De novo transcriptome analysis of high-salinity stress-induced antioxidant activity and plant phytohormone alterations in Sesuvium portulacastrum.

Sesuvium portulacastrum has a strong salt tolerance and can grow in saline and alkaline coastal and inland habitats. This study investigated the physiological and molecular responses of S. portulacastrum to high salinity by analyzing the changes in plant phytohormones and antioxidant activity, including their differentially expressed genes (DEGs) under similar high-salinity conditions. High salinity significantly affected proline (Pro) and hydrogen peroxide (H2O2) in S. portulacastrum seedlings, increasing Pro and H2O2 contents by 290.56 and 83.36%, respectively, compared to the control. Antioxidant activities, including superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT), significantly increased by 83.05, 205.14, and 751.87%, respectively, under high salinity. Meanwhile, abscisic acid (ABA) and gibberellic acid (GA3) contents showed the reverse trend of high salt treatment. De novo transcriptome analysis showed that 36,676 unigenes were matched, and 3,622 salt stress-induced DEGs were identified as being associated with the metabolic and biological regulation processes of antioxidant activity and plant phytohormones. POD and SOD were upregulated under high-salinity conditions. In addition, the transcription levels of genes involved in auxin (SAURs and GH3), ethylene (ERF1, ERF3, ERF114, and ABR1), ABA (PP2C), and GA3 (PIF3) transport or signaling were altered. This study identified key metabolic and biological processes and putative genes involved in the high salt tolerance of S. portulacastrum and it is of great significance for identifying new salt-tolerant genes to promote ecological restoration of the coastal strand.

[DNA Barcode Screening and Identifying for Anredera cordifolia and Its Related Species].

Objective: To identify Anredera cordifolia and its closely related species using the DNA barcode. Methods: 28 individuals of Anredera cordifolia and its close related species were collected from different habitats. ITS and ITS2 of ribosomal DNA,matK,rbcL and psb A-trn H of chloroplast DNA were amplified and sequenced. The amplification and sequencing success rate,barcoding gap,and NJ trees were used to evaluate the efficiency of species identification. Results: After amplified and sequenced, base deletion was occurred in psb A-trnH sequences of Basella alba. The sequencing success rates of mat K,rbc L,ITS and ITS2 were 100%,100%,78. 75% and64. 28%,respectively. Among the four DNA barcoding sequences,ITS and mat K had remarkable barcoding gap. The NJ tree showed that Anredera cordifolia could differed obviously from its closely related species by ITS and mat K. Conclusion: The sequences of ITS and matK provide an effective and fast tool for the identification and authentication of medicinal plant of Anredera cordifolia and its related species.