Yet, pathogenicity of plants often appeared to be light-dependent (Bonomi et al. 2016; Río-Álvarez et al. 2014; McClung 2011), and it has been known for decades that plant microbial pathogens display diurnal rhythms of infection activity (Martinez-Bakker and Helm 2015; Sreeramulu 1959) while the intact circadian clock was found to be essential for virulence of Botrytis cinerea (Hevia et al. 2015). The gene discussed is CLOCK; the disease is infection.