Departament de Producció Vegetal i Ciència Forestal, ETSEA, Universitat de Lleida, Av. Alcalde Rovira Roure 191, E-25198 Lleida, Spain.
Plant Physiol Biochem. 2010 Jul;48(7):553-9. doi: 10.1016/j.plaphy.2010.01.014. Epub 2010 Jan 28.
We investigated the effect of methyl jasmonate (MeJa) treatment on the expression of two genes in the rice polyamine biosynthesis pathway and on the polyamine content in wild type plants and transgenic rice plants expressing a Datura stramonium (Ds) Adc cDNA, the latter accumulating up to three-fold the normal level of putrescine. Exogenous MeJa transiently inhibited the expression of OsAdc1, OsSamdc and Spermidine synthase (OsSpds) genes in the polyamine biosynthesis pathway, probably through transcriptional repression. There was also a similar negative impact on the DsAdc transgene in transgenic plants, even though a constitutive promoter was used to drive transgene expression. The free putrescine content was reduced significantly in the leaves of both wild type and transgenic plants in response to MeJa, although the magnitude of the effect was greater in wild type plants. We discuss our findings with respect to the previously proposed threshold model of polyamine metabolism in plants subjected to abiotic stress.
我们研究了茉莉酸甲酯（MeJa）处理对水稻多胺生物合成途径中两个基因的表达以及多胺含量的影响，后者在表达颠茄（Ds）Adc cDNA 的转基因水稻植物中积累了正常水平三倍的腐胺。外源 MeJa 瞬时抑制了多胺生物合成途径中 OsAdc1、OsSamdc 和 spermidine synthase（OsSpds）基因的表达，可能通过转录抑制。即使使用组成型启动子驱动转基因表达，对转基因植物中的 DsAdc 转基因也有类似的负面影响。茉莉酸甲酯处理后，野生型和转基因植物的叶片中游离腐胺含量显著降低，尽管野生型植物的影响幅度更大。我们根据先前提出的植物非生物胁迫下多胺代谢的阈值模型讨论了我们的发现。
