Mechanism Exploration Of Tomato ASR-like Genes In Response To Salt Stress Based On RNA-seq

Plants are exposed to high salinity environmental stress,which could adversely affect the growth and productivity of plants.Many important function genes play important role of salt tolerance in tomato.In the current study,salt tolerance physiological indexes were analyzed during tomato germination stage and seedling stage.We screened the salt tolerance target genes through RNA-seq analysis of the seedlings under the optimal treatment conditions.In addition,we verified the salt tolerance of the selected target gene and explored the salt tolerance mechanism of ASR2-like and ASR3-like by using two different kinds of tomato related to salt stress.This study provide theoretical basis for obtaining salt tolerance of tomato varieties.The results are as follows:(1)Each indicator is closely related to salt concentration during tomato germination stage and seedling stage.With the increase of salt concentration,the germination rate,germination potential,germination index,radicle long,root weight,plant height and leaf numbers significantly decrease.Antioxidant enzymes activities first increase and then decrease with the increasing of salt concentration and treatment time.TOPSIS analysis suggested that 200 mM and 19 d are the optimum salt treatment conditions for the identification of salt tolerance in tomato.(2)Based on RNA-Seq,a total of 3792 differentially expressed genes were detected in the process of response to salt stress.Among these differentially expressed genes,2776 were involved in the biological metabolic processes.We screened 17,19 and 17 key genes in 7 protein metabolic,6 carbohydrate metabolic and 8 salt stress related pathways respectively.We chose some of the key genes for verrification by qPCR.The results showed that the expression trends of these genes were the same to RNA-Seq.ASR2-like and ASR3-like were chose to be target genes for salt tolerance mechanism exploration.A complete bioinformatics analysis of the two genes in tomato was performed.(3)Function pattern of ABA adaption to salt stress were analyzed using six physiological indexes in salt-tolerant tomato and salt-sensitive tomato under four kinds of treatments,seven time and three tomato parts.The expressions of ASR2-like and ASR3-like were also analyzed under these conditions,suggesting that two genes play important role of salt tolerance in the form of negative dependence on ABA.Combined with the ABA adaption pattern and the relationship between target genes and ABA in the process of response to salt stress,we concluded that ASR2-like and ASR3-like might response to salt stress by increasing the activities of ROS-scavenging enzymes and proline content in the form of negative dependence on ABA.