Akademik Veri Yönetim Sistemi
Agrica, cilt.13, ss.12-20, 2024 (Hakemli Dergi)
Phytoplasmas are one of the most aggressive
phloem-limited pathogens that are obligate parasites of
plants transmitted by sap-feeding insects which also
serve as their hosts. Phytoplasma infection leads to
massive changes on plant morphology associated with a
severely impaired ultrastructure of the host cells.
However, the detailed aspects of the intricate
modiÞcations that phytoplasmas cause on their host
plants remain unclear. In this study, we conducted a
morphological comparison between healthy and
phytoplasma-infected daffodil (Narcissus tazetta) leaves
and utilized light microscopy, epißuorescence
microscopy and transmission electron microscopy
(TEM) to comprehensively examine how phytoplasma
infection modiÞes the ultrastructure of phloem cell
walls, sieve tubes and plasmodesmata. We also describe
a method based on the use of Syto 9/PI dual staining,
adaptable for preliminary detection studies of
phytoplasmas. TEM examinations visually conÞrmed
the presence of phytoplasmas within the sieve tubes and
identiÞed changes in plant cells due to infection. In the
phytoplasma infected daffodil leaves, pleomorphic
bodies (PBs) were observed within the sieve elements.
Additionally, an elevation in callose collars at the ends of
the pore-plasmodesma units of the sieve elements,
conformational changes in phloem proteins, and cell
wall thickening were noted in the phytoplasma infected
leaves compared to healthy ones. This study offers fresh
perspectives on as a structural point of view for
enhancing our comprehension of intracellular obligate
cell wall-less prokaryotes and host phloem structures,
and will aid in understanding of their interactions