Ultrastructure of cytopathological responses in Solanum tuberosum cv. Spounta infected with necrotic strain of potato virus Y

Abstract

Ultrastructural responses of plant cell organelles in leaf tissues of potato cv. Spounta towards potato virus Y (PVY-necrotic and ordinary strains) infection were investigated using an electron microscope. Numerous cytopathological alterations in cell wall, middle lamella, nucleus, chloroplast, mitochondria, endoplasmic reticulum and peroxisomes have been observed compared to healthy tissues. Splitting, destroying, joining to neighboring protoplasts and necrosis in cell wall were observed. Cell nucleus was changed to lobe-like shape; damage in envelope and enlargement of pore complexes were observed. Mitochondria were increased in number, elongated and destroyed. Many changes in chloroplasts such as deformation, reduction in size and number, damage of envelope and grana thylakoids were observed. Virus particles and cytoplasmic inclusions were observed in ultra-thin sections. To our knowledge, obtained results showed that only peroxisomes could be responsible organelles for induction of necrotic symptoms, because they were increased in number and frequently existed only in plant cells infected with PVY-necrotic strain.