Establishment of stable long-term photomixotrophic cell cultures of tobacco ( Nicotiana Tabacum L.)

Abstract

Photomixotrophic cell cultures of tobacco, Nicotiana tabacum L. were established from hypocotyl and cotyledon explants of burley and cigar tobacco cultivars. Tissues of cigar-type tobacco had higher chlorophyll (chl) content than burley cultivars. Callus from hypocotyls of the cigar-type tobacco cultivars had a higher chl content than callus from cotyledon explants. The greening response was not a transient phenomenon, and after 3 years of culture, the cells had maintained their green phenotype. Callus grown on medium containing 0.5% sucrose had higher chl content and lower fresh weight (FW) than callus grown on medium containing 2% sucrose. The effects of two light intensities and five sucrose concentrations of FW and chl content, as well as the interaction between the effects of light and sucrose, were highly significant. Cultures under high light intensity had significantly greater FW increase and chl content than those under low light intensity. The correlation between sucrose content and photoassimilation was negative and highly significant ( r = −0.98). With increasing sucrose concentration, photoassimilation contributed less to FW increase.