Tsune Kosuge

He was a professor in the department of plant pathology at the University of California, Davis, from 1971 until his death, serving as departmental chair (1974–80).

His PhD in comparative biochemistry was from the University of California, Berkeley (1959); his supervisor was Eric Conn.[1][2][3][4] In 1961, he joined the plant pathology department at the University of California, Davis, where he remained until his death, becoming a professor in 1971 and serving as departmental chair in 1974–80.

This work included the earliest experimental demonstration of the important enzyme phenylalanine ammonia-lyase, which regulates phenylpropanoid metabolism.

[2][3][4] In research described by the National Academy of Sciences as "meticulous",[4] he dissected in detail the enzymes used by the bacterium to produce IAA.

He later showed that the genes are similar in sequence to those of Agrobacterium tumefaciens, which causes crown gall disease, and are encoded in T-DNA.