Inducing Plant Defense Reactions in Tobacco Plants with Phenolic-Rich Extracts from Red Maple Leaves: A Characterization of Main Active Ingredients

Forests

Alexandrater Halle¹  HichamEl Alaoui²  Claire Richard³  Samar Hamdache³  Mohamad Sleiman³  Ayhan Kocer⁴  Pascale Goupil⁵  Elodie Peghaire⁵  Antonin Galien⁵ 

[1] UMR CNRS 5623 IMRCP, Université Paul Sabatier, 31062 Toulouse, France;UMR CNRS 6023 LMGE, Université Clermont Auvergne, 63178 Aubière, France;UMR CNRS 6296 ICCF, Université Clermont Auvergne, 63178 Aubière, France;UMR CNRS/INSERM 6293 GReD, Université Clermont Auvergne, 63000 Clermont-Ferrand, France;UMR INRA 547 PIAF, Université Clermont Auvergne, 63178 Aubière, France;

关键词: alkaline hydrolysis;    defense reactions;    gallotannins;    red maple leaf extract;    tobacco;   

DOI  :  10.3390/f11060705

来源: DOAJ

【 摘 要 】

Red maple leaf extracts (RME) were tested for their plant defense inducer (PDI) properties. Two extracts were obtained and compared by different approaches: RME1 using ethanol–water (30–70%, v/v, 0.5% HCl 1N) and RME2 using pure water. Both extracts titrated at 1.9 g L⁻¹ in polyphenols and infiltrated into tobacco leaves efficiently induced hypersensitive reaction-like lesions with topical accumulation of auto-fluorescent compounds noted under UV and scopoletin titration assays. The antimicrobial marker PR1, β⁻¹,3-glucanase PR2, chitinase PR3, and osmotin PR5 target genes were all upregulated in tobacco leaves following RME1 treatment. The alkaline hydrolysis of RME1 and RME2 combined with HPLC titration of gallic acid revealed that gallate functions were present in both extracts at levels comprised between 185 and 318 mg L⁻¹. HPLC-HR-MS analyses and glucose assay identified four gallate derivatives consisting of a glucose core linked to 5, 6, 7, and 8 gallate groups. These four galloyl glucoses possessed around 46% of total gallate functions. Their higher concentration in RME suggested that they may contribute significantly to PDI activity. These findings define the friendly galloyl glucose as a PDI and highlight a relevant methodology for combining plant assays and chemistry process to their potential quantification in crude natural extracts.

【 授权许可】

Unknown