. fumosorosea-BC nanoparticles can potentially be used in biorational B. tabaci management programs.

Pseudogene MSTO2P enhances hypoxia-induced osteosarcoma malignancy by upregulating PD-L1.

Hypoxia has been shown to be related to osteosarcoma development and progression. Pseudogene MSTO2P was reported to be dysregulated in hepatocellular carcinoma and lung cancer. However, the mechanism by which MSTO2P-modulated osteosarcoma remains unclear. MSTO2P and PD-L1 expression levels were examined by RT-qPCR and westernblot. Tumor cell invasion was determined by tranwell assay. EMT process was probed by determining E-cadherin and Vimentin levels. Soft agar assay was used to examine anchorage-independent growth of osteosarcoma cells. In vivo tumor growth was measured by xenografting tumor experiment. Hypoxia treatment promoted cell growth, invasion and EMT of osteosarcoma cells. MSTO2P knockdown led to attenuated cell growth, invasion and EMT of osteosarcoma cells under hypoxia condition. More interestingly, our data revealed that MSTO2P was positively associated with tumor growth in immunodeficient mice and human clinical tissues. PD-L1 was shown to act as a key effector for MSTO2P-regulated osteosarcoma progression under hypoxia condition. In conclusion, we unravel a novel mechanism for explaining MSTO2P-involved osteosarcoma progression under hypoxia condition, which will facilitate development of potential diagnostic and therapeutical strategies for osteosarcoma.

Endophytic Isolates of Cordyceps fumosorosea to Enhance the Growth of Solanum melongena and Reduce the Survival of Whitefly (Bemisia tabaci).

This study reports the effects of seed treatment with Cordyceps fumosorosea on seed germination, growth, colonization of eggplant (Solanum melongena), and growth of Bemisia tabaci (feeding on fungal colonized eggplant leaves). Germination rates of eggplant seeds were similar among different treatments. The growth parameters such as root length, shoot length, and number of leaves) differed significantly after 15, 30, and 60 days of seed treatment. The total dry weight of eggplant in response to treatment with C. fumosorosea isolates increased significantly when compared with the control. Both isolates of C. fumosorosea colonized different plant tissues, although the extent of colonization decreased during the experimental period. The colonization of eggplants by both C. fumosorosea isolates resulted in a significant reduction of B. tabaci incidence. This study possibly provides the first report of increased plant growth and increased insect mortality in eggplants inoculated with C. fumosorosea isolates.