Ultrastructure of crystalline inclusions in the thylakoids of dodder(cuscuta japonica) plastids

Abstract

The plastids from seedlings of the parasitic angiosperm Cuscuta japonica were ultrastructurally investigated. In shoot subapical cells from 3-d-old seedlings grown in the dark, the etioplasts contained prolamellar bodies and amorphous and dense inclusions. In the shoot subapical cells obtained from 6-d-old seedlings grown under light conditions for the last 3 d, the underdeveloped chloroplasts contained phytoferritin within the stroma as well as amorphous and dense inclusions that were limited by the thylakoid membranes. In the developing chloroplasts, electron-dense materials were detected within the transversely sectioned thylakoid lumens. This dense material presented two different images, depending upon the sectional plane. When transversely prepared, the materials appeared as somewhat thick, linear structures, whereas longitudinally sectioned thylakoids revealed very large crystalline inclusions. In the developed chloroplasts, the amounts of electron-dense material or crystalline inclusions were remarkably reduced in the thylakoid lumens, which were electron-translucent. Far fewer crystalline inclusions were observed in the developed chloroplasts of seedlings than in the developing chloroplasts. These results suggest that the crystalline inclusions may be temporarily reserved within the thylakoid lumens of chloroplasts in the C. japonica seedlings.

Structure and Development of the Endophyte in the Parasitic Angiosperm Cuscuta japonica

“…The tips of light-grown Cuscuta japonica seedlings have chloroplasts with thylakoids that are well organized into grana (Lee 2007a), which are converted from etioplasts with starch grains, prolamellar bodies, and crystalline structures (Lee 2007b). After the tips of the parasite seedlings contact the host, the upper haustorium, lies external to the host, develops via three main successive stages-the haustorial initials, the meristem, the endophyte primordium (EP, a hostinvading tissue)-from the middle layers of the cortex of the parasite stem (Lee 2007c).…”

Anatomy and ultrastructure of epidermal cells in the haustorium of a parasitic flowering plant,Cuscuta japonica, during attachment to the host

“…I b). After contact, subsequent changes to the epidermal cells could be described based on three main developmental stages of the upper haustorium: the haustorial initials, the meristem, and the endophyte primordium (a host-penetrating tissue) in the middle layer of the cortex in the parasite stem (Lee, 2007b). During the first stage of contact between parasite and host, haustorial initials with a dense cytoplasm and prominent nuclei appeared in the middle layer of cortical cells from the parasite stem ( Fig.…”