青岛农业大学

Pear fruit hard-end disorder is a physiological disorder characterized by excessive lignin accumulation at the calyx end, which seriously affects postharvest texture quality and marketability due to excessive lignin accumulation at the calyx end. Although lignification has been recognized as the major cause of hard-end formation, the upstream hormonal signaling mechanisms remain largely unclear. This study demonstrates that the endogenous abscisic acid (ABA) levels were elevated in the calyx-end flesh of hard-end fruits. Further analysis reveals that ABA treatment notably raised the incidence of hard-end disorder, while using an ABA biosynthesis inhibitor reduced its occurrence. In this study, we identified an ABA-responsive regulatory cascade in which PpMYB1R1 directly activates PpNAC187, thereby promoting expression of the lignin biosynthetic gene PpCCR. Functional analysis showed silencing either PpNAC187 or PpMYB1R1 reduced ABA-induced lignin accumulation in pear fruit. Stable transgenic analyses further confirmed the positive regulatory role of PpMYB1R1 in pear lignification. Notably, PpMYB1R1 represents a non-canonical 1R-type MYB transcription factor lacking the conserved EAR repression motif, revealing a previously unrecognized mechanism underlying ABA-mediated lignification during fruit physiological disorder. Collectively, our findings uncover a novel ABA-dependent transcriptional module regulating lignin accumulation during pear hard-end disorder and provide new insights into the molecular basis of fruit physiological disorder in pear.

This study proposes a process that combines acid washing with KOH/PVC synergistic activation to prepare hierarchically micro-mesoporous carbon using coal gasification fine slag (CGFS) and polyvinyl chloride (PVC) as raw materials. When the PVC addition is 0.05 g in the co-alkali activation process, the CO2 adsorption capacity of the adsorbent(The dried HHCGFS was uniformly mixed with KOH and PVC at mass ratios of 1:2:0.05, HH-CGFS-2KOH-0.05PVC) reaches 47.63 cm3/g, and still remains at 23.65 cm3/g at 25 ℃, which is about 6 times higher than that of the unmodified slag. Moreover, the performance decay is less than 3 % after 10 adsorption–desorption cycles. The incorporation of PVC promoted the development of sp2 carbon networks, increasing graphitisation by 24 % while reducing surface oxygen-containing functional groups, thereby endowed the material a delocalised π-electron system. Molecular modelling of the adsorbent via Density Functional Theory(DFT) simulations revealed an adsorption energy of −15.5 kcal/mol, significantly higher than conventional coal-based carbons, indicating adsorption driven by strong electrostatic and van der Waals interactions. This research provides theoretical foundations and demonstrative pathways for synergistic solid waste utilisation and the design of low-cost, high-efficiency carbon capture materials.

Pickering emulsion stabilized by the ovalbumin-gum Arabic polyelectrolyte complex in the presence of gelatin could be spray dried to yield oil microcapsules, but its scalability was restricted by the low total solid concentration of emulsion and the high surface oil content of resultant microcapsules. To address these issues, the effects of gelatin and maltodextrin addition conditions on the spray drying of resultant tuna oil emulsion were investigated. The results indicated that the addition of gelatin decreased the emulsion viscosity, which could be related to its weakened network structure and capillary force according to Cryo-SEM observation, and a low Bloom value among 100 g, 150 g, and 250 g favored this effect, but a moderate value (150 g) conferred the lowest surface oil content to the resultant powder; besides, the addition of maltodextrin further decreased the surface oil content to 2.89% and increased the total solid concentration of the emulsion to 45%. The optimized microcapsules exhibited discrete sphere microstructure, faded fishy off-flavor, moderate flowability and wettability, and enhanced stability against thermal treatment and light exposure compared with conventional microcapsule stabilized by ovalbumin. Hence, the scalability of Pickering emulsions in spray drying could be achieved by the addition of extra polyelectrolytes and maltodextrin.

Coagulant selection critically governs the structural development and functionality of plant protein gels. This study systematically investigated the heat-assisted (85 °C, 1 h) gelation behavior of pea protein induced by CaSO4, MgCl2, and glucono-δ-lactone (GDL) at 0-1.4% (w/w) concentrations using rheological and multiscale structural analyses. All systems underwent a sol–gel transition, yet distinct network development pathways were observed. CaSO4 and GDL formed continuous three-dimensional networks, whereas MgCl2 primarily promoted clustered aggregation with limited formation of a percolated network. At optimal concentrations, GDL produced the strongest gel (hardness 58.08 g) with the highest water-holding capacity (81.89%), followed by CaSO4 (43.60 g, 79.40%), while MgCl2 yielded significantly weaker gels (22.17 g, 78.19%). Secondary structure analysis revealed increased β-sheet content across treatments, indicating aggregation associated with heat-induced conformational rearrangement. Small-angle X-ray scattering further demonstrated coagulant-dependent fractal characteristics: Ca2+ favored densely crosslinked networks, Mg2+ promoted clustered mass-fractal aggregates, and GDL generated compact structures through gradual acidification. Variations in fractal characteristics and network connectivity were consistent with differences in storage modulus and macroscopic gel strength. Collectively, the results establish a coagulant-dependent structure-function framework for heat-assisted pea protein gelation and provide mechanistic guidance for texture optimization in plant-based gel systems.

In deciduous woody plants, buds enter endodormancy in late autumn, and endodormancy release (EDR) is a essential for regrowth. In tree peony, endodormancy is a major obstacle to forcing culture, an important component of its industry. Both chilling accumulation and gibberellin acid (GA) application can contribute to break dormancy and facilitate bud sprouting and flowering under appropriate conditions. PsmiR159b is one of the most abundant miRNAs in dormant buds, targeting PsMYB65 to inhibit bud EDR. Here, PsGA2ox2 was identified as a novel target of PsmiR159b according to expression data and genetic analysis. PsGA2ox2 expression was up-regulated by prolonged chilling, following with an increase of gibberellic acid 34 (GA34), a product of deactivated GA4 by GA2-oxidase. Silencing of PsGA2ox2 accelerated budbreak, accompanied by the increase of GA1 and GA4, downregulation of PsABI5, PsSVP, and upregulation of PsEBB1, PsEBB3, and PsCYCD. The content of GA4 was downregulated in STTM159b buds, whereas increased in MIR159b-OE buds. In addition, the ectopic expression of PsGA2ox2 in Arabidopsis dramatically delayed seed germination and inhibited plant growth. These findings indicated a dual-target regulatory role for PsmiR159b in regulating GA homeostasis, and also revealed a PsmiR159b-PsGA2ox2 module that influenced EDR in tree peony through bioactive GA level regulation.