ИСТИНА

Many plants release airborne volatile compounds in response to wounding due to pathogenic assault. These compounds serve as plant defenses and are involved in plant signaling. The mechanisms by which these signals promote plant immunity remain elusive. We demonstrate that plant leaf wounding results in the synthesis of a cell wall enzyme, pectin methylesterase (PME), causing the plant to release methanol into the air. Gaseous methanol or vapors from wounded PME-transgenic plants induced resistance to the bacterial pathogen Ralstonia solanacearum in the leaves of non-wounded neighboring “receiver” plants. To investigate the mechanism underlying this phenomenon, we identified the methanol inducible genes (MIGs) in Nicotiana benthamiana, most of which fell into the category of defense genes. We selected and isolated the following genes: non-cell-autonomous pathway protein (NCAPP), β-1,3-glucanase (BG), and the previously unidentified MIG-21. We demonstrated that BG, MIG-21 and NCAPP could enhance cell-to-cell communication and Tobacco mosaic virus (TMV) RNA accumulation. Moreover, gaseous methanol or vapors from wounded plants increased TMV reproduction in “receivers”. Thus, methanol emitted by a wounded plant enhances antibacterial resistance as well as cell-to-cell communication that facilitate virus spreading in neighboring plants.