Ecological Developmental Adaptability Life Sciences :
Ecological Dynamics


Associate Professor MITSUI Hisayuki
Campus Katahira campus
Laboratory Symbiosis Genomics
Tel +81-22-217-5685
E-mail hisayuki.mitsui.e5@tohoku.ac.jp
1999     Associate Professor, Institute of Genetic Ecology, Tohoku University
2001     Associate Professor, Graduate School of Life Sciences, Tohoku University
Selected Publications
Sugawara M, Takahashi S, Umehara Y, Iwano H, Tsurumaru H, Odake H, Suzuki Y, Kondo H, Konno Y, Yamakawa T, Sato S, Mitsui H, Minamisawa K. 2018 Variation in bradyrhizobial NopP effector determines symbiotic incompatibility with Rj2-soybeans via effector-triggered immunity. Nat Commun 9:3139.
Mitsui H, Minamisawa K. 2017. Expression of two RpoH sigma factors in Sinorhizobium meliloti upon heat shock. Microbes Environ 32:394–397.
Sánchez C, Mitsui H, Minamisawa K. 2017. Regulation of nitrous oxide reductase genes by NasT-mediated transcription antitermination in Bradyrhizobium diazoefficiens. Environ Microbiol Rep 9:389–396.
Sasaki S, Minamisawa K, Mitsui H. 2016. A Sinorhizobium meliloti RpoH-regulated gene is involved in iron-sulfur protein metabolism and effective plant symbiosis under intrinsic iron limitation. J Bacteriol 198:2297–2306.
Anda M, Ohtsubo Y, Okubo T, Sugawara M, Nagata Y, Tsuda M, Minamisawa K, Mitsui H. 2015. Bacterial clade with the ribosomal RNA operon on a small plasmid rather than the chromosome. Proc Natl Acad Sci U S A 112:14343–14347.
Activities in Academic Societies

Japan Society for Bioscience, Biotechnology and Agrochemistry
Japanese Society of Plant Microbe Interactions


Symbiotic Gene Ecology (graduate students)

Joint Lecture on Ecology (graduate students)

Introduction to Life Science (all students)

Recent Activities

Rhizobia are a group of soil bacteria that engage in a nitrogen-fixing symbiosis with leguminous plants. Most of them belong to the class Alphaproteobacteria. This taxon is highly diverse, containing autotrophic, heterotrophic, aquatic, soil-dwelling, plant-symbiotic, and animal-symbiotic bacteria, and is distributed widely across various environments. The taxon also shares a common ancestor with mitochondria. The evolution of alphaproteobacterial diversity can be attributed to their intrinsic adaptability as well as to the lateral transfer of new genes. I am devoted to the (educational) study of key mechanisms underlying the adaptability of rhizobia (and other plant-associated alphaproteobacteria) to stressful environments. One of our research topics is the molecular mechanism of cellular protein turnover and iron-sulfur cluster biogenesis, which are crucial for successful plant infection. My main approaches involve bacterial genetic analysis via isolation of various mutants and molecular analysis using genomic information. I aim to generalize the results from this rhizobium study to understand the primary adaptive mechanism that underlies the diversity of living organisms and their lifestyles.

Message to Students

Enjoy your graduate school life with bacterial genetics.