Characterization of the High Affinity Salicylic Acid-Binding Protein 2 in Plant Disease Resistance

高亲和力水杨酸结合蛋白 2 在植物抗病性中的表征

• 批准号: 0525360
• 负责人: Daniel Klessig
• 金额: $ 64.36万
• 依托单位: Boyce Thompson Institute Plant Research
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-08-01 至 2009-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0525360&HistoricalAwards=false
• 关键词: Characterization; Affinity; Salicylic; Acid; Binding

Intellectual Merit: Broad-spectrum resistance to a wide array of pathogens, know as systemic acquired resistance (SAR), can be activated by infection with a pathogen or treatment with SAR-inducing natural chemicals such as salicylic acid (SA) and its synthetic functional analogues, INA or BTH. Salicylic acid (SA) is an important endogenous signal required for the activation of various local and systemic defense responses associated with plant innate immunity. To investigate how the SA signal is transduced, a tobacco SA-binding protein (SABP)2 that binds SA with high affinity has been identified. SABP2 shows strong esterase activity for methyl SA (MeSA), its preferred substrate. SA is a potent inhibitor of this catalysis. These observations are consistent with crystal structure analyses showing that MeSA readily fits into SABP2's active site and that SA also binds this site. Since silencing of SABP2 suppresses disease resistance, particularly SAR, SABP2 likely functions to convert biologically inactive MeSA into active SA as part of the signal transduction pathways that activate SAR and perhaps also local defense responses. The long-term objectives of this proposal are to decipher SABP2's role(s) in disease resistance and its mechanism(s) of action, thereby testing the above hypothesis. To achieve these objectives, the effect of altered SABP2 expression on disease resistance is being determined and whether or not MeSA is SABP2's natural substrate is being assessed. Using a novel complementation approach together with mutational analysis the importance of SABP2's esterase and SA-binding activities will be addressed. In addition, whether SABP2 is involved in producing/transmitting the mobile SAR signal or responding to this signal will be assessed.Broader Impacts: Plant disease causes an estimated loss worldwide of $100B annually. A variety of strategies are being developed to protect plants against disease. One approach is to induce the plant's own natural defenses. This strategy is attractive since it can provide protection against a broad spectrum of pathogens. The development of strategies that control disease by manipulating endogenous plant defense responses will be very important for sustaining agricultural production and improving our environment and health. The proposed research will provide a stimulating training environment for graduate and postdoctoral students, where they are exposed to a large repertoire of biochemical, molecular, genetic, pharmacological, and physiological approaches to address a complex biological question. In addition, this project will continue to provide undergraduates with opportunities to experience first-hand the excitement of discovery under the close mentorship of a postdoctoral fellow, research associate or graduate student during the academic year or in the BTI/Cornell Summer Internship Program. It also enables these graduate and postgraduate students to develop their teaching and mentoring skills.

智力优点：对多种病原体的广谱耐药性，称为系统获得性耐药性 (SAR)，可以通过病原体感染或用诱导 SAR 的天然化学物质（例如水杨酸 (SA) 及其合成功能类似物 INA 或 BTH）治疗来激活。水杨酸（SA）是激活与植物先天免疫相关的各种局部和全身防御反应所需的重要内源信号。为了研究 SA 信号如何转导，我们鉴定了一种以高亲和力结合 SA 的烟草 SA 结合蛋白 (SABP)2。 SABP2对其首选底物甲基SA (MeSA)表现出强酯酶活性。 SA 是该催化作用的有效抑制剂。这些观察结果与晶体结构分析一致，表明 MeSA 很容易融入 SABP2 的活性位点，并且 SA 也结合该位点。由于 SABP2 的沉默会抑制疾病抵抗力，特别是 SAR，因此 SABP2 可能具有将生物学上无活性的 MeSA 转化为活性 SA 的功能，作为激活 SAR 以及可能还激活局部防御反应的信号转导途径的一部分。该提案的长期目标是破译SABP2在抗病性中的作用及其作用机制，从而检验上述假设。为了实现这些目标，正在确定改变的 SABP2 表达对抗病性的影响，并评估 MeSA 是否是 SABP2 的天然底物。通过使用新的互补方法和突变分析，SABP2 酯酶和 SA 结合活性的重要性将得到解决。此外，还将评估 SABP2 是否参与产生/传输移动 SAR 信号或响应该信号。 更广泛的影响：植物病害每年在全球造成估计损失 100B 美元。人们正在开发多种策略来保护植物免受疾病侵害。一种方法是诱导植物自身的自然防御。这种策略很有吸引力，因为它可以提供针对多种病原体的保护。通过操纵内源植物防御反应来控制疾病的策略的制定对于维持农业生产和改善我们的环境和健康非常重要。拟议的研究将为研究生和博士后提供一个刺激的培训环境，让他们接触大量的生化、分子、遗传、药理学和生理学方法来解决复杂的生物学问题。此外，该项目将继续为本科生提供在学年或 BTI/康奈尔大学暑期实习计划中在博士后、研究员或研究生的密切指导下亲身体验发现的兴奋的机会。它还使这些研究生和研究生能够发展他们的教学和指导技能。