• Journal of Plant Biology
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• v.28 no.4
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• pp.261-270
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• 1985

The portion of Cuscuta japonica haustorium which lies external to the host tissues, the upper haustorium, was investigated at the light- and electron-microscopic levels. The haustorium lightly contacted with the host was formed by the expansion of the epidermis and cortex of the stem at the contact side, and to have a group of meristematic cells within the haustorial cortex. When such a haustorium was closely contacted with the host, the meristematic region transformed into a primordial structure of the endophyte (endophyte primordium, EP) which may penetrate into the host tissues. EP consisted of the three kinds of cell group: dividing cells at the adaxial or proximal side; large, elongate cells (idioblasts) at the middle portion,; compressed cells at the abaxial or basal side. the idioblasts were characterized by the presence of large nucleus, dense cytoplasm, several small vacuoles, and abundant cell organelles including the multilamellar structures and cytosegresomes, and thus suggested to have a high metabolic activity. The features of the EP were discussed in relation to the possibility of the penetrating into host tissues.

• Journal of Plant Biology
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• v.21 no.1_4
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• pp.39-44
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• 1978

Acid phosphatase activities were analyzed in $\mu\textrm{g}$ tissue samples from an angiosperm parasite (Cuscuta cephalanthi) and its host plant (Hedera helix) by a fluorometric microtechnique. The apex and the coiling portion of the parasite axis exhibited greater enzyme activies than other portions of the hypha. Acid phosphatase activity in the haustorium was 2-3 times that in the hyphal axis. The vascular bundles of the normal host exhibited the greatest enzyme activity. The acid phosphatase activity in the host infected by the parasite decreased to the activity level of the haustorium.

• Journal of Plant Biotechnology
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• v.35 no.1
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• pp.47-53
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• 2008

Effects of growth regulators and culture conditions on seed germination, haustorium development, and callus formation of Korean mistletoe (Viscum album var. coloratum (Kom.) Ohwi) were described. Histological examination showed that seed of V. album contained one or two zygotic embryos with rod shape, and actively dividing cells were mainly distributed in radicle region rather than cotyledon of zygotic embryo. The most significant factor for seed germination and haustorium development of V. album was the requirement of the light. Various growth regulators examined in this study failed to substitute the effect of the light on seed germination. The frequency of callus formation was highest at 27.3% when flower buds were cultured onto B5 medium containing $0.1\;mgl^{-1}$ IAA. Explants from other organs were recalcitrant in forming calluses. Culture conditions described in this study could be applied for production of useful metabolites and multiplication of V. album in future.

• Applied Microscopy
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• v.15 no.2
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• pp.1-9
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• 1985

The portion of Cuscuta japonica haustorium which lies internal to the host tissues, the endophyte, was examined at the ultrastructural level. The endophyte consisted of mainly small parenchymatous cells and large, slightly elongate cells at the tip. The tip cells were characterized by the presence of large and lobed nucleus, several small vacuoles, dense cytoplasm, abundant rough endoplasmic reticulum, dictyosomes, and mitochondria, and thus suggested to have a high metabolic activity. The shape, arrangement, and cytological characteristics of the parenchymatous and tip cells consisting the endophyte were very similar to those of the dividing cells and idioblasts, respectively, which appeared in the endophyte primordium of the upper haustorium. The tip cells with the thickened-apical wall were observed to grow intrusively through the host cell walls and to engulf the remnants of the degenerated host cells. In the former case intrusive growing cell was regarded to develop into the filamentous cell, the hypha. Plasmodesmata through the cell wall were not observed between host and parasite cells. Some host cells that in contact with the penetrating tip cells of the endophyte, showed the degenerating features such as a loss of cytoplasm, a beaded fashion of small vesicles, and deformation of chloroplasts.

• Proceedings of the Botanical Society of Korea Conference
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• 1999.04a
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• pp.6-6
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• 1999

• Journal of Korean Society of Forest Science
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• v.99 no.4
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• pp.618-624
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• 2010

This study was conducted to establish the in vitro seed germination of Loranthus tanakae. A factorial experiment evaluated the effects of seed storage duration (0, 8, 16 weeks), media (MS, SH, White, WPM), presence of viscin, GA3, gelling agent and concentrations. Seed germinated after one week culture in in vitro condition and produced radicles. In vitro seed germination was optimal when the seeds removed viscin placed on SH medium (69%) and the addition of 0.35% gelrite (75%) in the same medium. As seed storage duration was expanded to 8 or 16 weeks, in vitro seed germination rate was reduced rapidly. Holdfasts were also produced at the side of radicles. The important factors to produce holdfast and haustorium was kind of media as an optimal condition in White medium without any supplements to be shown 98% and 8% respectively. Process of in vitro germination of Loranthus tanakae was followed to radicle elongation, holdfast development and then haustorium formation sequencially.

