cross-kingdom-signaling
Cross-kingdom signaling refers to the molecular communication that occurs between organisms from different biological kingdoms, such as plants exchanging chemical signals with fungi, bacteria, or animals. In plant science, this field illuminates how plants perceive and respond to microbes in the rhizosphere, coordinate symbiotic relationships like mycorrhizal associations, and mount defenses against pathogens. Understanding these inter-kingdom dialogues is transforming our knowledge of plant immunity, nutrient acquisition, and ecosystem interactions.
open_in_new WikipediaPubMed · 2026-05-06
Ethylene, the gas plants use to ripen fruit and signal stress, turns out to be detected not just by plants but also by bacteria — and possibly fungi. Over the past decade, scientists discovered that some microbes carry receptors nearly identical to plant ethylene receptors, meaning this ancient signaling molecule coordinates life across multiple kingdoms.
Bacteria possess functional plant-like ethylene receptors confirmed across multiple studies over the past decade, with ethylene binding shown to significantly alter bacterial metabolism and physiology.
Some fungi may also carry functional plant-like ethylene receptors with binding domains structurally similar to those in plants, extending ethylene sensing beyond the plant and bacterial kingdoms.
Microbes may additionally possess entirely distinct, noncanonical ethylene receptors that are evolutionarily unrelated to plant receptors, suggesting ethylene sensing may have evolved independently multiple times across life.