title: Cochliobolus lunatus colonizes potato by adopting different invasion strategies on cultivars: New insights on temperature dependent-virulence.
abstract: Extreme temperature fluctuations affect the interaction dynamics of Cochliobolus lunatus through temperature-dependent virulence, virulence differentiation and induced-virulence which poses a major threat to global food security. The relationship between higher temperature and pathogenicity of C. lunatus on reported hosts are poorly understood. In this study, temperature stress was applied on C. lunatus to investigate the correlation among the different types of conidia. Additionally, a comparative dissection of the invasion process, infection structures and conidial germination pattern on four different Solanum tuberosum L. (potato) cultivars were performed. Based on microscopic examination, it was found that C. lunatus adopts different hyphae morphology and septation pattern at different temperature regimes and produce different types of conidia. The study showed that four-celled conidia are overproduced at elevated temperature (>30 °C) than one, two, three and five-celled conidia. Our finding revealed that C. lunatus conidia exhibit bipolar germination (>14.67%, P<0.05), unipolar germination (>35.33%, P<0.05), penetrate subcutaneously via epidermal anticlinal cell wall (>0.33%, P < 0.05) and differentially form appressoria-like structures during colonization of four different potato cultivars. Importantly, it is shown that unipolar germination and bipolar germination in C. lunatus are independently occurring phenomenon irrespective of the host. It is confirmed that C. lunatus adopt different but highly successful strategies on four different potato cultivars to incite brown-to-black leaf spot disease. Altogether, our data showed that increase in temperature enhances C. lunatus virulence on different potato cultivars irrespective of their inherent thermotolerant traits.
authors.affiliation: Institute of Bioresources and Sustainable Development (IBSD), Takyelpat, Imphal 795001, Manipur, India; Department of Biotechnology, University of Burdwan, Golapbag More 713104, West Bengal, India; School of Basic and Biomedical Science, University of Health and Allied Sciences, PMB 31, Ho, Volta Region, Ghana. Electronic address: bengyellalouis@gmail.com.
authors.forename: Bengyella
authors.initials: B
authors.lastname: Louis
authors.affiliation: Institute of Bioresources and Sustainable Development (IBSD), Takyelpat, Imphal 795001, Manipur, India; School of Basic and Biomedical Science, University of Health and Allied Sciences, PMB 31, Ho, Volta Region, Ghana.
authors.forename: Sayanika D
authors.initials: SD
authors.lastname: Waikhom
authors.affiliation: Institute of Bioresources and Sustainable Development (IBSD), Takyelpat, Imphal 795001, Manipur, India.
authors.forename: Robinson C
authors.initials: RC
authors.lastname: Jose
authors.affiliation: Institute of Bioresources and Sustainable Development (IBSD), Takyelpat, Imphal 795001, Manipur, India.
authors.forename: Sailendra
authors.initials: S
authors.lastname: Goyari
authors.affiliation: Institute of Bioresources and Sustainable Development (IBSD), Takyelpat, Imphal 795001, Manipur, India; The Institute of Advanced Study in Science and Technology (IASST), Boragaon, Assam, India.
authors.forename: Narayan C
authors.initials: NC
authors.lastname: Talukdar
authors.affiliation: Department of Biotechnology, Haldia Institute of Technology, Haldia 721657, West Bengal, India. Electronic address: prpranabroy94@gmail.com.
authors.forename: Pranab
authors.initials: P
authors.lastname: Roy
mesh_terms: D001203:Ascomycota / Q000254:growth & development* / Q000528:radiation effects*; D025301:Hyphae / Q000254:growth & development / Q000528:radiation effects; D008853:Microscopy; D010935:Plant Diseases / Q000382:microbiology*; D011198:Solanum tuberosum / Q000382:microbiology*; D013172:Spores, Fungal / Q000254:growth & development / Q000528:radiation effects; D013696:Temperature; D014774:Virulence
keywords: Bipolar germination; Conidia; Scanning electron microscopy; Solanum tuberosum L; Stomata atropism; Unipolar germination