(Gifu University, Japan)

Prof. Hiroyuki Koyama have continuously studied physiological mechanisms of Al and proton tolerance in plants, mostly identified using model plant system. In the early carrier, Prof. Hiroyuki Koyama used carrot mutant cell lines adapted to Al-phosphate medium, and which identified citrate-excretion-dependent P-acquisition mechanism (1990-2000). Next, he identified that Al and proton tolerance mechanisms are controlled by genetically different mechanisms in Arabidopsis (1995-2007). Lastly, he identified a muster switch transcription factor STOP1, which regulates expression of Al and proton tolerance genes in Arabidopsis, but it also regulates hypoxia (positively) and drought tolerance (negatively) in Arabidopsis. These studies were carried out by collaboration with RIKEN, USDA, IITG and other national and international institutions.