• Korean Journal Plant Pathology
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• v.10 no.2
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• pp.83-91
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• 1994

Stem tissues of tomato plants (cv. Kwanyang) inoculated with Phytophthora capsici were examined by light and electron microscopy to compare early cytological differences between comaptible and incompatible interactions of tomatoes with the fungus. Twenty four hours after inoculation, the compatible isolate S 197 colonized severely the epidermis, cortex, and xylem vessels of stem tissue, whereas only few fungal cells colonized the stem tissues inoculated with the incompatible isolate CBS 178.26. Fragmented plasma membrane, distorted chloroplast, degraded cell wall, remnants of host cytoplasm were early ultrastructural features of the damaged host cell observed both in the compatible and incompatible interaction, a number of vesicles were distributed in the space between fungal cell walls and plasma membrane. The degradation of host cell walls by P. capsici was more pronounced in the compatible than the incompatible interactions. The incompatible interactions of tomato cells with P. capsici were characterized by formation of host cell wall apposition in the cortical parenchyma cells, indicating that the apposition of electron-dense material from the host cell walls may function as a plant defense reaction to the fungus. The fungal cells encased by wall appositions had abnormal cytoplasm and separated plasma membranes. The haustorium which formed from the fungal hyphae did not further penetrate through the host wall apposition and cytoplasmic aggregation, especially in the incompatible reactions. In contrast, the haustorium of the compatible isolate S 197 was not encased by wall appositions.

• Journal of the Korean Wood Science and Technology
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• v.40 no.4
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• pp.268-275
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• 2012

This study was carried out to understand the anatomical characteristics of Korean mistletoe (Viscum album var. coloratum) and host tree of Mongolian oak (Quercus mongolica) by the aid of light and scanning electron microscopy. The branch diameter of host tree at the parasitic part by mistletoe is larger than that of non-parasitic part. In the mistletoe, phloem consists of bast fiber and parenchyma cell and xylem is composed of fiber, ray and axial parenchyma cell, and vascular tracheid. The volume of ray parenchyma cell is higher than common wood species and is heterocellular made up of procumbent, upright, and square cells in the mistletoe. In the vascular tracheid of mistletoe, coarse spiral thickenings and bordered pit are present. Due to the insertion of the mistletoe haustorium, some deformed vessels but no tylosis are observed in the mistletoe. The shapes of mistletoe haustorium are sharp, and the destruction of the host tree cells due to the insertion of the mistletoe haustorium are not identified.

• Korean Journal of Medicinal Crop Science
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• v.11 no.2
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• pp.122-126
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• 2003

This study was conducted to investigate plant growth characteristics and anatomical studies of Korean mistel (Viscum album var. coloratum (Kom.) Ohwi). Parasite position was upper part that has a plenty of sunshine area 5 to 10m apart from the ground, regardless host tree. Stem developed two branch stems from the each basal stem, leaf was grown from the end stems as opposite. Fruit has a light yellow color and berry size was 7 to 8 mm long diameter and it contains seed. Floral bud differentiation initiated with forming rounded dome and arch-shaped floral apex at the beginning stage, and produced heart-shaped sepal following the differentiation of leaf primordia. Floral bud formation processed centeral part first and following bilateral sides were developed in order. Leaf was thick and stoma and guard cell were observed from the two or three inner layers from the epidermis. Mistletoe penetrated cork cambium of host plant and was growing by rooting on xylem. Korean mistel connected to host plant through parasitic organ, haustorium structurally and physiologically.

• The Plant Pathology Journal
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• v.31 no.3
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• pp.299-304
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• 2015

Interaction of the the rust fungus Puccinia miscanthi with the biofuel plant Miscanthus sinensis during the teliospore phase was investigated by light and electron microscopy. P. miscanthi telia were oval-shaped and present on both the adaxial and abaxial leaf surfaces. Teliospores were brown, one-septate (two-celled), and had pedicels attached to one end. Transmission electron microscopy revealed numerous electron-translucent lipid globules in the cytoplasm of teliospores. Extensive cell wall dissolution around hyphae was not observed in the host tissues beneath the telia. Hyphae were found between mesophyll cells in the leaf tissues as well as in host cells. Intracellular hyphae, possibly haustoria, possessed electron-dense fungal cell walls encased by an electron-transparent fibrillar extrahaustorial sheath that had an electron-dense extrahaustorial membrane. The infected host cells appeared to maintain their membrane-bound structures such as nuclei and chloroplasts. These results suggest that the rust fungus maintains its biotrophic phase with most mesophyll cells of M. sinensis. Such a nutritional mode would permit the rust fungus to obtain food reserves for transient growth in the course of host alteration.