A study of global ecological adaptability and field selection practices of Panax ginseng / 中国中药杂志

Through the development of ecological suitability analysis of producing area and the selection criteria of farmland cultivation in the global range of ginseng, we aim to provide scientific basis for rational planning, production layout and standardized planting of farmland. We analyze the data based on the ecological factors from 271 sample plots of Panax ginseng, including both the traditional producing regions recorded in past dynasties medicinal works and the popular production regions in the world, using global geographic information system for medicinal plant(GMPGIS) developed by ICMM (Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences). We concluded that the suitable producing areas in global for P. ginseng mainly included America, Canada, China, Russia, Japan, North Korea, France, Italy, Ukraine, and South Korea. In addition, the suitable producing areas in China mainly included Heilongjiang, Jilin, Liaoning, Shanxi, Gansu, Hubei, Sichuan, Inner Mongolia, Shandong, and Shanxi. Besides, based on the references and the experience of ginseng-producing and our many years' work on the 1,000-hectare plantation of P. ginseng, we established a standard land selection protocol for cultivation of P. ginseng. The use of GMPGIS to select the most optimum ginseng production regions provides a new scientific basis for introduction, cultivation, tending, protection, cultivation normalization for P. ginseng and the standard land selection protocol would lay a solid foundation for the high quality P. ginseng production.

Effects of improving measures on soil micro-ecology and survival rate of ginseng in farmlands / 中国中药杂志

This study analysed the changes of the soil micro-ecology in the process of soil sterilization, green manure returning farmlands and fertilization. The methods of soil improvement was initially built which ensured the successful proceed of ginseng cultivation in farmlands. The soil chemical properties were analysed, the diversity and composition of bacterial community after soil sterilization, sterilization+green manure returning farmlands and sterilization+green manure returning farmlands+fertilization. The results exhibited that measures of soil improvement decreased the pH, increased soil fertility, declined the diversity of bacterial community and changed the composition of soil bacterial community. The comprehensive measures of sterilization+green manure returning farmlands+fertilization decreased the ginseng death rate compared to the control. Our data indicated that soil micro-ecological environment was changed by the treatments of soil sterilization, sterilization+green manure returning farmlands and sterilization+green manure returning farmlands+fertilization, and comprehensive measures improved the survival rate and guaranteed the development of ginseng cultivation in farmlands.

Colletotrichum orbiculare FAM1 Encodes a Novel Woronin Body-Associated Pex22 Peroxin Required for Appressorium-Mediated Plant Infection.

UNLABELLED: The cucumber anthracnose fungus Colletotrichum orbiculare forms specialized cells called appressoria for host penetration. We identified a gene, FAM1, encoding a novel peroxin protein that is essential for peroxisome biogenesis and that associates with Woronin bodies (WBs), dense-core vesicles found only in filamentous ascomycete fungi which function to maintain cellular integrity. The fam1 disrupted mutants were unable to grow on medium containing oleic acids as the sole carbon source and were nonpathogenic, being defective in both appressorium melanization and host penetration. Fluorescent proteins carrying peroxisomal targeting signals (PTSs) were not imported into the peroxisomes of fam1 mutants, suggesting that FAM1 is a novel peroxisomal biogenesis gene (peroxin). FAM1 did not show significant homology to any Saccharomyces cerevisiae peroxins but resembled conserved filamentous ascomycete-specific Pex22-like proteins which contain a predicted Pex4-binding site and are potentially involved in recycling PTS receptors from peroxisomes to the cytosol. C. orbiculare FAM1 complemented the peroxisomal matrix protein import defect of the S. cerevisiae pex22 mutant. Confocal microscopy of Fam1-GFP (green fluorescent protein) fusion proteins and immunoelectron microscopy with anti-Fam1 antibodies showed that Fam1 localized to nascent WBs budding from peroxisomes and mature WBs. Association of Fam1 with WBs was confirmed by colocalization with WB matrix protein CoHex1 (C. orbiculare Hex1) and WB membrane protein CoWsc (C. orbiculare Wsc) and by subcellular fractionation and Western blotting with antibodies to Fam1 and CoHex1. In WB-deficient cohex1 mutants, Fam1 was redirected to the peroxisome membrane. Our results show that Fam1 is a WB-associated peroxin required for pathogenesis and raise the possibility that localized receptor recycling occurs in WBs. IMPORTANCE: Colletotrichum orbiculare is a fungus causing damaging disease on Cucurbitaceae plants. In this paper, we characterize a novel peroxisome biogenesis gene from this pathogen called FAM1. Although no genes with significant homology are present in Saccharomyces cerevisiae, FAM1 contains a predicted Pex4-binding site typical of Pex22 proteins, which function in the recycling of PTS receptors from peroxisomes to the cytosol. We show that FAM1 complements the defect in peroxisomal matrix protein import of S. cerevisiae pex22 mutants and that fam1 mutants are completely defective in peroxisome function, fatty acid metabolism, and pathogenicity. Remarkably, we found that this novel peroxin is specifically localized on the bounding membrane of Woronin bodies, which are small peroxisome-derived organelles unique to filamentous ascomycete fungi that function in septal pore plugging. Our finding suggests that these fungi have coopted the Woronin body for localized receptor recycling during matrix protein import.

Peroxisome biogenesis factor PEX13 is required for appressorium-mediated plant infection by the anthracnose fungus Colletotrichum orbiculare.

Peroxisomes are ubiquitous organelles of eukaryotic cells that fulfill a variety of biochemical functions, including beta-oxidation of fatty acids. Here, we report that an ortholog of the Saccharomyces cerevisiae peroxisome biogenesis gene PEX13 is required for pathogenicity of Colletotrichum orbiculare. CoPEX13 was identified by screening random insertional mutants for deficiency in fatty acid utilization. Targeted knockout mutants of CoPEX13 were unable to utilize fatty acids as a carbon source. Expression analysis using green fluorescent protein fused to the peroxisomal targeting signals PTS1 and PTS2 revealed that the import machinery for peroxisomal matrix proteins was impaired in copex13 mutants. Appressoria formed by the copex13 mutants were defective in both melanization and penetration ability on host plants, had thin cell walls, and lacked peroxisomes. Moreover, the concentration of intracellular glycerol was lower in copex13 appressoria than those of the wild type. These findings indicate that fatty acid oxidation in peroxisomes is required not only for appressorium melanization but also for cell wall biogenesis and metabolic processes involved in turgor generation, all of which are essential for appressorium penetration ability.