Department of Biochemistry and Molecular Biology, Federal University of Ceará, Fortaleza, Ceará, Brazil.
Department of Biochemistry and Molecular Biology, Federal University of Ceará, Fortaleza, Ceará, Brazil; Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, IA, USA.
Plant Sci. 2022 Nov;324:111427. doi: 10.1016/j.plantsci.2022.111427. Epub 2022 Aug 23.
Although floral nectar is a rich source of nutrients, it is rarely infected by microorganisms. Defense molecules such as proteins have been identified in this fluid, but defense peptides have been largely overlooked. Thus, the aim of this study was to perform an extensive peptidomic analysis of the ornamental tobacco floral nectar to seek peptides involved in nectar defense. Using LC-MS/MS, 793 peptides were sequenced and characterized. After extensive bioinformatics analysis, six peptides were selected for further characterization, synthesis, and evaluation of their antimicrobial properties against phytopathogenic fungi and bacteria. All six peptides had antimicrobial activity to some extent. However, the activity varied by peptide concentration and microorganism tested. An analysis of the action mechanism revealed damage in the cell membrane induced by peptides. The results show that floral nectar is rich in peptides and that, together with proteins and hydrogen peroxide, they contribute to plant defense against microorganisms during pollination.
虽然花卉花蜜是一种营养丰富的物质，但它很少受到微生物的感染。在这种液体中已经鉴定出蛋白质等防御分子，但防御肽在很大程度上被忽视了。因此，本研究的目的是对观赏烟草花卉花蜜进行广泛的肽组学分析，以寻找参与花蜜防御的肽。使用 LC-MS/MS，对 793 种肽进行了测序和表征。经过广泛的生物信息学分析，选择了六种肽进行进一步的表征、合成和评估它们对植物病原菌真菌和细菌的抗菌特性。这六种肽都具有一定的抗菌活性。然而，活性因肽浓度和测试的微生物而异。对作用机制的分析表明，肽诱导了细胞膜的损伤。研究结果表明，花蜜富含肽，与蛋白质和过氧化氢一起，在授粉过程中有助于植物抵御微生物的侵害。
