Department of Life Sciences and Systems Biology (UNITO-DBIOS), University of Turin, Turin, Italy.
Methods Mol Biol. 2021;2309:75-89. doi: 10.1007/978-1-0716-1429-7_7.
Strigolactones (SLs) are components of root exudates as a consequence of active release from the roots into the soil. Notably, they have been described as stimulants of seed germination in parasitic plants and of the presymbiotic growth in arbuscular mycorrhizal (AM) fungi, which are a crucial component of the plant root beneficial microbiota. SLs have therefore the potential to influence other microbes that proliferate in the soil around the roots and may interact with plants. A direct effect of SL analogs on the in vitro growth of a number of saprotrophic or plant pathogenic fungi was indeed reported.Here we describe a standardized method to evaluate the effect of SLs or their synthetic analogs on AM and filamentous fungi. For AM fungi, we propose a spore germination assay since it is more straightforward than the hyphal branching assay and it does not require deep expertise and skills. For filamentous fungi that can grow in axenic cultures, we describe the assay based on SLs embedded in the solid medium or dissolved in liquid cultures where the fungus is inoculated to evaluate the effect on growth, hyphal branching or conidia germination. These assays are of help to test the activity of natural SLs as well as of newly designed SL analogs for basic and applied research.
独脚金内酯（SLs）是根系分泌物的组成部分，是根系主动释放到土壤中的结果。值得注意的是，它们被描述为寄生植物种子萌发的刺激物，以及丛枝菌根（AM）真菌的共生前生长的刺激物，而 AM 真菌是植物根系有益微生物群落的关键组成部分。因此，SLs 有可能影响在根系周围土壤中增殖的其他微生物，并可能与植物相互作用。事实上，已经有报道称 SL 类似物对一些腐生或植物病原真菌的离体生长有直接影响。在这里，我们描述了一种标准化的方法来评估 SL 或其合成类似物对 AM 和丝状真菌的影响。对于 AM 真菌，我们提出了一种孢子萌发测定法，因为它比菌丝分枝测定法更简单，并且不需要深入的专业知识和技能。对于可以在无菌培养中生长的丝状真菌，我们描述了基于 SL 嵌入固体培养基或溶解在液体培养物中的测定法，在液体培养物中接种真菌以评估其对生长、菌丝分枝或分生孢子萌发的影响。这些测定法有助于测试天然 SLs 以及新设计的 SL 类似物的活性，可用于基础和应用研究。
