Primarily, lithium (Li) resource development and wider application of Li-ion batteries result in Li pollution and concomitantly poses increasing and inevitable problems to environmental health and safety. However, information is rare about the scope of the remediation of Li contaminated soil. Apocynum venetum is already proved to be a Li-accumulator with high Li tolerance and accumulation (Jiang et al., 2014). However, it is not clear whether Apocynum pictum, another species of the same genus with the same uses as A. venetum, is also a Li-accumulator. We investigated germination, growth and physiological responses of A. pictum to different levels of LiCl. Germination was not significantly affected by low Li concentration (0–100 mmol L−1). As LiCl increased from 100 to 400 mmol L−1, both germination percentage and index decreased gradually. For germination of A. pictum seeds, the critical value (when germination percentage is 50%) in LiCl solution was 235 mmol L−1, and the limit value (when germination percentage is 0%) was 406 mmol L−1. A. pictum1,800 mg kg−1 Li in leaves, and still survived under 400 mg kg-1 Li supply. The high Li tolerance of A. pictum during germination and growth stage was also reflected by activity of α-amylase and contents of soluble sugar, proline and photosynthetic pigments under different Li treatments. The bioconcentration factors (BCF) (except control) and translocation factors (TF) were higher than 1.0. High tolerance and accumulation of Li indicated that A. pictum is Li-accumulator. Therefore, this species could be useful for revegetation and phytoremediation of Li contaminated soil.

Two novel peptides belonging to the dermaseptin family, namely DRS-CA-1 and DRS-DU-1, were encoded from cDNA libraries derived from the skin secretions of Phyllomedusa camba and Callimedusa (Phyllomedusa) duellmani. Both natural peptides are highly-conserved and exhibited high potency against wild-type Gram-positive, Gram-negative bacteria, yeast and antibiotic-resistant bacteria (MRSA and Pseudomonas aeruginosa) (MICs 4–8 µM) with no obvious hemolytic activity. Collectively these results suggest that both peptides may have potential as novel antibiotics. Additionally, DRS-DU-1 exhibited selective cytotoxicity to tumor cells. The truncated analogue, DP-1 and TAT-fused DP-1 (namely DP-2) were subsequently synthesised. It showed that DP-1 had low antimicrobial activity, no hemolytic and cytotoxicity to tumor cells. However, DP-2 possessed strong antimicrobial activity and the similar selective, no obvious hemolytic activity and cytotoxicity on normal human cells, but enhanced cytotoxicity to tumor cells of DRS-DU-1. These findings indicate that the N-terminus of the dermaseptins may contribute to their bioactivity, and that addition of the TAT peptide can improve biological activity. The results provide a new insight for designing novel peptide-based antimicrobial or anticancer agents with low hemolytic activity and cytotoxicity.

Excluding grazers is one of most efficient ways to restore degraded grasslands in desert-steppe communities, but may negatively affect the recovery of plant species diversity. However, diversity differences between grazed and fenced grasslands in desert-steppe are poorly known. In a Stipa breviflora desert steppe community in Northern China, we established six plots to examine spatial patterns of plant species diversity under grazed and fenced conditions, respectively. We addressed three aspects of species diversity: (1) The logistic, exponential and power models were used to describe the species-area curve (SAR). Species richness, abundance and Shannon diversity values change differently with increasing sampling areas inside and outside of the fence. The best fitted model for SAR was the logistic model. Excluding grazers had a significant impact on the shape of SAR. (2) Variograms was applied to examine the spatial characteristics of plant species diversity. We found strong spatial autocorrelations in the diversity variables both inside and outside the fence. After grazing exclusion, the spatial heterogeneity decreased in species richness, increased in abundance and did not change in Shannon diversity. (3) We used variance partitioning to determine the relative contributions of spatial and environmental factors to plant species diversity patterns. Environmental factors explained the largest proportion of variation in species diversity, while spatial factors contributed little. Our results suggest that grazing enclosures decreased species diversity patterns and the spatial pattern of the S. breviflora desert steppe community was predictable.