A hydroponic system was used to evaluate atrazine (ATZ) removal and uptake by three emergent hydrophytes, Iris pseudacorus, Lythrum salicaria and Acorus calamus, determining their potential as phytoremediation agents for ATZ-contaminated water. After 20 days of exposure, the relative growth rate of plants in sterile conditions was less than in natural conditions. ATZ amount in a culture solution planted with emergent plants decreased significantly compared with an unplanted solution, and the removal rate of ATZ in natural conditions was greater than in sterile conditions (p < 0.05). The degradation contributions of I. pseudacorus, L. salicaria and A. calamus were 75.6, 65.5 and 61.8%, respectively. Those of the corresponding microbial population in the solution were 5.4, 11.4 and 17.4%, respectively. Emergent plants play a dominant role in reducing the ATZ level in the water body and could be used as phytoremediation agents.

To provide more insights into the responses of the soil seed bank and vegetation to human disturbance intensity, we selected four land use types, including: native grassland (no human disturbance), abandoned artificial grassland (light human disturbance), artificial grassland (moderate human disturbance), and farmland (severe human disturbance) in a semi-arid climate of northern China. The species composition and density of the soil seed bank were measured, as well as the species composition and amount of vegetation. The native grassland had a significantly higher soil seed density and species richness than the other land use types. Moreover, the common species both in the soil seed bank and vegetation between the native grassland and other land use types gradually decreased as disturbance intensity increased. The abandoned artificial grassland and artificial grassland still had abundant soil seed banks according to their seed density (≥28.2% of the native grassland) and species richness (≥70.0% of the native grassland) to restore the vegetation. Conversely, it was hard to restore the vegetation on the farmland due to its low soil seed density (10.0% of the native grassland) and species richness (40.0% of the native grassland). In conclusion, human disturbance would generate significant negative effects on the soil seed bank in desertified regions in a semi-arid climate; however, the soil seed bank in land use types with light/moderate disturbance are more adapted to vegetation restoration compared with land use types with severe disturbance in a semi-arid region.

The recretohalophyte Karelinia caspia is of forage and medical value and can remediate saline soils. We here assess the contribution of primary/secondary metabolism to osmotic adjustment and ROS homeostasis in Karelinia caspia under salt stress using multi‐omic approaches. Computerized phenomic assessments, tests for cellular osmotic changes and lipid peroxidation indicated that salt treatment had no detectable physical effect on K. caspia. Metabolomic analysis indicated that amino acids, saccharides, organic acids, polyamine, phenolic acids, and vitamins accumulated significantly with salt treatment. Transcriptomic assessment identified differentially expressed genes closely linked to the changes in above primary/secondary metabolites under salt stress. In particular, shifts in carbohydrate metabolism (TCA cycle, starch and sucrose metabolism, glycolysis) as well as arginine and proline metabolism were observed to maintain a low osmotic potential. Chlorogenic acid/vitamin E biosynthesis was also enhanced, which would aid in ROS scavenging in the response of K. caspia to salt. Overall, our findings define key changes in primary/secondary metabolism that are coordinated to modulate the osmotic balance and ROS homeostasis to contribute to the salt tolerance of K. caspia.