This book includes papers from keynote lecture and oral presentations of Plant and Microbe Adaptations to Cold (PMAC) 2012, an international conference on winter hardiness of crop and pathogenic microbes. The PMAC has been started in 1997 in Japan as an interdisciplinary forum for scientists and extension people working in the field in plant pathology, plant physiology, microbiology, and crop breeding to increase our knowledge and improve our understanding of overwintering of crops, forages and grasses and solve the problems associated with losses due to freezing and heavy snow cover. Successive meetings have been held in Iceland (2000), Canada (2003), Italy (2006), and Norway (2009). PMAC2012 will be a special meeting with a focus on global climate change, food security and agriculture sustainability and the whole program will be arranged to reflect this theme. The topics covered by this proceedings includes, global warming in agricultural environment, plant adaptations to cold, microbial adaptations to cold, plant-microbe interaction under cold, and molecular breeding for winter hardiness. The researches range from molecular biology to ecology and breeding. Experts in the field will report cutting edge research and thoughtful strategies for sustainability.