Developmentally specific soluble and membrane proteins and glycoproteins in Mammillaria gracillis Pfeiff. (Cactaceae) tissue culture

Artificial environmental conditions in the tissue culture influence growth and induce aberration from the characteristic organization pattern. As CAM plants, cacti are particularly susceptible to altered growth environment. In vitro propagated Mammillaria plants spontaneously produce callus which regenerates normal and hyperhydric shoots without the addition of any growth regulator. In order to compare habituated callus with tumour, cactus cells were transformed with A. tumefaciens. Cactus tumour has never expressed any organogenic potential. The aim of this work was to detect changes in protein and glycoprotein profiles in different developmental stages of Mammillaria tissues. Proteins were separated by SDS-PAGE and silver stained. Glycoproteins were detected according to their affinity to Con A, while the glycan components were further characterized with lectins GNA, DSA, MAA, PNA and SNA. Only few morphogenesis-specific polypeptides were observed on the gels. Differences were more pronounced in the glycoprotein pattern. The greatest number of glycosylated proteins in all cactus tissues was detected by Con A, according to which all untransformed tissues were characterized by the presence of 40 kDa glycoprotein, while the tumor exhibited some specific protein bands. No signal was observed with DSA, while GNA-, PNA-, MAAand SNA-profiles partially correlated with those detected with Con A. The results demonstrated changes in protein glycosylation related to disarrangement or loss of characteristic tissue organization pattern inMammillaria gracillis tissue culture.