3 WIRELESS COMMUNICATION: SIGNAL INPUT-TRANSFER-OUTPUT MODEL
Plants normally release volatile and non-volatile chemicals that can be
exploited by other plants as a source of signal molecules
(infochemicals). Here, we discuss how these plant infochemicals can be
elicited by microbes, insects, and environmental stimuli. These
infochemicals diffuse via air and soil pores to reach neighbor plants.
Receiver plants can amplify the released infochemical signals to expand
the effective infochemical signaling zone. Infochemicals perceived by
the receiver plants can act as kin recognition signals, growth
inhibitors (allelopathy), growth stimulators, and defense signals
(Karban, Shiojiri, Ishizaki, Wetzel & Evans, 2013, Kong, Zhang, Li,
Xia, Yang, Meiners & Wang, 2018a, Kong, Zhang, Li, Xia, Yang, Meiners
& Wang, 2018b, Sharifi et al. , 2018, Sharifi & Ryu, 2018b).
Infochemicals can directly change the transcriptome and physiology of
receiver plants to prime for imminent threats, or they may indirectly
change the plant microbiome in neighboring plants through a facilitative
or competitive mechanism (Carvalhais, Dennis, Badri, Kidd, Vivanco &
Schenk, 2015, Li, Zhao & Kong, 2020a, Mannaa, Han, Jeon, Kim, Kim,
Park, Kim & Seo, 2020, Vannier, Bittebiere, Mony & Vandenkoornhuyse,
2020).