Adventitious rooting is an important plant physiological response utilized in cutting propagation, a procedure with high financial significance. Many endogenous factors are involved, such as plant growth regulators, carbohydrates, minerals, polyamines etc. The objective of the present study was to investigate the role of polyamines and polyamine catabolic enzymes in the bases of softwood cuttings of two Prunus rootstocks, during the early phases of rhizogenesis. An easy-to-root and a difficult-to-root rootstock were studied, concerning their polyamine content (in free, soluble conjugate and insoluble bound form), polyamine catabolic enzyme activities (polyamine oxidase, PAO and diamine oxidase, DAO) and catalase activity, with and without the effect of indole-3-butyric acid as rooting hormone, during the early phases of rhizogenesis. Putrescine, spermine and their catabolic product, H2O2, were applied to test their function to rescue the rooting percentage of the recalcitrant species. Spermine was not detected in the difficult to root rootstock, which exhibited higher titer of putrescine and spermidine, PAO and catalase activity, but lower DAO activity compared to the easy-to-root one. The rooting percentage of the recalcitrant species was doubled under spermine and H2O2 application. The results obtained, highlighted the role of polyamine catabolic enzymes and indirectly the role of the polyamine catabolic product H2O2 as more significant than the polyamine content per se in adventitious rooting of the specific stone fruit rootstocks.

中文翻译：

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即使在内源多胺滴度较高的情况下，多胺分解酶在两种生根能力不同的核果砧木高效不定根中可能存在的瓶颈效应


不定根是用于插条繁殖的重要植物生理反应，这一过程具有很高的经济意义。涉及许多内源因素，如植物生长调节剂、碳水化合物、矿物质、多胺等。本研究的目的是研究多胺和多胺分解代谢酶在两种李属砧木的软木插条基部中的作用，在早期根发生阶段。研究了易生根和难生根砧木的多胺含量（游离、可溶性结合物和不溶性结合形式）、多胺分解代谢酶活性（多胺氧化酶、PAO 和二胺氧化酶，DAO）和过氧化氢酶在根发生的早期阶段，无论有或没有作为生根激素的吲哚-3-丁酸的影响，活性。应用腐胺、精胺及其分解代谢产物 H2O2 来测试它们拯救顽固物种生根百分比的功能。难生根砧木中未检测到精胺，与易生根砧木相比，其腐胺和亚精胺滴度、PAO和过氧化氢酶活性较高，但DAO活性较低。在精胺和 H2O2 的施用下，顽固物种的生根百分比增加了一倍。所获得的结果强调了多胺分解代谢酶的作用以及间接多胺分解代谢产物H2O2的作用，其在特定核果砧木的不定生根中比多胺含量本身更显着。