Global Gene Expression Profiling During Medicago truncatula–Phymatotrichopsis omnivora Interaction Reveals a Role for Jasmonic Acid, Ethylene, and the Flavonoid Pathway in Disease Development

Autor: Srinivasa Rao Uppalapati, Stephen M. Marek, Hee-Kyung Lee, Jin Nakashima, Yuhong Tang, Mary K. Sledge, Richard A. Dixon, Kirankumar S. Mysore
Jazyk: angličtina
Rok vydání: 2009
Předmět:
Zdroj: Molecular Plant-Microbe Interactions, Vol 22, Iss 1, Pp 7-17 (2009)
Druh dokumentu: article
ISSN: 1943-7706
0894-0282
DOI: 10.1094/MPMI-22-1-0007
Popis: Phymatotrichopsis omnivora (Duggar) Hennebert causes a destructive root rot in cotton, alfalfa (Medicago sativa), and many other dicot species. No consistently effective control measures or resistant host germplasm for Phymatotrichum root rot (PRR) are known. The relative genetic intractability of cotton and alfalfa precludes their use as model pathosystem hosts for P. omnivora. Therefore, we used the model legume M. truncatula and its available genetic and genomic resources to investigate PRR. Confocal imaging of P. omnivora interactions with M. truncatula roots revealed that the mycelia do not form any specialized structures for penetration and mainly colonize cortical cells and, eventually, form a mycelial mantle covering the root's surfaces. Expression profiling of M. truncatula roots infected by P. omnivora identified several upregulated genes, including the pathogenesis-related class I and class IV chitinases and genes involved in reactive oxygen species generation and phytohormone (jasmonic acid and ethylene) signaling. Genes involved in flavonoid biosynthesis were induced (2.5- to 10-fold over mock-inoculated controls) at 3 days postinoculation (dpi) in response to fungal penetration. However, the expression levels of flavonoid biosynthesis genes returned to the basal levels with the progress of the disease at 5 dpi. These transcriptome results, confirmed by real-time quantitative polymerase chain reaction analyses, showed that P. omnivora apparently evades induced host defenses and may downregulate phytochemical defenses at later stages of infection to favor pathogenesis.
Databáze: Directory of Open Access Journals
Externí odkaz: