4 CONCLUDING REMARKS
Plants have adapted to growth in complex and competitive ecosystems
during their evolutionary history. They need to compete with
interspecific and conspecific plants for light, water, and nutrients,
and communicate with neighboring plants to anticipate upcoming
biotic/abiotic challenges (Ballaré & Austin, 2019, Effah, Holopainen &
McCormick, 2019, Hodge, Fitter & Robinson, 2013, Hortal et al. ,
2017). However, only some of the competition and communication
mechanisms rely on the plant genome. Plant microbiota have pivotal roles
in nutrient solubility and uptake, especially nitrogen, phosphorus, and
iron (Adesemoye, Torbert & Kloepper, 2008, Sharifi, Ahmadzadeh,
Sharifi-Tehrani & Talebi-Jahromi, 2010). Microbiota also improve water
use efficiency and osmotic stress response (Fan, Hu, Huang, Huang, Li &
Palta, 2015, Sharifi & Ryu, 2018c). The plant holobiome leverages the
collection of its member genes to optimize performance and survival.
Plants have spatiotemporal layers of defense consisting of rhizosphere
microbes, endophytes, pattern-triggered immunity, effector-triggered
immunity, and recruited natural enemies; each of these can efficiently
suppress specific groups of attackers (Carrión et al. , 2019,
Sharifi & Ryu, 2017). Because of these advantages conferred by
microbiota, plants donate 10–30% of their carbon and nitrogen to the
rhizosphere to organize their microbiota.
Information and signal transferring systems play important roles in
plant growth and survival. Plants decipher their complex habitat
situations by perceiving physical and chemical cues and signals, either
directly from neighboring plants or indirectly from their symbionts such
as mycorrhiza, endophytic fungi and dodder. Previous research has
characterized the signal types and signal mediators involved in plant
interactions with other members of the ecosystem and revealed that deaf
and mute mutants of plants have reduced ecological competence. However,
plants may lose some of their communication abilities during
domestication and plant breeding programs. Therefore, plant breeders and
genetic engineers should have a holistic view of plants as members of
the holobiome. Otherwise, small changes in key ecology-related genes may
substantially affect plant performance, a phenomenon called the
butterfly effect.
Agricultural practices also affect plant-plant communication. As we
mentioned above, no-tillage and minimum tillage systems preserve common
mycorrhizal networks and endophytic fungi as mediators of wired
plant-plant communication. Moreover, Information can transfer between
plants during intercropping or from crop to crop in the next season.
Thus, recent advances in our understanding of plant-plant communication
can help manage agricultural practices so that they utilize the
abilities of plants to exploit ecological interactions, and survive in
competitive environments.