During Space Shuttle STS-95 mission, we cultivated seedlings of rice (Oryza sativa L. cv. Koshihikari and cv. Tan-ginbozu) and Arabidopsis (Arabidopsis thaliana L. cv. Columbia and cv. etr1-1) for 68.5, 91.5, and 136 hr on board, and then analyzed changes in the nature of their cell walls, growth, and morphogenesis under microgravity conditions. In space, elongation growth of both rice coleopti...

The mechanism by which endogenous cessation of coleoptile elongation after emergence of the primary leaf is brought about was investigated in rye seedlings {Secale cereale L.) that were either grown in darkness or irradiated with continuous white light. In 3-d-old etiolated (growing) coleoptiles a turgor pressure of 0.59 MPa was measured. In 6-d-old coleoptiles, which had ceased to elongate, ce...

The ascomycete Fusarium graminearum is a destructive fungal pathogen of wheat (Triticum aestivum). To better understand how this pathogen proliferates within the host plant, we tracked pathogen growth inside wheat coleoptiles and then examined pathogen gene expression inside wheat coleoptiles at 16, 40, and 64 h after inoculation (HAI) using laser capture microdissection and microarray analysis...

The vertical growth responses of corn seedlings (Zea mays L. Mo17 x B73) were determined over an 8-hour period. When seedlings were decapitated 3 millimeters from the coleoptile's tip and supplied with indole-3-acetic acid (IAA) in 1.5% agar blocks, the response was dependent both on time and IAA concentration. The dose-response curves changed in shape and magnitude depending on the total time ...

Successful crop stand establishment is critical to realize high yield potential, which dependent on depth of seed placement access soil moisture. The coleoptile determines sowing by its length and ability emerge from depth. This study was conducted assess among three sets Great Plains winter small grain cereals—wheat (Triticum aestivum L.), barley (Hordeum vulgare L.) triticale (X triticosecale...

Oxygen deprivation limits the energy available for cellular processes and yet no comprehensive ATP budget has been reported for any plant species under O(2) deprivation, including Oryza sativa. Using 3-d-old coleoptiles of a cultivar of O. sativa tolerant to flooding at germination, (i) rates of ATP regeneration in coleoptiles grown under normoxia (aerated solution), hypoxia (3% O(2)), and anox...

Coleoptiles of barley (Hordeum vulgare) were positioned in a high gradient magnetic field (HGMF, dynamic factor gradient of H(2)/2 of 10(9)-10(10) Oe2 cm-1), generated by a ferromagnetic wedge in a uniform magnetic field and rotated on a 1 rpm clinostat. After 4 h 90% of coleoptiles had curved toward the HGMF. The cells affected by HGMF showed clear intracellular displacement of amyloplasts. Co...

Rice (Oryza sativa L.) seeds can germinate under anoxia and can show coleoptile elongation. The anoxic coleoptile is usually longer than aerobic coleoptiles. Although several hypotheses have been proposed to explain the ability of rice to elongate coleoptiles under anoxia, conclusive experimental evidence explaining this physiological trait is lacking. In order to investigate whether metabolic ...