Molecular mechanisms involved in pseudomonas biocontrol

假单胞菌生物防治的分子机制

• 批准号: 249559-2007
• 负责人: DeKievit, Teresa
• 金额: $ 2.77万
• 依托单位: University of Manitoba
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2008
• 资助国家: 加拿大
• 起止时间: 2008-01-01 至 2009-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=394370
• 关键词: Molecular; mechanisms; involved; pseudomonas; biocontrol

Modern day crop protection relies heavily on the use of chemical pesticides. Increasing public concern over the risk these chemicals pose to the environment and human health has led to a search for a safer alternatives. Some bacteria naturally present in soil are able to inhibit the ability of fungi to cause disease in plants. As these bacteria do not cause disease in humans or other animals, they are an environmentally friendly alternative to chemical pesticides. Sclerotinia sclerotiorum is a fungus that causes devastating losses in canola as well as over 400 other crop species. Two bacteria have been isolated from the environment, Pseudomonas chlororaphis strain PA23 and Pseudomonas sp. DF41 that are able to control the growth of this fungus and protect canola from disease. Unfortunately in the past, commercial use of bacteria to manage crop diseases has met with limited success. This is most likely due to fluctuations in environmental conditions, which cause variations in the amount of antifungal products produced by the beneficial bacteria. Strains PA23 and DF41 produce antibiotics and enzymes that control fungal growth, and therefore disease. Our research is focused on understanding how genes responsible for disease control (biocontrol) are regulated. We will investigate how a new regulator of gene expression, called PtrA, controls production of antibiotics and enzymes in PA23 and DF41. In addition, we will look at the manner in which these antibiotics are exported outside of the bacterial cell. The chemical structure of the antibiotic produced by DF41 is currently not known, so we will deduce its structure. In the environment nutrients are scarce; consequently, we will investigate the impact of limited food availability on expression of genes and products required for disease suppression. These studies will shed light on how PA23 and DF41 are able to inhibit fungal growth. This will enable us to use these two bacteria as pesticide alternatives in a consistent and predictable manner.

现代作物保护严重依赖于化学农药的使用。 公众日益关注这些化学品对环境和人类健康构成的风险，因此寻求更安全的替代品。土壤中天然存在的一些细菌能够抑制真菌在植物中引起疾病的能力。由于这些细菌不会引起人类或其他动物的疾病，它们是化学杀虫剂的环保替代品。 核盘菌（Sclerotinia sclerotiorum）是一种真菌，可导致油菜以及400多种其他作物物种的毁灭性损失。 已经从环境中分离出两种细菌，绿针假单胞菌菌株PA 23和假单胞菌属DF 41，它们能够控制这种真菌的生长并保护油菜免受疾病的侵害。不幸的是，在过去，商业上使用细菌来管理作物病害的成功有限。 这很可能是由于环境条件的波动，导致有益细菌产生的抗真菌产品的量发生变化。 菌株PA 23和DF 41产生控制真菌生长的抗生素和酶，从而控制疾病。 我们的研究重点是了解负责疾病控制（生物控制）的基因是如何调节的。 我们将研究一种新的基因表达调节因子PtrA如何控制PA23和DF41中抗生素和酶的产生。 此外，我们将研究这些抗生素输出到细菌细胞外的方式。 DF41产生的抗生素的化学结构目前尚不清楚，因此我们将推断其结构。 在环境中，营养素是稀缺的，因此，我们将调查有限的食物供应对基因表达和疾病抑制所需的产品的影响。 这些研究将揭示PA23和DF41如何能够抑制真菌生长。 这将使我们能够以一致和可预测的方式使用这两种细菌作为农药替代品。