Harnessing the Perception of Trichoderma Signal Molecules in Rhizosphere to Improve Soil Health and Plant Health

Abstract

In the fungal kingdom, Trichoderma is the most exploited biocontrol agent. It is known for its ability to colonize plant root, suppress many plant pathogens, and act as inducer of systemic resistance in plant and is also involved in growth promotional activities. The knowledge on rhizosphere signalling between plant root–Trichoderma interaction is highly essential to trigger the immune response and to improve plant health. There is a bidirectional perception of signal molecules for the successful establishment of its association. The interaction of Trichoderma starts with contact to the root surface, followed by attachment, penetration, and colonization. The signal molecules from root exudates and secretomes of Trichoderma are essential for successful accomplishment of a symbiotic relationship. Among the complex composition of root exudates, sucrose plays a vital role in the attraction of Trichoderma to the plant root system. The hydrophobin and swollenins and cysteine-rich proteins secreted by Trichoderma plays a role in each step towards successful plant root interaction. This review enlightens our knowledge on root–Trichoderma interaction and its ability to overcome plant’s defense mechanism to prove itself as a “true friend” to the plant system and for improvement of soil and plant health.