Lysophosphatidic acid (LPA) is a lipid messenger mediated by G protein-coupled receptors (LPAR1-6). It is involved in the pathogenesis of certain chronic inflammatory and autoimmune diseases. In addition, it controls the self-renewal and differentiation of stem cells. Recent research has demonstrated the close relationship between periodontitis and various diseases in the human body. However, the precise role of LPA in the development of periodontitis has not been studied. We identified that LPAR1 was highly expressed in human periodontal ligament stem cells (PDLSCs). In periodontitis-mimicking conditions with Porphyromonas gingivalis -derived lipopolysaccharide (Pg-LPS) treatment, PDLSCs exhibited a considerable reduction in the cellular viability and osteogenic differentiation potential, in addition to an increase in the inflammatory responses including tumor necrosis factor-α and interleukin-1β expression and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) activation. Of the various LPAR antagonists, pre-treatment with AM095, an LPAR1 inhibitor, showed a positive effect on the restoration of cellular viability and osteogenic differentiation, accompanied by a decrease in NF-κB signaling, and action against Pg-LPS. These findings suggest that the modulation of LPAR1 activity will assist in checking the progression of periodontitis and in its treatment.
Entomopathogenic fungi have been used as important part of integrated pest management program to control aphid. In particular, Beauveria bassiana was distributed throughout the world including temperate and tropical area, various habitats from alpine soil, desert soil to running water and both insect and plant. Especially the fungus has also been isolated from the surface and the interior of plants and act as natural control agent. Viability of fungi on the plant surface may be influenced by temperature, humidity, sunlight and plant type as well as fungal isolate. Persistence of treated fungal control agent on phylloplane and control efficacy may differ from environmental conditions and isolates. In this study, we investigated the persistence of an B. bassiana which is developing as prototype wettable powder to control cotton aphid, and the residual efficacy of the prototype on cucumber under three different greenhouse conditions.
Various insect pests and plant disease can outbreak in a field. For the effective control of pests and plant diseases during crop cultivation, farmers simultaneously or sequentially spray various eco-friendly agricultural materials (EFAM), chemical pesticides and microbial control agents on the same fields. It was reported that many agrochemicals are harmful to entomopathogenic fungi, especially some fungicides with broad spectrum activity that are routinely applied for the control of plant diseases. In addition, some pesticides may antagonize the potential insecticidal activity and efficiency of entomopathogenic fungi. Therefore, sometimes the utilization of fungal entomopathogen in forestry and agricultural production is limited because of the undesirable interference from some fungicides and pesticides. There is little research that examines the compatibility of these EFAMs with entomopathogenic fungi and the influence of EFAMs on the control efficacy of mycopesticides. We conducted a study of influence of pretreated eco-friendly agricultural materials on control efficacy of Isaria javanica isolate against sweet potato whitefly.
As ubiquitous organisms entomopathogenic fungi may natually occur within environment including phylloplanes and soil or deposite and survive for a while after spraying a fungal suspension to control insect pest. The existence of pathogenic fungi is a threat to arthropods foraging for food and oviposition sites. The detection and avoidance of pathogens is important for host survival, longevity and ultimate fitness. Although entomopathogenic fungi are ubiquitous worldwide and act as common natural enemies of many invertebrate species, very few studies have conducted abiut the detection and avoidance of pathogenic fungi by insect pest. We have studied that an insect pest can recognize a high virulence fungi on crop surface, avoid oviposition and don’t enter the field treated their pathogen.
Entomopathogenic fungus is a useful control agent to sucking type insect such as whitefly and aphid. The fungi are influenced by some environmental factors such as relative humidity, temperature and UV and cause slow and fluctuation in pest control efficacy. Especially, UV kills conidia or spores of entomopathogenic fungi and a mycopesticide using fungi has short control period in field. UV intensity changes from season to season. Survival rate of entomopathognic fungi treated may differ from seasons and will show different control efficacy. Therefore, we conducted a study to estimate the persistence of an Isaria javanica isolate, which was already reported as sweet potato whitefly control agent, in potted greenhouse soil planted different crops. The number of survival spore decreased gradually and differ from seasons.
Entomopathogenic fungi are natural enemies of insect pests and contribute to the natural regulation of their host populations. These fungal group are often used as active ingredients for microbial insect pest control. In addition, the potential antimicrobial effect by entomopathogenic fungi including Beauveria bassiana, Lecanicillium spp., and Isaria fumosorosea have recently been reported against fungal plant pathogens. Dual microbial control effects with entomopathogenic fungi against both aphids and cucumber powdery mildew had reported in Canada. In our previous studies we conducted bioassay with entomopathogenic fungi to develop dual microbial control agent which can control both aphid and fungal plant disease. We selected an Beauveria bassiana isolate which has high dual control effects against both cotton aphid, Aphis gossypii and sclerotinia rot, Sclerotinia sclerotiorum. In this study, we have tested the dual control efficacy of the B. bassiana isolate against cotton aphid and sclerotinia rot on whole potted cucumber plants. We found that the B. bassiana isolate protected the plant from cotton aphid and sclerotinia rot under laboratory condition.