The vegetative mycelium of Agaricus bisporus supplies developing white button mushrooms with water and nutrients. However, it is not yet known which part of the mycelium contributes to the feeding of the mushrooms and how this depends on growth conditions. Here we used photon counting scintillation imaging to track translocation of the 14C-radiolabeled metabolically inert amino acid analogue α-aminoisobutyric acid (14C-AIB). Translocation to the periphery of the mycelium was observed in actively growing vegetative mycelium with a velocity of up to 6.6 mm h-1, which was 30-fold higher than the growth rate. Furthermore, 14C-AIB translocated to neighboring colonies after fusion by anastomosis depending on the relative growth rate in these colonies. When mushrooms started to develop, translocation of 14C-AIB was redirected to the fruiting bodies via mycelium and hyphal cords. More abundant mycelial cord formation and a 5-fold higher rate of translocation was observed for cultures growing directionally from inoculum located at one side of the substrate, when compared to non-directional growth (inoculum mixed throughout the substrate). The maximum translocation distance was also greater (≥50 and 22 cm, respectively). In conclusion, 14C-AIB translocation switches between vegetative growth and towards developing mushrooms, especially via cords and when source-sink relationships change.

中文翻译：

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生长诱导的易位有效地将氨基酸类似物引导至双孢蘑菇的发育区

双孢蘑菇的营养菌丝体为发育中的白蘑菇提供水分和营养。然而，目前尚不清楚菌丝体的哪一部分有助于蘑菇的摄食以及这如何取决于生长条件。在这里，我们使用光子计数闪烁成像来跟踪 14C 放射性标记的代谢惰性氨基酸类似物 α-氨基异丁酸 (14C-AIB) 的易位。在活跃生长的营养菌丝体中观察到菌丝体外围的易位，其速度高达 6.6 mm h-1，比生长速度高 30 倍。此外，14C-AIB 通过吻合术融合后易位到邻近的集落，这取决于这些集落的相对生长速度。当蘑菇开始发育时，14C-AIB 的易位通过菌丝体和菌丝带重定向到子实体。与非定向生长（接种物在整个基质中混合）相比，从位于基质一侧的接种物定向生长的培养物观察到更丰富的菌丝索形成和 5 倍高的易位率。最大易位距离也更大（分别≥50 和 22 cm）。总之，14C-AIB 易位在营养生长和蘑菇发育之间切换，尤其是通过绳索和源库关系发生变化时。与非定向生长（接种物在整个基质中混合）相比。最大易位距离也更大（分别≥50 和 22 cm）。总之，14C-AIB 易位在营养生长和蘑菇发育之间切换，尤其是通过绳索和源库关系发生变化时。与非定向生长（接种物在整个基质中混合）相比。最大易位距离也更大（分别≥50 和 22 cm）。总之，14C-AIB 易位在营养生长和蘑菇发育之间切换，尤其是通过绳索和源库关系发生变化时。