Gene expression of halophyte Kosteletzkya virginica seedlings under salt stress at early stage

Gene differential expression of Kosteletzkya virginica seedlings under salt stress at two time points (2, 24 h) in roots and leaves was analyzed using the cDNA-amplified fragment length polymorphism (cDNA-AFLP) technique. Polymorphic transcript-derived fragments (TDFs) among control plants and salt-treated plants were grouped into four main differential expression patterns: repression (A), de novo induction (B), up-regulation (C) and down-regulation (D). Among them, 34 differentially expressed gene fragments were homologous to known genes from other species and 4 were sequences with unknown functions. These differentially expressed genes can be classified into four groups according to their putative functions: (1) genes for re-establishing ion homeostasis and protecting the plant from stress damage; (2) genes involved in metabolism or energy and resuming plant growth and development under salt stress; (3) genes involved in regulation of gene expression; (4) genes for signal transduction. Changes of eight differentially expressed genes were confirmed by quantitative real time RT-PCR.