小柯机器人

美国索尔克生物研究所Wolfgang Busch团队近日取得一项新成果。经过不懈努力，他们发现IMA1调控限制了根系通过MAMP感知获取铁。2024年1月10日出版的《自然》发表了这项成果。

研究人员在拟南芥中发现了一种微生物相关分子模式（如鞭毛蛋白），其通过局部降解系统缺铁信号肽Iron Man 1（IMA1）来抑制根部铁吸收。当细菌进入根部组织时也会引起这种反应，但当细菌停留在根部外表面时则不会。IMA1本身具有调节根部和芽部免疫的功能，影响根部定植水平和对细菌性叶面病原体的抵抗力。该研究结果揭示了营养免疫的适应性分子机制，它影响铁的生物利用率和吸收以及免疫反应。

据悉，铁在宿主与微生物相互作用中发挥功能。宿主在感染期间限制铁的可用性是一种重要的防御策略，被称为营养免疫。然而，这对于肠道上皮细胞或植物根表皮等具有吸收能力的外向型组织来说是一个难题，因为这些组织所处的环境有利于铁的生物利用。例如，植物根系主要从土壤中获取铁，当缺铁时，根系会通过根圈酸化和分泌铁螯合剂等机制提高铁的可用性。然而，铁生物利用率的提高也有利于威胁植物健康细菌的生长。

附：英文原文

Title: Spatial IMA1 regulation restricts root iron acquisition on MAMP perception

Author: Cao, Min, Platre, Matthieu Pierre, Tsai, Huei-Hsuan, Zhang, Ling, Nobori, Tatsuya, Armengot, Laia, Chen, Yintong, He, Wenrong, Brent, Lukas, Coll, Nuria S., Ecker, Joseph R., Geldner, Niko, Busch, Wolfgang

Issue&Volume: 2024-01-10

Abstract: Iron is critical during host–microorganism interactions1,2,3,4. Restriction of available iron by the host during infection is an important defence strategy, described as nutritional immunity5. However, this poses a conundrum for externally facing, absorptive tissues such as the gut epithelium or the plant root epidermis that generate environments that favour iron bioavailability. For example, plant roots acquire iron mostly from the soil and, when iron deficient, increase iron availability through mechanisms that include rhizosphere acidification and secretion of iron chelators6,7,8,9. Yet, the elevated iron bioavailability would also be beneficial for the growth of bacteria that threaten plant health. Here we report that microorganism-associated molecular patterns such as flagellin lead to suppression of root iron acquisition through a localized degradation of the systemic iron-deficiency signalling peptide Iron Man 1 (IMA1) in Arabidopsis thaliana. This response is also elicited when bacteria enter root tissues, but not when they dwell on the outer root surface. IMA1 itself has a role in modulating immunity in root and shoot, affecting the levels of root colonization and the resistance to a bacterial foliar pathogen. Our findings reveal an adaptive molecular mechanism of nutritional immunity that affects iron bioavailability and uptake, as well as immune responses.

DOI: 10.1038/s41586-023-06891-y

Source: https://www.nature.com/articles/s41586-023-06891-y

Nature：《自然》，创刊于1869年。隶属于施普林格·自然出版集团，最新IF：69.504
官方网址：http://www.nature.com/
投稿链接：http://www.nature.com/authors/submit_manuscript.html