Henan University of Technology

The Agrobacterium tumefaciens mediated transformation is the prevailing methodology for plant genetic manipulation; however, A. tumefaciens overgrowth is a common constraint in the process. Exploring auxotrophic A. tumefaciens could reduce overgrowth and enhance plant transformation efficiency. The ILVC gene, which encodes the ketol-acid isomeroreductase, is critical for Valine (Val) and isoleucine (Ile) biosynthesis in some microorganisms. However, its function in A. tumefaciens is unclear. To ascertain the function of ILVC and generate an auxotrophic A. tumefaciens, this study employed an allelic exchange to disrupt the ILVC in A. tumefaciens strain GV3101. This resulted in the loss of ketol-acid isomeroreductase activity and the prevention of Val and Ile biosynthesis, creating a dual-auxotrophic GV3101_∆ILVC. Transient expression assays in Nicotiana benthamiana transformation demonstrated that the GV3101_∆ILVC was capable of T-DNA transfer. Moreover, stable genetic transformation analysis in N. benthamiana indicated that the introduction of GV3101_∆ILVC led to a reduction in overgrowth within infected plant tissues. Additionally, an enhancement in transformation efficiency was observed with the prolongation of the co-cultivation time of the explant-infected strain. This study revealed the function of ILVC and explored a dual-auxotrophic A. tumefaciens for Val and Ile, potentially broadening the utilization of auxotrophic strains in plant genetic transformation.

This article investigates the structure and emulsification properties of peanut protein amyloid fibrils (PAFs) formed at pH 2.0 and different protein concentrations (PC).The findings demonstrated that with an escalation in the PC concentration (10-80 mg/mL), the conversion rate and β-sheet ratio of the fibrils significantly rose, suggesting that the increase in protein concentration promoted the formation of the fibrils.When the concentration was 10 mg/mL, large aggregates and a few short fibrils were formed; when the concentration was 40 mg/mL, more curved fibrils were formed; when the concentration is 60 mg/mL, long curved fibrils were formed; at higher concentrations (80 mg/mL), short and thick fibrils and rigid straight fibrils were formed.This indicates that the morphol. of the fibrils formed under different PCs varies.Addnl., increasing the concentration of PC (10-60 mg/mL) rendered the PAF structure more stable, enhanced the thermal stability, and resulted in a higher emulsification activity index (EAI).When the protein concentration was higher (80 mg/mL), the EAI of the fibrils decreased.This study will intensify the exploration of the concentration-regulated protein fibrillation.

This study evaluated the efficacy of γ-ray irradiation on degrading aflatoxins in peanut press cake, considering the effects of initial aflatoxin levels, irradiation doses and moisture content.The results demonstrated that degradation efficiency peaked and subsequently decreased with increasing aflatoxin content, whereas higher irradiation doses and moisture levels both enhanced aflatoxin degradationMeanwhile, the first-order kinetic model (R² = 0.9799-0.9954) better described aflatoxin degradation than the second-order model.Irradiation had a modest impact on the nutritional and sensory attributes of peanut press cake.It was suggested that a 10 kGy irradiation dose could ensure product quality and effective decontamination when the initial aflatoxin content is around 137 μg/kg to 145 μg/kg, and the moisture content is approx. 11 %.As a non-thermal processing method, γ-ray irradiation effectively reduces mycotoxin levels with less nutritional loss, operational simplicity, and pollution-free environmental sustainability, offering broad application prospects in thermos-sensitive food safety enhancement.