Ultrastructural Changes during Swelling and Contraction of Mitochondria from Cold-hardened and Non-hardened Winter Wheat 1
AUTOR(ES)
Pomeroy, M. Keith
RESUMO
Mitochondria isolated from both 2 and 24 C grown winter wheat (Triticum aestivum L.) undergo spontaneous swelling in isomolar KCI solutions, but only 24 C mitochondria exhibit a substrate-induced contraction response. Electron microscopic examination revealed that 24 C mitochondria have more clearly defined cristae, less matrix material, and are generally more electron-dense than 2 C mitochondria. During swelling, the matrix material of both 2 and 24 C mitochondria expands and the mitochondria become less electron-dense. After partial swelling, 24 C mitochondria contract upon addition of succinate, and regain structural characteristics similar to those of untreated mitochondria. In contrast, mitochondria from 2 C seedlings continue to swell after addition of substrate, and many of the mitochondria become irregular in shape and lose much of their matrix material. A comparison of results obtained from absorbancy measurements, electron microscopy, and a Coulter Counter indicate that swelling and contraction involve changes both in over-all volume, and internal structural characteristics of mitochondria from 2 and 24 C grown seedlings. Electron microscopic examination of shoot cells showed that mitochondria in 24 C grown seedlings possessed more recognizable cristae and greater internal organization than mitochondria in 2 C seedlings.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=542375Documentos Relacionados
- Swelling and Contraction of Mitochondria from Cold-hardened and Nonhardened Wheat and Rye Seedlings 1
- Leucine Transport in Cells Isolated from Cold-Hardened and Nonhardened Winter Rye 1
- Isolation and Freezing Tolerances of Mesophyll Cells from Cold-hardened and Nonhardened Winter Rye 1
- Spin-Probe Studies during Freezing of Cells Isolated from Cold-Hardened and Nonhardened Winter Rye 12: MOLECULAR MECHANISM OF MEMBRANE FREEZING INJURY
- A Comparative Spin-Label Study of Isolated Plasma Membranes and Plasma Membranes of Whole Cells and Protoplasts from Cold-Hardened and Nonhardened Winter Rye