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Summary: Tree peony (Paeonia suffruticosa) undergoes bud endodormancy, and gibberellin (GA) pathway plays a crucial role in dormancy regulation. Recently, a key DELLA protein PsRGL1 has been identified as a negative regulator of bud dormancy release. However, the mechanism of GA signal to break bud dormancy remains unknown.In this study, yeast two‐hybrid screened PsSOC1 interacting with PsRGL1 through its MADS domain, and interaction was identified using pull‐down and luciferase complementation imaging assays Transformation in tree peony and hybrid poplar confirmed that PsSOC1 facilitated bud dormancy release. Transcriptome analysis of PsSOC1‐overexpressed buds indicated PsCYCD3.3 and PsEBB3 were its potential downstream targets combining with promoter survey, and they also accelerated bud dormancy release verified by genetic analysis.Yeast one‐hybrid, electrophoretic mobility shifts assays, chromatin immunoprecipitation quantitative PCR, and dual luciferase assays confirmed that PsSOC1 could directly bind to the CArG motif of PsCYCD3.3 and PsEBB3 promoters via its MADS domain. PsRGL1–PsSOC1 interaction inhibited the DNA‐binding activity of PsSOC1. Additionally, PsCYCD3.3 promoted bud dormancy release by rebooting cell proliferation.These findings elucidated a novel GA pathway, GA‐PsRGL1‐PsSOC1‐PsCYCDs, which expanded our understanding of the GA pathway in bud dormancy release. [ABSTRACT FROM AUTHOR]

Polyamide 6 (PA6) is a widely used thermoplastic engineering polymer, and the toughening modification for PA6 is always a main research topic. Meanwhile, the rigidity and heat resistance of PA6 usually deteriorate. To address this conflict, an epoxy compound (EGDE‐GA) was designed and synthesized and used to modify PA6 by dynamic vulcanization in twin‐screw extruder. EGDE‐GA is a linear molecule with a flexible molecular structure, which is favorable to toughening of PA6, and epoxy groups of EGDE‐GA can form local cross‐linked structure to improve the rigidity and retain the heat resistance of PA6. At the loading of 20 wt% of EGDE‐GA, the modified PA6 (PA6/EGDE‐GA 20) exhibited very high elongation at break and notched impact strength, which were increased by 413% and 520%, respectively, compared to those of PA6. The tensile strength was 61.4 MPa, which was higher than that of PA6. The heat deflection temperature remained almost unchanged. The results showed that the modified polymers may possess the high toughness without sacrificing the original rigidity by building the local crosslinked structure using dynamic vulcanization. The findings provide a feasible method for reusing and upcycling PA6 and other polymers with higher value and wider use in the industry. Highlights: The polyamide 6 (PA6) is toughened via dynamic vulcanization.The toughness of modified PA6 is increased by 520% compared with pure PA6.The toughened PA6 exhibits higher tensile strength than that of pure PA6.The toughened PA6 maintains its rigidity and heat resistance. [ABSTRACT FROM AUTHOR]

The chain extension of polyamide 6 (PA6) via a chemical reaction between a chain extender and the amino and carboxyl groups of the polymer increases the molecular weight and improves the mechanical properties, while typically deteriorates PA6 processability owing to cross‐linking. To resolve this issue, a dynamic covalent chain extender containing two anhydride groups is synthesized, which reacts only with amino groups, and employed to connect the PA6 molecular chains via the reaction between anhydride groups and terminal amino groups of PA6. On adding 3 wt% of the chain extender, the content of amino end groups is decreased from 30.6 to 5.8 μmol g−1 and the yield strength and elastic modulus of chain‐extended PA6 exceed those of original PA6 by 15.8% and 23.4%, respectively; meanwhile, the melt torque of chain‐extended PA6 is lower by 35.0% approximately, and the complex viscosity is also decreased. As far as we know, the dynamic covalent chain extender is used for the first time in the chain extension of PA6. This study provides a prospective approach to recycle PA6 for simultaneously improving mechanical properties and processability. [ABSTRACT FROM AUTHOR]