Evaluation of fungicides to control potato late blight (Phytophthora infestans) in the plains of Nepal

Fungicide application is an effective management option to control late blight of potato (caused by Phytophthora infestans). Field experiments were conducted to evaluate the efficacy of recently introduced and previously used fungicides on late blight management and potato yields in the western plains of Nepal in 2015 and 2016 crop seasons. Fungicides and a non-treated control (NTC) were replicated three times in a randomized block design planted with late blight susceptible cultivar Cardinal. Chlorothalonil, copper oxychloride, dimethomorph, fenamidone + mancozeb, mancozeb and metalaxyl were sprayed in 2015. In 2016, carbendazim was used instead of chlorothalonil. The area under disease progress curve (AUDPC) was consistently reduced in years by dimethomorph (90% and 65% in 2015 and 2016, respectively), fenamidone + mancozeb (68% and 62%) and mancozeb (40% and 47%) compared with the NTC. Similarly, tuber yield was increased with the application of dimethomorph (266% and 146% in 2015 and 2016, respectively), fenamidone + mancozeb (211% and 155%) and mancozeb (136% and 116%) compared with the NTC. Chlorothalonil reduced AUDPC by 43% and increased tuber yield by 170% in 2015. Other fungicides either had inconsistent results or did not reduce late blight severity and consequent effects on potato yield. The overall benefit–cost ratio was highest for dimethomorph in both years. These results show efficacy of dimethomorph, fenamidone + mancozeb and mancozeb in reducing late blight severity and increasing potato tuber yield in the plains of Nepal.     

Estimating occupancy of Chinese pangolin (Manis pentadactyla) in a protected and non‐protected area of Nepal

Chinese pangolin is the world's most heavily trafficked small mammal for luxury food and traditional medicine. Although their populations are declining worldwide, it is difficult to monitor their population status because of its rarity and nocturnal behavior. We used site occupancy (presence/absence) sampling of pangolin sign (i.e., active burrows) in a protected (Gaurishankar Conservation Area) and non‐protected area (Ramechhap District) of central Nepal with multiple environmental covariates to understand factors that may influence occupancy of Chinese pangolin. The average Chinese pangolin occupancy and detection probabilities were  ± SE = 0.77 ± 0.08;  ± SE = 0.27 ± 0.05, respectively. The detection probabilities of Chinese pangolin were higher in PA (  ± SE = 0.33 ± 0.03) than compared to non‐PA (  ± SE = 0.25 ± 0.04). The most important covariates for Chinese pangolin detectability were red soil (97%), food source (97.6%), distance to road (97.9%), and protected area (97%) and with respect to occupancy was elevation (97.9%). We recommended use of remote cameras and potentially GPS collar surveys to further investigate habitat use and site occupancy at regular intervals to provide more reliable conservation assessments.     

Identification and characterization of a novel enzyme related to the synthesis of PUFAs derived from <Emphasis Type="Italic">Thraustochytrium aureum</Emphasis> ATCC 34304

In Thraustochytrids, Thraustochytrium aureum ATCC 34304 was able to produce high levels of several polyunsaturated fatty acids. In the present study, a novel gene encoding protein was cloned from the DHA rich microbe, T. aureum ATCC 34304. The functional analysis of a novel gene was demonstrated by its heterologous expression in Pichia pastoris. The gene was able to synthesize C20 and C22 PUFAs, as well as, to mediate different elongations (Δ9, Δ6, and Δ5) and one Δ5 desaturation activities. The conversion rates of the Δ9 elongation (n-3) and Δ5 desaturation products were found to be higher in response to the novel enzyme than the controls (TaElo and Tad5, respectively). The other Δ9 elongation (n-6) and Δ5 elongation products were slightly lower than those of the control (TaElo). The full length of the 1,374 bp gene contained 458 amino acids that showed very limited homology with desaturases and elongases from various organisms. In addition, the rate of synthesis of PUFAs was evaluated at temperatures ranging from 10 to 30°C. The elongation products were found to decrease dramatically and the desaturation products were found to increase dramatically at 10°C. TaNE was confirmed to be a multifunctional enzyme with higher activity towards Δ6 elongations than Δ9, Δ5 elongations, and Δ5 desaturation.     

The novel ORFV protein ORFV113 activates LPA-p38 signaling

Viruses have evolved mechanisms to subvert critical cellular signaling pathways that regulate a wide range of cellular functions, including cell differentiation, proliferation and chemotaxis, and innate immune responses. Here, we describe a novel ORFV protein, ORFV113, that interacts with the G protein-coupled receptor Lysophosphatidic acid receptor 1 (LPA₁). Consistent with its interaction with LPA₁, ORFV113 enhances p38 kinase phosphorylation in ORFV infected cells in vitro and in vivo, and in cells transiently expressing ORFV113 or treated with soluble ORFV113. Infection of cells with virus lacking ORFV113 (OV-IA82Δ113) significantly decreased p38 phosphorylation and viral plaque size. Infection of cells with ORFV in the presence of a p38 kinase inhibitor markedly diminished ORFV replication, highlighting importance of p38 signaling during ORFV infection. ORFV113 enhancement of p38 activation was prevented in cells in which LPA₁ expression was knocked down and in cells treated with LPA₁ inhibitor. Infection of sheep with OV-IA82Δ113 led to a strikingly attenuated disease phenotype, indicating that ORFV113 is a major virulence determinant in the natural host. Notably, ORFV113 represents the first viral protein that modulates p38 signaling via interaction with LPA₁ receptor.