tomato salt response

Wild halophytic tomato has long been considered as an ideal gene donor for improving salt tolerance in tomato cultivars. Here, a wild tomato genotype, Solanum pimpinellifolium ‘PI365967’ is significantly more salt-tolerant than a cultivar, Solanum lycopersicom ‘moneymaker’. Affymetrix Tomato Genome Arrays was used to compare the transcriptome change of PI365967 and Moneymaker by salt treatment.After treatment with 200 mM NaCl for 5 h, PI365967 showed relatively fewer responsive genes compared to Moneymaker. Salt Overly Sensitive (SOS) pathway was found to be more active in PI365967 than in Moneymaker, coinciding with relatively less accumulation of Na+ in shoots of PI365967. A gene encoding salicylic acid-binding protein 2 (SABP2) was induced by salinity only in PI365967, suggesting a possible role of salicylic acid signaling in salt response of PI365967. The fact that two genes encoding lactoylglutathione lyase were salt-inducible only in PI365967, together with much higher basal expression of several glutathione S-transferase genes, suggested a more effective detoxification system in PI365967. Key words: salt tolerance, transcriptomic profiling, wild tomato, ion homeostasis, SABP2. In one treatment, 9 six-leaf-old plants of one tomato genotype (PI365967 or Moneymaker) were divided into three biological replicates and treated hydroponically under sterile condition with (or without) 200 mM NaCl for 5 h. RNA isolated from pooled three individual plants was used in hybridization to one chip, resulting in 12 chips in total.