The use of 2D-DIGE to understand the regeneration of somatic embryos in avocado.

Avocado embryogenic cell cultures can be classified into two groups based on their morphology when cultured on a medium containing auxin: somatic embryo (SE) and proembryonic masses (PEM) type cultures. The calli of SE-type cell lines are able to go through the maturation process, whereas the calli of PEM cell lines rarely mature. We have investigated four independent avocado cell cultures (two SE and two PEM). The aim of this study was to link the differential regeneration capacity of the four cell cultures to a proteomic pattern and to gain insight into the regeneration capacity. A 2D-DIGE analysis followed by a blind multivariate analysis was able to separate the two SE lines from the PEM lines indicating that the protein profiles of SE and PEM calli are different. Based on the variable importance, that is, the differential protein pattern, we hypothesize that the regeneration capacity in avocado is correlated to the ability to overcome the physicochemical stress stimuli associated with the in vitro culture. Our identical culture conditions do not seem to trigger an appropriate response in PEM lines.