Comparative Transcriptomic Profiling of a Salt-Tolerant Wild Tomato Species and a Salt-Sensitive Tomato Cultivar

Abstract

Wild halophytic tomato has long been considered as an ideal gene donor for improving salt tolerance in tomato cultivars. Extensive research has been focused on physiological and quantitative trait locus (QTL) characterization of wild tomato species in comparison with cultivated tomato. However, the global gene expression modification of wild tomato in response to salt stress is not well known. A wild tomato genotype, Solanum pimpinellifolium 'PI365967' is significantly more salt tolerant than the cultivar, Solanum lycopersicum 'Moneymaker', as evidenced by its higher survival rate and lower growth inhibition at the vegetative stage. The Affymetrix Tomato Genome Array containing 9,200 probe sets was used to compare the transcriptome of PI365967 and Moneymaker. After treatment with 200 mM NaCl for 5 h, PI365967 showed relatively fewer responsive genes compared with Moneymaker. The 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 for salicylic acid signaling in the 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. The specific down-regulation in PI365967 of a putative high-affinity nitrate transporter, known as a repressor of lateral root initiation, may explain the better root growth of this genotype during salt stress.

Relationship between survival and yield related traits in Solanum pimpinellifolium under salt stress

“…Monforte et al (1997) reported that salt tolerance in S. pimpinellifolium accessions (L1 and L5) is characterized by higher fruit number, total fruit weight and mean fruit weight under saline condition, which is controlled by several QTLs with epistatic and heterotic effects. In contrast, Sun et al (2010) reported that salt tolerance in a S. pimpinellifolium accession (PI365967) is characterized by higher survival rate, lower growth inhibition at the vegetative stage and less accumulation of sodium in shoots with the activation of salicylic acid pathway related genes.…”

The Alleviation of the Adverse Effects of Salt Stress in the Tomato Plant by Salicylic Acid Shows A Time- and Organ-Specific Antioxidant Response

“…Salt tolerance of the cultivated tomato can be significantly enhanced by over-expressing an NHX-type Na + /H + antiporter localized to the vacuolar membrane which enables plants to compartmentalize Na + in the vacuole (Yarra et al, 2012). Comparative transcriptomic profiling of the salt-tolerant S. pimpinellifolium 'PI365967' and the salt sensitive tomato cultivar Moneymaker revealed that a gene encoding SA binding protein 2 (SABP2), which functions in converting methylsalicylate into SA, was induced by salinity only in the wild species (Sun et al, 2010). Genes coding for plasma membrane ATPase1, cell wall peroxidase and cytosolic APX as well as lactoylglutathione lyase involved in methylglyoxal detoxification were up-regulated only in 'PI365967', but other peroxidases and glutathione S-transferases (GSTs) were induced in Moneymaker under salt stress.…”

Comparative Transcriptome Analysis of Two Olive Cultivars in Response to Nacl Stress

“…Such a strategy mainly relies on comparative transcriptome analysis [20] using microarrays. A plethora of comparisons between salt-sensitive and salt-tolerant cultivars of model and non-model plant species such as Arabidopsis [21][22][23], rice [24], tomato [25], poplar [26], potato [27] and sugarcane [28] have been reported up to now. These reports resulted in the identification of more than 30 families of transcription factors comprising DREB, CBF, MYB, bZIP and zing-finger families which are involved in abiotic stress including salinity [29,30].…”