Drought stress caused by continuous global warming poses a severe challenge to the growth and development of Nitraria tangutorum. Abscisic acid has an important regulatory function in the process of plants responding to drought stress. This study took the N. tangutorum seedlings of Zhangye provenance 2-17-16 genealogy as the research object to explore the physiological mechanism of how different concentrations of exogenous ABA alleviate drought damage in N. tangutorum. The results showed that exogenous ABA could promote the growth and increase the leaf relative water content of N. tangutorum seedlings under drought stress. It alleviates the photosynthetic inhibition phenomenon of N. tangutorum seedlings under drought stress by regulating the photoprotective mechanism and energy distribution efficiency of photosystem II. It also alleviates the drought damage of N. tangutorum by increasing the content of osmotic-adjustment substance contents such as soluble sugar, soluble protein, proline, and starch, as well as enhancing the activity of antioxidant enzymes such as POD, SOD, and CAT. The comprehensive analysis showed that 20 μM and 30 μM ABA have the best alleviating effects on the drought damage of N. tangutorum seedlings. This study provides a theoretical basis for the restoration, propagation, and protection of N. tangutorum, and it is of great significance for maintaining the balance and stability of desert ecosystems.

This work aims at studying the molecular mechanisms underlying the response of Reaumuria soongorica to salt stress. We used RNA sequencing (RNA-Seq) and Tandem Mass Tag (TMT) techniques to identify differentially expressed genes (DEGs) and differentially expressed proteins (DEPs) in R. soongorica leaves treated with 0, 200, and 500 mM NaCl for 72 h. The results indicated that compared with the 0 mM NaCl treatment group, 2391 and 6400 DEGs were identified in the 200 and 500 mM NaCl treatment groups, respectively, while 47 and 177 DEPs were also identified. Transcriptome and proteome association analysis was further performed on R. soongorica leaves in the 0/500 mM NaCl treatment group, and 32 genes with consistent mRNA and protein expression trends were identified. SYP71, CS, PCC13-62, PASN, ZIFL1, CHS2, and other differential genes are involved in photosynthesis, vesicle transport, auxin transport, and other functions of plants, and might play a key role in the salt tolerance of R. soongorica. In this study, transcriptome and proteome association techniques were used to screen candidate genes associated with salt tolerance in R. soongorica, which provides an important theoretical basis for understanding the molecular mechanism of salt tolerance in R. soongorica and breeding high-quality germplasm resources.