MicroRNAs play important roles in regulating the rapid growth of the Phyllostachys edulis culm internode.

Moso bamboo (Phyllostachys edulis) is a fast-growing species with uneven growth and lignification from lower to upper segments within one internode. MicroRNAs (miRNAs) play a vital role in post-transcriptional regulation in plants. However, how miRNAs regulate fast growth in bamboo internodes is poorly understood. In this study, one moso bamboo internode was divided during early rapid growth into four segments called F4 (bottom) to F1 (upper) and these were then analysed for transcriptomes, miRNAs and degradomes. The F4 segment had a higher number of actively dividing cells as well as a higher content of auxin (IAA), cytokinin (CK) and gibberellin (GA) compared with the F1 segment. RNA-seq analysis showed DNA replication and cell division-associated genes highly expressed in F4 rather than in F1. In total, 63 miRNAs (DEMs) were identified as differentially expressed between F4 and F1. The degradome and the transcriptome indicated that many downstream transcription factors and hormonal responses genes were modulated by DEMs. Several miR-target interactions were further validated by tobacco co-infiltration. Our findings give new insights into miRNA-mediated regulatory pathways in bamboo, and will contribute to a comprehensive understanding of the molecular mechanisms governing rapid growth.

Novel recyclable deep eutectic solvent boost biomass pretreatment for enzymatic hydrolysis.

Deep eutectic solvent (DES) with protonic acid shows the great potential for biomass valorization. However, the acid corrosion and recycling are still severe challenges in biorefinery. Herein, a novel DES by coordinating FeCl3 in choline chloride/glycerol DES was designed for effective and recyclable pretreatment. As compared to DESs with FeCl2, ZnCl2, AlCl3 and CuCl2, DES with FeCl3 approvingly retained most of cellulose in pretreated Hybrid Pennisetum (95.2%). Meanwhile, the cellulose saccharification significantly increased to 99.5%, which was six-fold higher than that of raw biomass. The excellent pretreatment performance was mainly attributed to the high removal of lignin (78.88 wt%) and hemicelluloses (93.63 wt%) under the synergistic effect of Lewis acid and proper hydrogen-bond interaction of DES with FeCl3. Furthermore, almost all cellulose still can be converted into glucose after five recycling process. Overall, the process demonstrated designed pretreatment was great potential for the low-cost biorefinery and boost the biofuel development.

[Study on genetic diversity of Curcuma wenyujin from various habitats by SRAP].

OBJECTIVE: The DNA fingerprints of Curcuma wenyujin from various habitats were generated by using SRAP markers to find the feasibility in analyzing their relationship. METHODS: The DNA polymorphism of Curcuma wenyujin from various habitats were detected by SRAP molecular markers. RESULTS: We had screened five pairs of primer combinations, and built the DNA fingerprints of Curcuma wenyujin from various habitats. The phylogenetic clustering results revealed that the genetic difference in Curcuma wenyujin from various habitats were little. CONCLUSION: SRAP markers may offer some evidence for protecting and exploiting of Curcuma wenyuji.