Zinc and selenium as modulating factors of the anatomy and physiology of billbergia zebrina (Bromeliaceae) during in vitro culture

Abstract

Deleterious effects induced by high zinc (Zn) concentrations can be alleviated with selenium (Se) co-exposure. Therefore, we analyzed the morphophysiological changes of Billbergia zebrina in response to Zn and Se co-exposure. Plants were cultured in media containing three Zn concentrations (0, 30, and 300 μM) combined with two Se concentrations (0 and 4 μM), for a total of six treatments. At 75 d of culture, the leaf anatomy, chlorophyll (Chl) a fluorescence, and contents of photosynthetic pigments (Chl) and nutrients were analyzed. The total Chl content declined with rising Zn concentrations. Plants cultured with Se presented a decrease in the Chl a/b ratio and greater total Chl content. Positive L-and K-bands were verified under Se absence and with 30 and 300 μM Zn. Plants showed bioaccumulation capacity and tolerance to excess Zn. Se acted as a modulator to alleviate the Zn stress.