1-MCP prevents ultrastructural changes in the organelles of Dendrobium petals that are induced by exogenous ethylene.

Ethylene is a plant hormone that causes flower senescence. Dendrobium flowers are sensitive to ethylene and ethylene can induce premature senescence depending on the cultivar and the ethylene concentration. Dendrobium 'Lucky Duan' is one of the most sensitive cultivars to ethylene exposure.

Vesicles between plasma membrane and cell wall prior to visible senescence of Iris and Dendrobium flowers.

Cut Iris flowers (Iris x hollandica, cv. Blue Magic) show visible senescence about two days after full opening. Epidermal cells of the outer tepals collapse due to programmed cell death (PCD).

Macroautophagy and microautophagy in relation to vacuole formation in mesophyll cells of Dendrobium tepals.

Prior to flower opening, mesophyll cells at the vascular bundles of Dendrobium tepals showed a large increase in vacuolar volume, partially at the expense of the cytoplasm. Electron micrographs indicated that this increase in vacuolar volume was mainly due to vacuole fusion. Macroautophagous structures typical of plant cells were observed.

Amorphous areas in the cytoplasm of Dendrobium tepal cells: production through organelle degradation and destruction through macroautophagy?

In Dendrobium flowers some tepal mesophyll cells showed cytoplasmic areas devoid of large organelles. Such amorphous areas comprised up to about 40% of the cross-section of a cell. The areas were not bound by a membrane.

Do plastids in Dendrobium cv. Lucky Duan petals function similar to autophagosomes and autolysosomes?

In animal cells a double-membrane-bound structure, the autophagosome, encloses a portion of the cytoplasm. The encapsulated material becomes digested after fusion of the autophagosome with a vesicle containing lytic enzymes. The autophagosome is then termed autolysosome.

Do mitochondria in Dendrobium petal mesophyll cells form vacuole-like vesicles?

Using transmission electron microscopy, we investigated the ultrastructure of mitochondria in petal mesophyll cells of the orchid Dendrobium cv. Lucky Duan, from the time of floral opening to visible petal senescence. Cells close to the vascular bundle contained many mitochondria, some of which showed internal degeneration.