perennial plants like mugwort. Herbicides that inhibit amino acid formation in plants and those which mimic indole-3-acetic acid are usually systemic in nature, and therefore, multiple herbicides in these classes of chemistry often have some activity on
Rebecca M. Koepke-Hill, Gregory R. Armel, William E. Klingeman, Mark A. Halcomb, Jose J. Vargas, and Phillip C. Flanagan
Shuguang Wang, Yongpeng Ma, Chengbin Wan, Chungyun Hse, Todd F. Shupe, Yujun Wang, and Changming Wang
D ). Fig. 1. Localization of indole-3-acetic acid (IAA) at the top of Fargesia yunnanensis shoots. ( A ) Immunohistochemical localization at the shoot tip, showing the strong IAA signal in the apical meristem (black arrow), sheath primordia (white
Ningguang Dong, Qingmin Wang, Junpei Zhang, and Dong Pei
The relationship between auxin and adventitious root formation has been studied for many years. Indole-3-acetic acid plays a central role in adventitious rooting and was the first plant hormone used to stimulate the rooting of cuttings ( Cooper
Ying Gao, Hao Liu, Ningguang Dong, and Dong Pei
) differentiation stages; SAM = shoot apical meristem; sq = squama; VB = vascular bundle; lp = leaf primordial; ( A–F ) bar = 100 μm, ( G ) bar = 200 μm. Indole-3-acetic acid immunohistochemical localization. Excised samples were immediately fixed in a 2% (w
Hameed J. Aljuburi
An experiment was conducted at the United Arab Emirates Univ., in Al-Ain, to study the effect of saline water on the growth characteristics of date palm (Phoenix dactylifera L.) seedings cultivar Lulu-salt alone or a combination of NaCl and indole acetic acid (IAA) or IAA alone were tested with different levels. Then the plant growth characteristics were measured. Hormone did not antagonize the salt effect on shoot length of date palm seedlings. Application of 24 mg·L–1 salt alone or in combination with hormone and 12 mg·L–1 in combination with 0.2 mg·L–1 IAA significantly increased the root: shoot ratio over the control. Irrigation date palm seedlings with saline water alone or in combination with IAA for 80 days resulted in a significant increase in dry matter (percentage) of leaves with salt symptoms, whereas the number of leaves per seedling were reduced over the control. The results also showed that the irrigation of seedlings with 0.15 mg·L–1 IAA in combination with 24 or 12 mg·L–1 salt alleviated adverse effect of salt by increasing or reducing significantly root length or leaves with salt symptoms percentage over using 24 or 12 mg·L–1 salt alone.
Joseph E. Beeler, Gregory R. Armel, James T. Brosnan, Jose J. Vargas, William E. Klingeman, Rebecca M. Koepke-Hill, Gary E. Bates, Dean A. Kopsell, and Phillip C. Flanagan
·ha −1 acid equivalent) or Myrothecium verucaria alone controlled trumpetcreeper 45% and 30%, respectively ( Boyette et al., 2008 ). Bradley et al. (2003) reported that reduced rates of two mimics of indole-3-acetic acid, dicamba (280 g·ha −1 ) and 2
Jerry D. Cohen
gratefully acknowledged. For discussions that resulted in this work and for their advice on the manuscript, the author thanks Janet P. Slovin and James R. Dunlap. Indole-3-acetyl-1- 0 -β-D-glucose and 4-Cl-IAA were from D. Keglevic and V. Magnus, respectively
Debra Reiss-Bubenheim, Charles Winget Dr., and Robert S. Bandurski Dr.
The gravity-sensing mechanism in plants end transduction of the gravity stimulus to re-orientating plant growth has not been ascertained. By removing the everpresent influence of the 1 g terrestrial environment on plant growth and development, information maybe obtained about the gravity detection mechanism in plants. The Space Life sciences Payloads Office at NASA-ARC processed the secondary Payloads flight experiment “Growth Hormone Concentration and Distribution in Plants” (GHCD). The experiment occupied two middeck lockers in the crew compartment onboard the space shuttle Atlantis (STS-34) in October 1989. The payload's Principal Investigator was Dr. S. Bandurski, Professor of Botany at Michigan State University. dr. Bandurski's experiment was designed to investigate concentration, distribution, and turnover rates of indole-3 acetic acid (IAA) in dark-grown corn seedlings exposed to the microgravity environment. The flight data may provide valuable information for long-term crop production in space as well as terrestrial agriculture. This poster will present the flight payload processing procedures necessary to successfully conduct a space shuttle flight experiment.
Rongcai Yuan, Ulrich Hartmond, and Walter J. Kender
Endogenous concentrations of IAA and ABA in the peel, pulp, seed, and abscission zone of mature `Valencia' oranges [Citrus sinesis (L.) Osbeck] were determined by high-performance liquid chromatography and enzyme-linked immunosorbent assay from early November 1998 to mid-June 1999. Ethylene production of mature `Valencia' oranges during the same period was determined by gas chromatography. IAA concentrations in the pulp and seed were three to five times lower than those in the peel over the 7-month observation period. IAA concentration in the abscission zone and peel was high from late April to mid-May, the period of less responsiveness to abscission chemicals. ABA concentration in the pulp was low over the entire observation period. ABA concentration in the abscission zone and peel was low during the less responsive period. Ethylene production was always low except for a slight increase during late December and early February. The IAA to ABA ratio was high in the fruit abscission zone during the less responsive period. Fruit detachment force of CMN-pyrazole-treated fruit was positively correlated with the ratio of endogenous IAA to ABA or endogenous IAA, but negatively to endogenous ABA in the fruit abscission zone. These data suggest the balance between IAA and ABA in the fruit abscission zone may be an important factor in determining sensitivity and thereby the response of mature `Valencia' orange fruit to abscission chemicals. Chemical names used: abscisic acid (ABA); indole-3-acetic acid (IAA); 5-chloro-3-methyl-4-nitro-1H-pyrazole (CMN-pyrazole).
Shiow Y. Wang, Miklos Faust, and Michael J. Line
The effect of Indole-3-acetic acid (IAA) on apical dominance in apple (Malus domestica Borkh.) buds was examined by studying changes In proton density (free water) and membrane lipid composition in lateral buds. Decapitation induced budbreak and enhanced lateral bud growth. IAA replaced apical control of lateral bud paradormancy. Maximal inhibition was obtained when IAA was applied immediately after the apical bud was removed. Delaying this application weakens the effect of IAA. An increase in proton density in lateral buds was observable 2 days after decapitation, whereas the change in membrane lipid composition occurred 4 days later. Decapitating the terminal bud induced an increase in membrane galacto- and phospholipids. and the ratio of unsaturated to corresponding saturated fatty acids. Decapitation also induced a decrease in the ratio of free sterols to phospholipids in lateral buds. Application of IAA to the terminal end of decapitated shoots inhibited the increase of proton density and prevented changes in the membrane lipid composition of lateral buds.