The biochemical basis for the resistance to aluminum and their potential as selection markers.

Aluminum (Al) toxicity is one of the most widespread agronomic problems in world agriculture. The cellular mechanisms that some plant species use to tolerate Al are still not understood today. This knowledge is essential in order to develop crop species that can be cultivated on acid soils. Plant cell culture has been used for the investigation of both: Al-toxicity and -tolerance. The method used to obtain Al-tolerant cell line will be shown; as well as a protocol to measure Al-free concentration in the culture medium by using Morin (a fluorescent histochemical indicator for Al). Because Al affects different processes involved in the signal transduction pathway such as phospholipase C (PLC) activity, which could serve as selection marker, the PLC activity determination will be introduced.