Effects of Microtubule Polymerization Inhibitor on the Hypersensitive Response of Wheat Induced by the Non-Host Pathogen Sphaerotheca fuliginea

The plant cytoskeleton is a highly dynamic and versatile intracellular scaffold composed of microtubules and microfilaments, serving a multiplicity of functions in plant cells. To reveal the relationship between the cytoskeleton in wheat (Triticum aestivum L.) cv. Suwon 11 attacked by the non-host pathogen Sphaerotheca fuliginea and the initiation of the hypersensitive response, the microtubule inhibitor oryzalin was injected into the wheat leaves immediately prior to inoculation. The incidence of hypersensitive cell death was significantly lower than that in water-treated control. In addition, the occurrence of hypersensitive cell death was also delayed and S. fuliginea was able to penetrate and form haustoria in epidermal tissues of wheat. All the results above indicated that hypersensitive cell death was associated with depolymerisation of microtubules, suggesting that microtubules might play an important role in the expression of non-host resistance of wheat.