Gárriz Andrés, Gonzalez María E, Marina María, Ruiz Oscar A, Pieckenstain Fernando L
Instituto de Investigaciones Biotecnológicas, Universidad Nacional de General San Martín-Consejo Nacional de Investigaciones Científicas y Técnicas, Casilla de Correo 164, (7130) Chascomús, Buenos Aires, Argentina.
Mycol Res. 2008 Mar;112(Pt 3):414-22. doi: 10.1016/j.mycres.2007.10.016. Epub 2007 Nov 12.
A study on polyamine metabolism and the consequences of polyamine biosynthesis inhibition on the development of Sclerotinia sclerotiorum sclerotia was conducted. Concentrations of the triamine spermidine and the tetramine spermine, as well as ornithine decarboxylase and S-adenosyl-methionine decarboxylase activities, decreased during sclerotia maturation. In turn, the concentration of the diamine putrescine was reduced at early stages of sclerotial development but it increased later on. This increment was not related to de novo biosynthesis, as demonstrated by the continuous decrease in ornithine decarboxylase activity. Alternatively, it could be explained by the release of putrescine from the conjugated polyamine pool. Alpha-difluoro-methylornithine and cyclohexylamine, which inhibit putrescine and spermidine biosynthesis, respectively, decreased mycelial growth, but did not reduce the number of sclerotia produced in vitro even though they disrupted polyamine metabolism during sclerotial development. It can be concluded that sclerotial development is less dependent on polyamine biosynthesis than mycelial growth, and that the increase of free putrescine is a typical feature of sclerotial development. The relationship between polyamine metabolism and sclerotial development, as well as the potential of polyamine biosynthesis inhibition as a strategy for the control of plant diseases caused by sclerotial fungi are discussed.
开展了一项关于多胺代谢以及多胺生物合成抑制对核盘菌菌核发育影响的研究。在菌核成熟过程中，三胺亚精胺和四胺精胺的浓度以及鸟氨酸脱羧酶和S-腺苷甲硫氨酸脱羧酶的活性均下降。相反，二胺腐胺的浓度在菌核发育早期降低，但随后升高。这种增加与从头生物合成无关，鸟氨酸脱羧酶活性的持续下降证明了这一点。另外，这可以通过结合多胺库中腐胺的释放来解释。分别抑制腐胺和亚精胺生物合成的α-二氟甲基鸟氨酸和环己胺降低了菌丝体生长，但即使它们在菌核发育过程中破坏了多胺代谢，也没有减少体外产生的菌核数量。可以得出结论，菌核发育比菌丝体生长对多胺生物合成的依赖性更小，并且游离腐胺的增加是菌核发育的一个典型特征。本文还讨论了多胺代谢与菌核发育之间的关系，以及抑制多胺生物合成作为控制由菌核真菌引起的植物病害策略的潜力。
