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.
Debra Reiss-Bubenheim, Charles Winget Dr., and Robert S. Bandurski Dr.
Peter L. Sholberg, Paul Randall, and Cheryl R. Hampson
Acetic acid (AA) fumigation of rootstocks and dormant shoots was explored as a method of eliminating plant pathogens from propagation material. Dormant shoots were tested in early winter to determine the rate of AA vapor that they could tolerate before being damaged. Apricot (Prunus armeniaca), apple (Malus ×domestica), and peach (Prunus persica) shoots collected from a single site in Dec. 1999 tolerated 30, 12, or 6 mg·L–1 AA, respectively. Vineland 3 (V3) and Malling-Merton 106 (MM.106) rootstock liners fumigated with 1 mg·L–1 AA were adequately surface-sterilized although the effect on growth was not recorded. A similar experiment with Malling 9 (M9) rootstocks showed that 12 mg·L–1 AA would eliminate most surface microorganisims from roots although it delayed shoot growth when the trees were planted. The higher 15 mg·L–1 rate delayed tree growth and appeared to kill some trees. The 12 mg·L–1 rate prevented growth of Erwinia amylovora and Pseudomonas syringae pv. syringae bacteria on shoots even when an enrichment technique was used to detect them. Finally, when 96 `Jonagold' apple shoots known to be infected by Podosphaera leucotricha were fumigated with AA in 2001, none developed powdery mildew, although 99% of the control shoots did. These promising results suggest that further research should be done toward adapting AA fumigation for use by commercial nurseries.
Wesley R. Autio, James Krupa, Jon M. Clements, and Duane W. Greene
In 2004, at full bloom, 3-year-old `Cameo'/G.16, `Gala'/M.9 NA-KBT337, `Gala'/G.16, and `Redmax'/B.9 apple trees were treated with naphthalene acetic acid (NAA, 1.5% in latex paint) in a 7.5-cm band completely around the central leader at the base of 2-year-old wood. NAA treatment reduced 2004 extension growth of the central leader by 14% and total shoot growth above the treatment area by 32%. `Cameo'/G.16 trees also were sprayed with prohexadione-Ca (250 ppm with surfactant and water conditioner) at full bloom, and additional trees were sprayed with ethephon (500 ppm with surfactant) 1 week after full bloom. These spray treatments were made only to the stems and foliage from the base of the central leader's 2-year-old wood to the top of the canopy. Ethephon reduced total shoot growth in 2004 by 26%, and prohexadione-Ca reduced it by 63%. Prohexadione-Ca also reduced fruit set of `Cameo' in 2004. Scoring (single knife cut completely around the circumference of the trunk) at the base of the 2-year-old wood in the `Cameo' trees resulted in a 23% reduction in leader growth and a 22% in totals shoot growth in the upper canopy in 2004. In 2005 at full bloom, 4-year-old `Golden Delicous'/B.9 trees were treated with NAA similarly to trees in 2004, except treatment at the base of 2-year-old wood was compared to treatment at the base of 1-year-old wood. Treating the base of 1-year-old wood reduced growth to a greater degree than comparable treatment at the base of 2-year-old wood. For the 1- and 2-year-old-wood treatments, the number of laterals produced from the 1-year-old wood was reduced 42% and 17%, and total shoot growth from 1-year-old wood was reduced by 49% and 31%, respectively.
Y.D. Park, A.A. Boe, and M.K. Ehlenfeldt
Leaf disks of potato cv. Kennebec and ND 860-2 (North Dakota potato breeding clone) were cultured on Murashige Skoog (MS) medium supplemented with 6 levels of indole acetic acid (IAA) and 7 levels of zeatin riboside (ZR). Shoots were induced at various combinations of hormone levels. The medium containing 3.5 mg/l IAA and 4.0 mg/l ZR produced the most shoots. Rooted plantlets were grown in the greenhouse. The growth of regenerated plants obtained from the MS medium supplemented with 7.0 mg/l IAA and 3.0 mg/l ZR was significantly greater than those grown from nodal explants. In ND 8602, a leaf chimera with chlorophyll deficient (light yellow) sectors was found in plants regenerated from leaf disks (grown on MS medium supplemented with 3.5 mg/l IAA and 3.0 mg/l ZR) but not in plants grown from nodal explants. Phenotypic variability was also observed for tuber number, size and weight.
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.
Ibrahim I. Tahir, Sven-Erik Svensson, and David Hansson
( Wooldridge and Harris, 1991 ). To avoid these negative impacts, mechanical tillage should be replaced with new floor management systems that are productive under the constraints of organic fruit growing ( Delate et al., 2008 ). Acetic acid (vinegar) has been
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).
Allen V. Barker and Randall G. Prostak
( Liu and Christians, 1994 ; 1996 ). Attention has been given to the organic acids, acetic acid (vinegar) ( Johnson et al., 2004 ; Radhakrishnan et al., 2003 ; Webber and Shrefler, 2007 ; Young, 2004 ), and citric acid ( Chase et al., 2004 ). These
M.M. Jenderek and A.J. Olney
The ability of Hibiscus syriacus explants to produce regenerable callus was investigated. Fragments of cotyledons, hypocotyl, and roots were cultured on MS media supplemented with two different auxins (2,4-D and NAA, both 0.3 mg/L) and three different cytokinin (BA, 2iP and kinetin, all 0.1 mg/L). Plants were regenerated on McCown media with three different cytokinins at two different concentrations (0.1 and 1.0 mg/L). The biggest volume of callus was produced on medium containing 2,4-D/2iP (2,821 mm3/explant). The smallest mass of callus was induced on medium with NAA/kinetin (120 mm3/explant). On BA-supplemented media, the auxin type had no significant influence on the amount of callus produced. The highest number of shoots and leaves was produced on callus induced on NAA/BA supplemented media and regenerated on medium with 0.1 mg/L BA (4.2 shoots and 20 leaves/explant). Callus cultured on medium with 1.0 mg/L of BA produced significantly less shoots (2.4 shoots/explant). The lowest number of shoots was observed on callus originating from NAA/kinetin and NAA/2iP callus media and grown on medium with kinetin or 2ip (both 1.0 mg/L). The highest number of roots was produced by cultures originating from NAA/BA callus medium grown on the BA regeneration medium, irrespective of the cytokinin level. The longest shoots were observed on medium supplemented with 1.0 mg/L BA (18 mm). In this study, the best plant regeneration results were obtained for callus initiated on NAA/BA supplemented medium and regenerated on medium with 0.1 mg/L BA, however, the highest production of callus was observed on medium with 2,4-D/2iP.
Shiow Y. Wang, Miklos Faust, and Michael J. Line
The effect of IAA on apical dominance in apple buds was examined in relation to 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 buds and maintained paradormancy. Maximal inhibition was obtained when IAA was applied immediately after the apical bud was removed; delaying application reduced the effect of IAA. An increase in proton density in lateral buds was observed 2 days after decapitation, whereas the change in membrane lipid composition occurred 4 days later. Removing the terminal bud increased membrane galacto- and phospholipids and the ratio of unsaturated to corresponding saturated fatty acids. Decapitation also decreased the ratio of free sterols to phospholipids in lateral buds. Applying thidiazuron to lateral buds of decapitated shoots enhanced these effects, whereas applying IAA to the terminal end of decapitated shoots inhibited the increase of proton density and prevented changes in membrane lipid composition in lateral buds. These results suggest that change in water movement alters membrane lipid composition and then induces lateral bud growth. IAA, presumably produced by the terminal bud, restricts the movement of water to lateral buds and inhibits their growth in apple.