Differential expression of the members of the Asr gene family in tomato (Lycopersicon esculentum)

In this work, we continued to dissect the Asr (ABA/water stress/ripening-induced) gene family originally described in tomato. A RT-PCR-based strategy was developed to assess the organ (leaf, root and fruit) and developmental (immature and ripe fruit) specificity of expression of the three known members of the Asr gene family under normal and stress conditions. Our results allow us to conclude that whereas Asr1 and Asr2 are the members of the family preferentially induced by desiccation in leaves, Asr2 is the only one activated in the roots from water-deficit-stressed plants. We also observed that expression of the three genes does not change significantly in fruit at different developmental stages, except for that of Asr2, which decreases after the breaker yellow stage. In addition, we identified a 72-amino acid polar peptide region, rich in His, Lys, Glu and Ala, which contains two internal imperfect repeats and is highly conserved in more recently discovered Asr-like proteins from other plant species exposed to different kinds of abiotic stress such as water deficit, salt, cold and/or limiting amount of light. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.