Sarkissian (4) and Sarkissian and Srivastava (6) have pointed out a close correlation between complementation and heterosis effects with intact mitochondria isolated from wheat coleoptiles. In their experiments, mitochondria which were isolated from coleoptiles of heterozygous F1 plants show significantly higher values for 02 uptake, esterification of inorganic phosphate, and especially for res...

Irradiation of maize (Zea mays) roots and coleoptiles with visible light causes dark-reversible absorbance changes in these organs. There is an increase in absorbance near 440 nanometers and smaller increases below 410 nanometers and about 595 nanometers. Decreases in absorbance are observed at about 420 nanometers and minor ones at 537 and 575 nanometers. These responses are also observed in c...

The nonphotochemical reactions of phytochrome in the coleoptiles of dark-grown corn seedlings were studied at 3 temperatures: 14 degrees , 24 degrees , and 34 degrees . The data obtained show that the destruction of P(fr) is the only measurable reaction occurring; reversion of P(fr) to P(r) was not found. The Q(10)'s (2.7 and 3.5) and zero order kinetics found for the destruction reaction are c...

Avena coleoptiles did not elongate when incubated with tryptophan under sterile conditions. Indole, anthranilic acid, and tryptamine promoted elongation. Under the same conditions, the tissue converted tryptophan-(14)C to IAA-(14)C. More IAA-(14)C was produced from indole-(14)C than from tryptophan-(14)C; however, the free tryptophan content of the tissue was also greatly increased by the indol...

Cortical microtubules play an important role during morphogenesis by determining the direction of cellulose deposition. Although many triggers are known that can induce the reorientation of cortical plant microtubules, the reorientation mechanism has remained obscure. In our approach, we used gravitropic stimulation which is a strong trigger for microtubule reorientation in epidermal cells of m...