Development of the infection strategy of the hemibiotrophic plant pathogen, Colletotrichum orbiculare, and plant immunity. (July 2016)

• Record Type: Journal Article
• Authors: Kubo, Yasuyuki; Harata, Ken; Kodama, Sayo; Fukada, Fumi
• Is Part Of: Physiological and molecular plant pathology. Volume 95(2016:Jul.)
• Page Start: 32
• Page End: 36
• Publication Date: 2016-07
• Subjects: Colletotrichum -- Hemibiotrophy -- Cell cycle -- Signal transduction -- Appressoria; Plant diseases -- Periodicals; Diseased plants -- Physiology -- Periodicals; Phytopathogenic microorganisms -- Host plants -- Periodicals; 632
• DOI: 10.1016/j.pmpp.2016.02.008
• Languages: English
• ISSNs: 0885-5765

Abstract

Abstract: The hemibiotrophic fungus Colletotrichum orbiculare forms appressoria as infection structures and primarily establishes biotrophic infection in cucumber epidermal cells. Subsequently, it develops necrotrophic infection. In the pre-invasion stage, morphogenesis of appressoria of C. orbiculare is triggered by signals from the plant surface. We found that C. orbiculare PAG1 (Perish-in-the-Absence-of- GYP1 ), a component of MOR [morphogenesis-related NDR (nuclear Dbf2-related) kinase network] plays an essential role as a key component of the plant-specific signaling pathway and that hydrolysis of cutin by a spore surface esterase creates a cutin monomer that constitutes a key plant-derived signal. Development of the infection structure of C. orbiculare is strictly regulated by the cell cycle and we found that proper regulation of G1/S progression via two-component GAP genes, consisting of BUB2 (Budding-Uninhibited-by-Benomyl-2) and BFA1 (Byr-Four-Alike-1) is essential for the establishment of successful infection. In the post-invasion stage, the establishment of the biotrophic phase of hemibiotrophic fungi is crucial for successful infection. We found that C. orbiculare WHI2 (WHIsky-2), an Saccharomyces cerevisiae stress regulator homolog, is involved in the phase transition from biotrophy to necrotrophy through TOR (Target of Rapamycin) signaling, and is thus essential for full pathogenesis. Highlights: The Colletotrichum orbiculare Pag1gene is a key component of the plant-specific signaling pathway. A cutin monomer, n -octadecanal, constitutes a key plant-derived signal. Proper cell cycle progression is essential for successful infection in Colletotrichum orbiculare . The Colletotrichum orbiculare Whi2 gene is involved in the establishment of hemibiotrophic infection.