Using various photostationary state light sources to obtain reproducible phytochrome conversion of from 5 to 88% P(FR), assayed by 2 wavelength in vivo spectrophotometry, relationships between initial percent P(FR) and elongation of apical Avena coleoptile segments over the succeeding 20 hours in darkness were studied. With material grown in total darkness, all P(FR) levels promote elongation, ...

A large and diverse group of organic compounds is reported to "regulate" plant growth. Many of the determinations of growth regulation, however, do not measure the accelerating effects on growth but the inhibition of growth or toxicity effects. Such evidence does not suffice to identify the substances as growth regulators which may either accelerate or inhibit the growth process depending upon ...

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...

Two experiments were conducted to study the effects of water deficit stress on the germination, emergence and seedling growth of sorghum [Sorghum bicolor (L.) Moench] using Completely Randomised Block Design in four replications. Five sorghum cultivars (Jigurti, Gambella 1107, Meko, 76 T1 #23 and P9403) were evaluated under three water deficit stress treatments (0, -0.20 and -0.85 MPa) using PE...

Beside indoleacetic acid (IAA), 3 auxins were found by chromatographic resolution of acidic fractions of Avena and Zea coleoptile tips. One of these auxins, designated P, occurred at levels of activity approaching those of IAA. The other 2 auxins, termed F and M, occurred at lower levels of activity. When the auxins of the excised coleoptile tips were isolated immediately after equilateral or u...

Objective: In order to Investigate effects of Gibberlic acid (GA3) and Sprimidin Poly Amine on Germination of three Cultivars of Wheat under Salinity Stress. Methods: The experiment was conducted as factorial based on completely randomized design with four replicates in Agronomy and plant breeding laboratory of Agricultural department of Islamic Azad University, Varamin-Pishva branch in spring ...

Aleurone layers of Hordeum vulgare, cv. ;Himalaya' took up [(14)C]-abscisic acid (ABA) when incubated for various times. Radioactivity accumulated with time in a low speed, DNA-containing pellet accounting for 1.6 to 2.3% of the radioactivity recovered in subcellular fractions at 18 hours. Thin layer chromatography of ethanolic or methanolic extracts of the cytosol, which contained greater than...