Bioeffector Pseudomonas fluorescens ZX Elicits Biosynthesis and Accumulation of Functional Ingredients in Citrus Fruit Peel: A Promising Strategy for a More Sustainable Crop

Abstract

Preharvest application of biocontrol agents is a promising strategy for promoting biosynthesis and accumulation of functional ingredients in fruit crops. In this study, we sought to evaluate the potential of Pseudomonas fluorescens ZX in stimulating the primary and secondary metabolism of citrus fruit peel. Pretreatment with P. fluorescens ZX was found to significantly affect the concentrations and profiles of both primary and secondary metabolites. More importantly, using P. fluorescens ZX suspension to increase inoculation numbers during fruit development typically elicited stronger stimulus effects, and multiple applications of P. fluorescens ZX significantly improved the biosynthesis process of beneficial compounds, resulting in their abundant accumulation in the peel. In fruit pretreated four times with P. fluorescens ZX, hesperidin, sinensetin, nobiletin, synephrine, and pectin were increased by approximately 26.0, 31.3, 44.8, 19.7, and 23.1%, respectively, compared to the untreated control. Collectively, these results indicated that, as a biostimulant, preharvest application of P. fluorescens ZX is an effective, affordable, ecological, and ecofriendly alternative agricultural technique for exploiting citrus crops. This approach is also promising for increasing the value of citrus fruit peel (currently regarded primarily as processing waste), thereby allowing industrial agricultural practices to move one step closer toward a circular economy.

Comprehensive study on nutritional, flavour and metabolite characteristics of green prickly ash (Zanthoxylum schinifolium) at different picking stages

“…Free amino acid contents were determined following previous work with slight modifications (Wang et al ., 2021). Sample powder (0.5 g) was mixed with 10 mL sulphosalicylic acid (40 g/L), and then fully incubated and homogenised at 4°C.…”

Optimization and comparison of nonconventional extraction techniques for soluble phenolic compounds from brocade orange (Citrus sinensis) peels

“…The profiles of individual phenols of FPs, EBPs, and GBPs were determined qualitatively and quantitatively using an ultra-HPLC (UHPLC) coupled with a quadrupole time of flight mass spectrometry (Q-TOF-MS) (Impact II 10,200, Bruker, Germany) and an HPLC (1260, Agilent, Santa Clara, CA, USA) coupled with a diode array detector (DAD) (G1315B, Agilent), respectively, the same to our previously published method (Wang, Chen, Guo, et al, 2022;Wang, Chen, Zhong, et al, 2021). Briefly, chromatographic separation of the three forms of phenolic compounds (1 µl) was conducted on an Agilent Eclipse Plus C18 column at 35 • C. Mobile phases consisted of 1 ml/L (v/v) formic acid (solvent A) and methanol (solvent B) at the flow rate of 0.30 ml/min.…”