BİTKİ PATOJENİ BAKTERİLERDE SALGI SİSTEMLERİ

Bitki patojeni gram negatif ve pozitif bakteriler bitkilerde hastalığa neden olan efektör proteinlere sahiptir. Bu proteinleri özel bakteriyel salgı sistemleri aracılığıyla bitki hücresi içerisine aktarırlar. Bitki patojeni bakteriler, hücre dışı protein salgılamasını kendi türüne özgü protein taşıma sistemi ile gerçekleştirir. Baz dizisi analizine göre bitki ve hayvan patojeni bakterilerin sahip oldukları hücre dışı salgı sistemleri büyük ölçüde benzerlik göstermektedir. Bu benzerliklere göre bakterilerdeki salgı sistemlerini Gram negatif bakterilerde; Tip I, Tip II, Tip III, Tip IV ve Tip V olmak üzere 5 grupta, Gram pozitif bakterilerde; Tip I, Tip II ve Tip V olmak üzere 3 grupta toplamak mümkündür. Gram negatif bitki patojeni bakterilerin çoğu Tip III Salgı sistemine sahiptir. Bu salgı sistemi hrp (aşırı duyarlılık ve hastalık oluşturma) genleri tarafından kodlanır ve bu genler, hassas bitkilerde hastalık oluşturma, dayanıklı bitkilerde ise aşırı duyarlılık için gereklidir SECRETION SYSTEMS IN PLANT PATHOGENIC BACTERIA Plant pathogenic gram-negative and positive bacteria that cause disease in plants have effector proteins. These proteins pass into the plant cell via special bacterial secretion systems. Plant pathogenic bacteria implement extracellular secretion by their own protein transport systems. The base sequence analyses have shown that extracellular secretion systems in plant and animal pathogenic bacteria are to a large extent similar. According to these similarities, secretion systems in gram negative bacteria can be classified into five groups: Type I, Type II, Type III, Type IV and Type V, whereas gram-positive bacteria have three groups: Type I, Type II and Type V. Most of plant pathogenic gram-negative bacteria have type III secretion system. This secretion system is encoded by hrp (for hypersensitive response and pathogenicity) genes, which are so named because they are required for bacteria in order to cause disease in susceptible plants and to elicit the hypersensitive response in resistant plants.

Keywords:

Bitki patojeni bakteriler salgı sistemleri, efektör proteinler,

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