Unidad de Biotecnología 1, Instituto de Investigaciones Biotecnológicas-Instituto Tecnológico de Chascomús/Consejo Nacional de Investigaciones Científicas y Técnicas-Universidad Nacional de General San Martín (IIB-INTECH/CONICET-UNSAM), Camino de Circunvalación Laguna, Km 6 CC 164 (B7130IWA), Chascomús, Argentina.
J Plant Physiol. 2011 Jul 15;168(11):1234-40. doi: 10.1016/j.jplph.2011.01.007. Epub 2011 Feb 15.
The possible relationship between polyamine catabolism mediated by copper-containing amine oxidase and the elongation of soybean hypocotyls from plants exposed to NaCl has been studied. Salt treatment reduced values of all hypocotyl growth parameters. In vitro, copper-containing amine oxidase activity was up to 77-fold higher than that of polyamine oxidase. This enzyme preferred cadaverine over putrescine and it was active even under the saline condition. On the other hand, saline stress increased spermine and cadaverine levels, and the in vivo copper-containing amine oxidase activity in the elongation zone of hypocotyls. The last effect was negatively modulated by the addition of the copper-containing amine oxidase inhibitor N,N'-diaminoguanidine. In turn, plants treated with the inhibitor showed a significant reduction of reactive oxygen species in the elongation zone, even in the saline situation. In addition, plants grown in cadaverine-amended culture medium showed increased hypocotyl length either in saline or control conditions and this effect was also abolished by N,N'-diaminoguanidine. Taken together, our results suggest that the activity of the copper-containing amine oxidase may be partially contributing to hypocotyl growth under saline stress, through the production of hydrogen peroxide by polyamine catabolism and reinforce the importance of polyamine catabolism and hydrogen peroxide production in the induction of salt tolerance in plants.
已经研究了含铜胺氧化酶介导的多胺分解代谢与暴露于 NaCl 的大豆下胚轴伸长之间的可能关系。盐处理降低了所有下胚轴生长参数的值。在体外，含铜胺氧化酶的活性比多胺氧化酶高 77 倍。这种酶偏爱尸胺而不是腐胺，即使在盐条件下也具有活性。另一方面，盐胁迫增加了亚精胺和尸胺的水平，并增加了下胚轴伸长区的体内含铜胺氧化酶活性。最后一种作用受到含铜胺氧化酶抑制剂 N,N'-二氨基胍的添加的负调节。反过来，用抑制剂处理的植物在伸长区表现出活性氧的显著减少，即使在盐胁迫情况下也是如此。此外，在添加尸胺的培养基中生长的植物，无论是在盐胁迫条件下还是在对照条件下，下胚轴长度都增加，而 N,N'-二氨基胍则消除了这种效应。总之，我们的结果表明，含铜胺氧化酶的活性可能通过多胺分解代谢产生过氧化氢，部分促进盐胁迫下下胚轴的生长，并强调多胺分解代谢和过氧化氢产生在诱导植物耐盐性中的重要性。
