MIP diversity from Trichoderma: Structural considerations and transcriptional modulation during mycoparasitic association with Fusarium solani olive trees

Maroua Ben Amira (1) , Robin Mom (1) , David Lopez (1) , Hatem Chaar (2) , Ali Khouaja (2) , Valérie Pujade-Renaud (1, 3) , Boris Fumanal (1) , Aurelie Gousset (1) , Gisèle Bronner (4) , Philippe Label (1) , Jean-Louis J.-L. Julien (1) , Mohamed Ali Triki (5) , Daniel Auguin (4) , Jean-Stéphane Venisse (1)

1 PIAF - Laboratoire de Physique et Physiologie Intégratives de l’Arbre en environnement Fluctuant
2 Institut National Agronomique de Tunisie
3 UMR AGAP - Amélioration génétique et adaptation des plantes méditerranéennes et tropicales
4 LBLGC - Laboratoire de Biologie des Ligneux et des Grandes Cultures
5 Institut de l'Olivier

Major intrinsic proteins (MIP) are characterized by a transmembrane pore-type architecture that facilitates transport across biomembranes of water and a variety of low molecular weight solutes. They are found in all parts of life, with remarkable protein diversity. Very little is known about MIP from fungi. And yet, it can legitimately be stated that MIP are pivotal molecular components in the privileged relationships fungi enjoy with plants or soil fauna in various environments. To date, MIP have never been studied in a mycoparasitism situation. In this study, the diversity, expression and functional prediction of MIP from the genus Trichoderma were investigated. Trichoderma spp. genomes have at least seven aquaporin genes. Based on a phylogenetic analysis of the translated sequences, members were assigned to the AQP, AQGP and XIP subfamilies. In in vitro and in planta assays with T. harzianum strain Ths97, expression analyses showed that four genes were constitutively expressed. In a mycoparasitic context with Fusarium solani, the causative agent of fusarium dieback on olive tree roots, these genes were up-regulated. This response is of particular interest in analyzing the MIP promoter cis-regulatory motifs, most of which are involved in various carbon and nitrogen metabolisms. Structural analyses provide new insights into the possible role of structural checkpoints by which these members transport water, H2O2, glycerol and, more generally, linear polyols across the membranes. Taken together, these results provide the first evidence that MIP may play a key role in Trichoderma mycoparasitism lifestyle.

Mots clés: phylogenetic analysis; expression analysis; protein-structure; ascomycete fungi; aquaporins; genes; plant; water; harzianum; Science & Technology - Other Topics; aquaporin

Mots clés: analyse phylogénétique; aquaporine; plante; trichoderma harzianum; gène; eau; transport

Domaines: Biologie végétale

Maroua Ben Amira, Robin Mom, David Lopez, Hatem Chaar, Ali Khouaja, et al.. MIP diversity from Trichoderma: Structural considerations and transcriptional modulation during mycoparasitic association with Fusarium solani olive trees. PLoS ONE, 2018, 13 (3), pp.23. ⟨10.1371/journal.pone.0193760⟩. ⟨hal-01779754⟩