Callose Deposition and Cytopathology of Capsicum annuum Infected with TSWV

PurposeTo study the defense response of Tomato spotted wilt orthotospovirus (TSWV) to Capsicum annuum, and to reveal the regularity of pathological changes.

MethodsThe systemic leaves of C. annuum were collected at 1, 3, 7, 14 and 21 days after friction inoculation by TSWV. The deposition of callose and the ultrastructural changes were observed by aniline blue staining and transmission electron microscopy.

ResultsAfter inoculated TSWV on C. annuum, TSWV virus particles were observed in the cells, and callose deposition was observed in stomata, sieve tube and cell wall of C. annuum systemic leaves. Meanwhile, the ultrastructure of the cells was damaged, chloroplast structure was damaged, deformation and disintegration occurred, and the cell died seriously.

ConclusionAfter TSWV infection, C. annuum initiated callose deposition to prevent further virus invasion; but at the same time, it can also cause cell lesions, leading to plant chlorosis, deformity and necrosis.