Host Tissue Environment Directs Activities of an Epichloë Endophyte, While It Induces Systemic Hormone and Defense Responses in Its Native Perennial Ryegrass Host

Authors

Jan Schmid, Massey University, New Zealand
Robert Day, University of Otago, New Zealand
Ningxin Zhang, Massey University, New Zealand
Pierre-Yves Dupont, Massey University, New Zealand
Murray P. Cox, Massey University, New Zealand
Christopher L. Schardl, University of KentuckyFollow
Niki Minards, Manawatu Microscopy and Imaging Centre, New Zealand
Neil Moore, University of KentuckyFollow
Daniel R. Harris, University of KentuckyFollow
Yanfei Zhou, Massey University, New Zealand

Abstract

Increased resilience of pasture grasses mediated by fungal Epichloë endophytes is crucial to pastoral industries. The underlying mechanisms are only partially understood and likely involve very different activities of the endophyte in different plant tissues and responses of the plant to these. We analyzed the transcriptomes of Epichloë festucae and its host, Lolium perenne, in host tissues of different function and developmental stages. The endophyte contributed approximately 10× more to the transcriptomes than to the biomass of infected tissues. Proliferating mycelium in growing host tissues highly expressed genes involved in hyphal growth. Nonproliferating mycelium in mature plant tissues, transcriptionally equally active, highly expressed genes involved in synthesizing antiherbivore compounds. Transcripts from the latter accounted for 4% of fungal transcripts. Endophyte infection systemically but moderately increased transcription of L. perenne genes with roles in hormone biosynthesis and perception as well as stress and pathogen resistance while reducing expression of genes involved in photosynthesis. There was a good correlation between transcriptome-based observations and physiological observations. Our data indicate that the fitness-enhancing effects of the endophyte are based both on its biosynthetic activities, predominantly in mature host tissues, and also on systemic alteration of the host’s hormonal responses and induction of stress response genes.

Document Type

Article

Publication Date

2-2017

Notes/Citation Information

Published in Molecular Plant-Microbe Interactions, v. 30, no. 2, p. 138-149.

© 2017 The Author(s)

This is an open access article distributed under the CC BY-NC-ND 4.0 International license.

Digital Object Identifier (DOI)

https://doi.org/10.1094/MPMI-10-16-0215-R

Funding Information

The cost of sequencing by New Zealand Genomics Ltd. was subsidized by the New Zealand Ministry for Business Innovation and Employment. AgResearch Grasslands, the Bioprotection Centre, and the Marsden Fund provided funding towards this work.

Related Content

Sequence data are available in the GenBank database under accession numbers SRP062084 and GEZW01000000.

Repository Citation

Schmid, Jan; Day, Robert; Zhang, Ningxin; Dupont, Pierre-Yves; Cox, Murray P.; Schardl, Christopher L.; Minards, Niki; Moore, Neil; Harris, Daniel R.; and Zhou, Yanfei, "Host Tissue Environment Directs Activities of an Epichloë Endophyte, While It Induces Systemic Hormone and Defense Responses in Its Native Perennial Ryegrass Host" (2017). Plant Pathology Faculty Publications. 88.
https://uknowledge.uky.edu/plantpath_facpub/88