A phytoexclusion strategy for reducing contamination risk of rice based on low-Cd natural variations pyramid of root transporters.

Cadmium pollution in rice is a threat to human health. Phytoexclusion is an effective strategy to reduce the Cd accumulation. Soil-to-root is the first step of Cd entering rice and plays a crucial role in Cd accumulation, so targeting root transporters could be an effective approach for phytoexclusion. This study utilized single-gene & multi-gene joint haplotype analysis to reveal the law of natural variations. The result showed that natural variations of rice root transporters assembled regularly following a certain pattern, rather than randomly. A total of 3 dominant nature variation combinations with 2 high-Cd combinations and 1 low-Cd combination were identified. In addition, indica-japonica differentiation was observed, with indica germplasms harboring high-Cd combinations while japonica germplasms harboring. In Chinese rice landraces, most of the collected indica landraces contained high-Cd combinations, indicating a high Cd contamination risk in indica landraces in terms of both phenotype and genotype. To address this issue, multiple superior low-Cd natural variations were pyramided to create two new low-Cd germplasms. In both pond and farmland trials, the ameliorated rice grain Cd did not exceed safety standards. This research provided a framework for future phytoexclusion, thus to reduce Cd-contamination risk in soil-rice system.

Wallerian degeneration after peripheral nerve injury: research advance in nerve conduits / 中国组织工程研究

BACKGROUND: How to promote the regeneration after peripheral nerve injury, especially after large defects, is a difficulty to be solved.OBJECTIVE: To review the mechanism of Wallerian degeneration and the development of nerve conduits.METHODS: PubMed database was searched for the literatures addressing the modular mechanism of Wallerian degeneration and nerve repair using the English keywords peripheral nerve regeneration, Wallerian degeneration, nerve guidance conduits. A total of 74 eligible literatures were included based on the exclusion criteria.RESULTS AND CONCLUSION: Rat SARM1 and fruit fly dSARM have been found to be highly implicated in Wallerian degeneration, indicating that the changes of nicotinamide adenine nucleotide/nicotinamide adenine dinucleotide may be related to the activated SARM1. Whether delaying Wallerian degeneration is good or bad is still in dispute. The future study should focus on the early inhibition of Wallerian degeneration and promotion of neuroregeneration following peripheral nerve injury.