Kyohei Fukuda, Masayoshi Uefune, Hidehiro Fukaki, Yasuo Yamauchi, Ikuko Hara-Nishimura, Rika Ozawa, Kenji Matsui, Koichi Sugimoto, Kazunori Okada, Ryozo Imai, Kenshi Takahashi, Shinichi Enami, René Wurst, and Junji Takabayashi
One of the characteristic aspects of odour sensing in humans is the activation of olfactory receptors in a slightly different manner in response to different enantiomers. Here, we focused on whether plants showed enantiomer-specific response similar to that in humans. We exposed Arabidopsis seedlings to methanol (control) and (+)- or (−)-borneol, and found that only (+)-borneol reduced the root length. Furthermore, the root-tip width was more increased upon (+)-borneol exposure than upon (−)-borneol exposure. In addition, root-hair formation was observed near the root tip in response to (+)-borneol. Auxin signalling was strongly reduced in the root tip following exposure to (+)-borneol, but was detected following exposure to (−)-borneol and methanol. Similarly, in the root tip, the activity of cyclin B1:1 was detected on exposure to (−)-borneol and methanol, but not on exposure to (+)-borneol, indicating that (+)-borneol inhibits the meristematic activity in the root. These results partially explain the (+)-borneol-specific reduction in the root length of Arabidopsis. Our results indicate the presence of a sensing system specific for (+)-borneol in Arabidopsis.