Hormonal control of the respiratory climacteric in Sauromatum guttatum (Araceae)

A respiratory climacteric (RC) occurs in the appendix (terminal portion of the spadix) of the inflorescence of Sauromatum guttatum Schott during blooming. We have devised purification techniques and a bioassay for calorigen, the compound (synthesized in the staminate flower buds) which triggers the RC in the Sauromatum appendix.Inflorescences were induced to bloom under controlled conditions to determine (1) the time required for calorigen to be released from the staminate flowers and to accumulate in the appendix, and (2) the time required for calorigen to trigger the RC in the appendix. The latter results were confirmed by the direct addition of calorigen to appendix sections in a bioassay.A calorigen-like substance was extracted from the staminate flowers of Arum maculatum, A. italicum, A. dioscoridis, and Dracunculus vulgaris.