www.landesbioscience.com Plant Signaling & Behavior e24619-1 Plant Signaling & Behavior 8:7, e24619; July 2013; © 2013 Landes Bioscience

org/10.4161/psb.24619 The group of root-colonizing bacteria that is called as plant growth-promoting rhizobacteria (PGPR) confers beneficial effects to plants, including induction of systemic resistance (ISR) against phytopathogens and herbivores.1-3 Many bacterial deter-minants for such mechanism from PGPR have been discovered.4,5 Previous research suggested that components of the bacterial cell membrane and some secondary metabolites contributed to ISR.1-3,6 In 2003, bacterial volatiles produced from Bacillus subtilis strain GB03 were found to act as a determinant for ISR.7-9 Out of> 30 volatile organic compounds (VOCs) from strain GB03, a C4 hydrocarbon 2,3-butanediol played a critical role in ISR against Pectobacterium carotovorum subsp carotovorum. A later study revealed that ethylene signaling was essential for elicita-tion of ISR using PDF1.2 and Jin14 indicator genes for ethylene