Małopolska Centre of Biotechnology, Jagiellonian University, Gronostajowa 7A, 30-387 Kraków, Poland.
W. Szafer Institute of Botany Polish Academy of Sciences, Lubicz 46, 31-512 Kraków, Poland.
Sci Total Environ. 2023 Apr 20;870:161887. doi: 10.1016/j.scitotenv.2023.161887. Epub 2023 Jan 30.
The endophytic Basidiomycete Sporobolomyces ruberrimus protects its host Arabidopsis arenosa against metal toxicity. Plants inoculated with the fungus yielded more biomass and exhibited significantly fewer stress symptoms in medium mimicking mine dump conditions (medium supplemented with excess of Fe, Zn and Cd). Aside from fine-tuning plant metal homeostasis, the fungus was capable of precipitating Fe in the medium, most likely limiting host exposure to metal toxicity. The precipitated residue was identified by Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), X-Ray Diffraction (XRD) and electron microscopy (SEM/TEM) with energy dispersive X-Ray analysis (EDX/SAED) techniques. The performed analyses revealed that the fungus transforms iron into amorphous (oxy)hydroxides and phosphates and immobilizes them in the form of a precipitate changing Fe behaviour in the MSR medium. Moreover, the complexation of free Fe ions by fungi could be obtained by biomolecules such as lipids, proteins, or biosynthesized redox-active molecules.
内生担子菌 Sporobolomyces ruberrimus 可保护其宿主拟南芥免受金属毒性的侵害。与未接种真菌的植物相比，接种真菌的植物在模拟矿山堆浸条件的培养基（补充过量铁、锌和镉的培养基）中生长得更好，表现出的胁迫症状也更少。除了微调植物的金属稳态外，该真菌还能够在培养基中沉淀铁，这很可能限制了宿主对金属毒性的暴露。沉淀残余物通过傅里叶变换红外光谱（FTIR）、X 射线光电子能谱（XPS）、X 射线衍射（XRD）和电子显微镜（SEM/TEM）结合能色散 X 射线分析（EDX/SAED）技术进行了鉴定。分析表明，真菌将铁转化为无定形（氧）氢氧化物和磷酸盐，并以沉淀的形式将其固定，从而改变 MSR 培养基中铁的行为。此外，真菌可以通过生物分子如脂质、蛋白质或生物合成的氧化还原活性分子来螯合游离的 Fe 离子。
