Mikhail Chailakhyan
Searching for the internal signal that makes plants flower
Mikhail Chailakhyan was an Armenian plant physiologist associated with the hormonal theory of flowering. Born in Nakhichevan-on-Don in 1902, he pursued an educational and scientific career that took him through Yerevan, Leningrad and Moscow.
He investigated how the duration of light and darkness affects flowering. His experiments highlighted the role of leaves in perceiving day length. In 1936, he introduced the term florigen, proposing that a mobile signal formed in leaves could travel to the growing shoot tip and induce flowers.
Chailakhyan led research on plant growth and development for many years and studied other regulatory processes. Florigen became the focus of a long scientific search; later molecular research identified mobile protein signals involved in flowering. He died in 1991, leaving a research tradition and questions that continued to guide plant biology.