The Influence of Boron Deficiency on Glandular Scale Development and Structure in Mentha piperita

The influence of boron deficiency on glandular scale development in MENTHA PIPERITA was studied under controlled experimental conditions in solution culture. Young leaves of peppermint were examined by light and electron microscope. The differentiation stages of glands from the initial gland cell up to a 10-cell glandular scale were the same in both control and boron-deficient plants. Boron had no influence on the numer of cells in glandular scale development. During gland development a number of ultrastructural alterations occured. The most striking and earliest ultrastructural response to boron deficiency was thickness and irregularity of cell walls. The ultrastructural changes observed in young glands are believed to be senescing phenomena, which normally appear at the postsecretory stage. The acceleration of cell aging during boron deficiency restricts essential oil secretion to a short period.