Pisolithus tinctorius is an ectomycorrhizal fungus that has been used worldwide as an inoculant to promote the growth and health of plant roots of forest importance. P. tinctorius has capacity to form symbiosis which mycorrhizal plants through the production of phytohormones, indole-3-acetic acid (IAA) the main auxin produced by these ectomycorrhizal fungi modulating root system architecture by inducing lateral root formation and root hair elongation in host plants of tree forest. However, the inoculant or compounds produced by P. tinctorius have not been evaluated in non-mycorrhizal plants. In the present study, we evaluated the effects of crude extracts of the P. tinctorius (CEPt) culture supernatant using Arabidopsis thaliana as plant model system to elucidate the molecular mechanisms of plant growth in non-host plant. Our results suggest that the crude extract of the supernatant produced by P. tinctorius has the ability to induce plant growth and root system architecture in Arabidopsis seedlings through the production of compounds with auxin-like activity, inducing the expression of DR5::uidA and BA3::uidA Arabidopsis line reporter of auxin responses and required an intact auxin signaling pathway, to modulate the plant growth in Arabidopsis seedlings.

Pisolithus tinctorius是一种外生菌根真菌，已在世界范围内用作接种剂，以促进对森林具有重要意义的植物根系的生长和健康。P. tinctorius有能力通过产生植物激素、吲哚-3-乙酸 (IAA) 来形成共生植物，这些外生菌根真菌产生的主要生长素通过诱导宿主植物的侧根形成和根毛伸长来调节根系结构的森林。然而，尚未在非菌根植物中评估P. tinctorius产生的接种剂或化合物。在本研究中，我们使用拟南芥 (Arabidopsis thaliana )评估了P. tinctorius (CEPt) 培养上清液的粗提取物的影响作为植物模型系统阐明植物在非寄主植物中生长的分子机制。我们的结果表明，P. tinctorius产生的上清液的粗提取物能够通过产生具有生长素样活性的化合物来诱导拟南芥幼苗的植物生长和根系结构，诱导DR5::uidA和BA3的表达::uidA拟南芥植物生长素反应的报告基因，需要完整的生长素信号通路，以调节拟南芥幼苗的植物生长。