Nucleotide sequence of a root-specific transcript encoding a germin-like protein from the halophyte Mesembryanthemum crystallinum

Following environmental stresses that impair water availability, transcription of a number of genes is induced in the facultative halophyte Mesembryanthemum crystallinum (common ice plant) in aerial parts of the plants. By differential screening of a cDNA library established for mRNAs isolated from roots after 6 h of salt stress, several hundred of either up-regulated or down-regulated mRNAs were indicated. Partial sequencing of a number of these cDNAs suggested putative functions of some cDNAs (for which homologies in the sequence data base were indicated) in signal transduction pathways, in transporting substances or ions across membranes, or in functions that had been implied before to be affected by water balance in plants. An example for the latter function is the sequence of a cDNA for a germin-like protein. Germin is one of a few proteins whose synthesis is induced within hours after the imbibition of dry wheat seeds.