Stigma peroxidase activity in association with thermogenesis in Nelumbo nucifera

Stigma receptivity of the protogynous lotus (Nelumbo nucifera Gaertn.) was assessed throughout flowering with a technique that quantified oxygen release from hydrogen peroxide under the influence of stigma surface peroxidase. Both receptivity and heat production increased significantly on the day prior to petal opening, remained high while the stigmas were accessible, and decreased sharply when the pollen was exposed.