Multifunctionalised benzoxazinones in the systems Oryza sativa–Echinochloa crus‐galli and Triticum aestivum–Avena fatua as natural‐product‐based herbicide leads

BACKGROUND: Fifteen novel derivatives of D‐DIBOA, including aromatic ring modifications and the addition of side chains in positions C‐2 and N‐4, had previously been synthesised and their phytotoxicity on standard target species (STS) evaluated. This strategy combined steric, electronic, solubility and lipophilicity requirements to achieve the maximum phytotoxic activity. An evaluation of the bioactivity of these compounds on the systems Oryza sativa–Echinochloa crus‐galli and Triticum aestivum–Avena fatua is reported here. RESULTS: All compounds showed inhibition profiles on the two species Echinochloa crus‐galli (L.) Beauv. and Avena fatua L. The most marked effects were caused by 6F‐4Pr‐D‐DIBOA, 6F‐4Val‐D‐DIBOA, 6Cl‐4Pr‐D‐DIBOA and 6Cl‐4Val‐D‐DIBOA. The IC₅₀ values for the systems Echinochloa crus‐galli–Oryza sativa and Avena fatua–Triticum aestivum for all compounds were compared. The compound that showed the greatest selectivity for the system Echinochloa crus‐galli–Oryza sativa was 8Cl‐4Pr‐D‐DIBOA, which was 15 times more selective than the commercial herbicide propanil (Cotanil‐35). With regard to the system Avena fatua–Triticum aestivum, the compounds that showed the highest selectivities were 8Cl‐4Val‐D‐DIBOA and 6F‐4Pr‐D‐DIBOA. The results obtained for 6F‐4Pr‐D‐DIBOA are of great interest because of the high phytotoxicity to Avena fatua (IC₅₀ = 6 µM , r² = 0.9616). CONCLUSION: The in vitro phytotoxicity profiles and selectivities shown by the compounds described here make them candidates for higher‐level studies. 8Cl‐4Pr‐D‐DIBOA for the system Echinochloa crus‐galli‐Oryza sativa and 6F‐4Pr‐D‐DIBOA for Avena fatua‐Triticum aestivum were the most interesting compounds. Copyright © 2010 Society of Chemical Industry     

Deep‐sequencing revealed Citrus bark cracking viroid (CBCVd) as a highly aggressive pathogen on hop

Newly emerging or re‐emerging diseases are a constant and significant threat to agricultural production, so prompt and accurate identification of the causative agents is required for rapid and appropriate disease management. Classical methods of pathogen detection can be successfully supplemented by next‐generation sequencing (NGS), whereby sequence analysis can help in the discovery of new or emerging diseases. In 2007, hop growers in Slovenia reported the appearance of severely stunted hop plants, a phenomenon that spread rapidly within hop gardens and among farms. Classical diagnostic methods were unable to detect a new pathogen; therefore, single step high‐throughput parallel sequencing of total RNA and small RNAs from plants with and without symptoms was employed to identify a novel pathogen. The sequences were assembled de novo and also mapped to reference genomes, resulting in identification of a novel sequence of Citrus bark cracking viroid (CBCVd) in the stunted hop plants. Furthermore, the presence of this novel pathogen on hop was confirmed by RT‐PCR analysis of 59 plants with symptoms from 15 hop gardens, representing the main outbreak locations identified by systematic disease monitoring, and small RNA Illumina sequencing of the bulked RNA sample. The high infectivity of the newly identified CBCVd was also confirmed by biolistic inoculation of two hop cultivars, which developed aggressive symptoms in controlled conditions. This study shows the feasibility of deep sequencing for the identification of causative agents of new diseases in hop and other plants.     

Expression of PDGFR-β and Kit in canine anal sac apocrine gland adenocarcinoma using tissue immunohistochemistry

Canine anal sac apocrine gland adenocarcinoma (ASAGAC) is an uncommon but highly invasive and metastatic malignancy. Toceranib phosphate (Palladia) is a receptor tyrosine kinase (RTK) inhibitor that targets several members of the split kinase RTK family. These membrane receptors are important for cell cycling, apoptosis and angiogenesis, all of which can contribute to carcinogenesis. The objective of this study was to evaluate archived, paraffin-embedded canine ASAGAC and normal canine anal sacs for immunohistochemical detection of Kit and platelet-derived growth factor receptor beta (PDGFR-β). Two of 77 neoplasms (2.6%) expressed Kit. Fifteen of the neoplasms (19.5%) were positive for PDGFR-β expression. None of the normal canine anal sac epithelium expressed Kit or PDGFR-β. Because of these results, further investigation should be considered to determine the role of RTKs in the clinical course and treatment of canine ASAGAC.