The seven-transmembrane receptor Gpr1 governs processes relevant for the antagonistic interaction of Trichoderma atroviride with its host

Abstract

Mycoparasitic Trichoderma species are applied as biocontrol agents in agriculture to guard plants against fungal diseases. During mycoparasitism, Trichoderma directly interacts with phytopathogenic fungi, preceded by a specific recognition of the host and resulting in its disarming and killing. In various fungal pathogens, including mycoparasites, signalling via heterotrimeric G proteins plays a major role in regulating pathogenicity-related functions. However, the corresponding receptors involved in the recognition of host-derived signals are largely unknown. Functional characterization of Trichoderma atroviride Gpr1 revealed a prominent role of this seven-transmembrane protein of the cAMP-receptor-like family of fungal G-protein-coupled receptors in the antagonistic interaction with the host fungus and governing of mycoparasitism-related processes. Silencing of gpr1 led to an avirulent phenotype accompanied by an inability to attach to host hyphae. Furthermore, gpr1-silenced transformants were unable to respond to the presence of living host fungi with the expression of chitinase- and protease-encoding genes. Addition of exogenous cAMP was able to restore host attachment in gpr1-silenced transformants but could not restore mycoparasitic overgrowth. A search for downstream targets of the signalling pathway(s) involving Gpr1 resulted in the isolation of genes encoding e.g. a member of the cyclin-like superfamily and a small secreted cysteine-rich protein. Although silencing of gpr1 caused defects similar to those of mutants lacking the Tga3 Gα protein, no direct interaction between Gpr1 and Tga3 was observed in a split-ubiquitin two-hybrid assay.

Comparative analysis of the repertoire of G protein-coupled receptors of three species of the fungal genus Trichoderma

“…Besides these defects in mycoparasitism-relevant activities, Gpr1 further affects vegetative growth and conidiation of T . atroviride [50]. As Gpr1 did not interact with any of the three T .…”

“…As Gpr1 did not interact with any of the three T . atroviride Gα proteins (Tga1, Tga2, or Tga3) in a split-ubiquitin yeast-two-hybrid assay [50], signal transduction in a G protein-independent manner cannot be ruled out at the moment.…”

The Genomes of Three Uneven Siblings: Footprints of the Lifestyles of Three Trichoderma Species

“…T. atroviride gpr1 (TA_160995) encodes a GPCR belonging to the class of cAMP receptor-like proteins (class V) which was not only shown to be essential for vegetative growth and conidiation (54) but also to govern mycoparasitism-related processes, such as coiling and expression of chitinase-encoding genes upon induction by the living host (625).…”

Pengujian Trichoderma Sp. Sebagai Pengendali Hawar Daun Bibit Kakao Yang Disebabkan Oleh Phythopthora Palmivora

“…Mengingat aplikasi fungisida untuk mengendalikan patogen ini selain berdampak negatif terhadap lingkungan juga menimbulkan resistensi patogen terhadap fungisida, maka pemanfaatan agensia hayati, terutama Trichoderma, makin banyak dikembangkan. Trichoderma memproduksi sejumlah metabolit sekunder gliotoksin (Mukherjee et al, 2013), enzim hidrolitik serta mampu memparasit inang yang terinduksi oleh respons terhadap molekul (ekstraselular) yang dikeluarkan inang (Omann et al, 2012). Dengan keunggulan berbagai karakter biologi dan ketersediaan di area pertanaman, maka dapat diandalkan sebagai agensia hayati pengendali patogen yang efektif, efisien, juga ramah lingkungan.…”