Biochemical Characterization and Differential Expression of PAL Genes Associated With “Translocated” Peach/Plum Graft-Incompatibility

• DOI: 10.3389/fpls.2021.622578
• Publication Date: 2021-02-20T22:05:15Z
• Authors: Rihab Amri; Carolina Font i F...; Rosa Giménez; Ana Pina; María Ángeles Moreno
• Keywords: Phenylpropanoid; Phenylalanine ammonia-lyase

Grafting is an ancient plant propagation technique widely used in horticultural crops, particularly fruit trees. However, the involvement of two different species grafting may lead to lack affinity and severe disorders between graft components, known as graft-incompatibility. This complex agronomic trait traditionally classified into categories: “localized” (weak unions with breaks cambial vascular continuity at interface absence visual symptoms scion leaves shoots) “translocated” (degeneration sieve tubes phloem companion cells causing translocation problems neighboring tissues, reddening/yellowing leaves). Over decades, more attention has been given mechanisms underlying type graft-incompatibility; whereas phenylpropanoid-derived compounds differential gene expression associated graft-incompatibility remain unstudied. Therefore, aim this study was shed light on biochemical molecular involved typical peach/plum graft-combinations. In study, “Summergrand” (SG) nectarine cultivar budded plum rootstocks: “Adara” “Damas GF 1869”. “Translocated” incompatibility were shown biochemically characterized case “SG/Damas 1869” graft-combination, 3 years after grafting. Non-structural carbohydrates (soluble sugars starch), phenolic antioxidant activity, significantly enhanced incompatible graft-combination scion. Similarly, enzymatic activities enzyme peroxidase, phenylalanine ammonia-lyase (PAL) polyphenol oxidase phenylpropanoid pathway affected by rootstock 1869”, inducing higher than those induced compatible “Adara”. addition, a positive strong correlation obtained total phenol content, capacity key genes pathway, PAL1 PAL2 . Regarding “SG/Adara” there neither external nor significant differences parameters rootstock, proving it be combination. The PAL together factors cited above could good markers for