Auxins influence the growth of stems toward light (phototropism) and against the force of gravity (geotropism).

它可影响茎的向光性和背地性生长。

The geotropism growth was a response of hypha to gravity and the geotropic sensitive was at the hyphal apex.

丛枝菌根真菌菌丝延伸生长部位是菌丝尖端，其生长的向地性是对地心引力的感应，感应的敏感部位也在生长菌丝的尖端。