Selection and mechanism exploration for salt-tolerant genes in tomato

<p>High salinity is a major destructive environmental factor limiting the growth and productivity of plants. In this study, we selected 8 significantly enriched salt stress-related pathways and 17 differentially expressed genes based on RNA sequencing (RNA-Seq). We verified the salt tolerance of the selected key genes using qRT-PCR and combined molecular biology and physiology to explore the salt tolerance mechanism of <i>ASR2-like</i> and <i>ASR3-like</i> genes using the salt-tolerant tomato cultivar LA2711 and the salt-sensitive tomato cultivar ZS-5. The results showed that exogenous ABA significantly increased all physiological indexes but decreased the transcript levels of two target genes compared with untreated controls under salt stress, suggesting that the two genes play an important role in salt tolerance in the form of negative dependence on ABA. Combined with the ABA adaptation pattern and the relationship between the target gene and ABA in the process of response to salt stress, we concluded that <i>ASR2-like</i> and <i>ASR3-like</i> might respond to salt stress by increasing the activities of ROS-scavenging enzymes and proline content via negative dependence on ABA. Taken together, these results provide a good resource for the genetic improvement of tomato and a theoretical basis for obtaining tomato varieties with high resistance to salt.