AUXIN TRANSPORT AND STEM GROWTH IN TULIPS: THE ROLE OF EPIDERMIS, CORTEX AND PITH

Scirpus americanus Pers., a major dune slack plant in coastal sand dune ecosystems, differs in height along transects ranging between the lowest and highest elevational areas of slacks located along the coast of Delaware, U.S.A. Using reciprocal transplant and common garden experiments, results suggest that environmental factors rather than hereditary traits are more important in accounting for the differences in plant morphology expressed in the field. Dune slack plants are exposed to stresses of waterlogging and sand accretion in their natural environment. In controlled greenhouse experiments waterlogging was shown to inhibit stem growth and cause an increase in aerenchymatous tissue, whereas periodic sand deposition caused an increase in the plant height of Scirpus.

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Role of basipetal auxin transport and lateral auxin movement in rooting and growth of etiolated lupin hypocotyls

Physiologia Plantarum ◽

10.1111/j.1399-3054.2004.00323.x ◽

2004 ◽

Vol 121 (2) ◽

pp. 294-304 ◽

Cited By ~ 17

Author(s):

Juana Ines Lopez Nicolas ◽

Manuel Acosta ◽

Jose Sanchez-Bravo

Keyword(s):

Auxin Transport ◽

Basipetal Auxin Transport

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The role of polar auxin transport through pedicels of Prunus avium L. in relation to fruit development and retention

Journal of Experimental Botany ◽

10.1093/jxb/erh208 ◽

2004 ◽

Vol 55 (405) ◽

pp. 2099-2109 ◽

Cited By ~ 38

Author(s):

M. A. Else

Keyword(s):

Fruit Development ◽

Auxin Transport ◽

Prunus Avium ◽

Polar Auxin Transport ◽

Prunus Avium L

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Both Induction and Morphogenesis of Cyst Nematode Feeding Cells Are Mediated by Auxin

Molecular Plant-Microbe Interactions ◽

10.1094/mpmi.2000.13.10.1121 ◽

2000 ◽

Vol 13 (10) ◽

pp. 1121-1129 ◽

Cited By ~ 123

Author(s):

Aska Goverse ◽

Hein Overmars ◽

Jan Engelbertink ◽

Arjen Schots ◽

Jaap Bakker ◽

...

Keyword(s):

Root Formation ◽

Auxin Transport ◽

Infection Site ◽

Cell Morphogenesis ◽

Cell Wall Degrading Enzymes ◽

Cyst Nematodes ◽

Site Specific ◽

Auxin Concentration ◽

Local Accumulation

Various lines of evidence show that local changes in the auxin concentration are involved in the initiation and directional expansion of syncytia induced by cyst nematodes. Analysis of nematode infections on auxin-insensitive tomato and Arabidopsis mutants revealed various phenotypes ranging from complete inhibition of syncytium development to a decrease in hypertrophy and lateral root formation at the infection site. Specific activation of an auxin-responsive promoter confirmed the role of auxin and pointed at a local accumulation of auxin in developing syncytia. Disturbance of auxin gradients by inhibiting polar auxin transport with N-(1-naphthyl)phtalamic acid (NPA) resulted in abnormal feeding cells, which were characterized by extreme galling, massive disordered cell divisions in the cortex, and absence of radial expansion of the syncytium initial toward the vascular bundle. The role of auxin gradients in guiding feeding cell morphogenesis and the cross-talk between auxin and ethylene resulting in a local activation of cell wall degrading enzymes are discussed.

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Stem growth responses of declining mature Abiesamabilis trees after tephra deposition from Mount St. Helens

Canadian Journal of Forest Research ◽

10.1139/x95-162 ◽

1995 ◽

Vol 25 (9) ◽

pp. 1493-1502 ◽

Cited By ~ 5

Author(s):

Gerardo Segura ◽

Thomas M. Hinckley ◽

Chadwick D. Oliver

Keyword(s):

Radial Growth ◽

Stem Growth ◽

Silver Fir ◽

Growth Responses ◽

Stem Analysis ◽

Cross Sectional ◽

Breast Height ◽

Per Se ◽

Mount St Helens

Stem analysis of mature Abiesamabilis (Dougl.) Forbes (Pacific silver fir) trees was used to analyze patterns of radial growth in areas of southwestern Washington where this species is experiencing a severe crown decline associated with heavy tephra deposition from the 1980 eruption of Mount St. Helens. Reductions in stem growth after 1980 appeared to be related to the severity of crown damage. The largest reductions in cross-sectional area increment exceeded 50% and extended along most of the stem. An increase in stem growth in the upper crown was common among declining trees. This zone coincided with a portion of the crown that has experienced vigorous and rapid growth since 1980. The role of this recovery zone on subsequent tree recovery is discussed. Decline or recovery of trees appeared independent of crown class per se. Reductions in radial growth of declining trees tended to be more pronounced at breast height, suggesting that estimations of whole-stem growth based on breast height measurements would overestimate growth losses.

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Ethylene Does Not Promote Adventitious Root Initiation on Apple Microcuttings

Journal of the American Society for Horticultural Science ◽

10.21273/jashs.121.5.880 ◽

1996 ◽

Vol 121 (5) ◽

pp. 880-885 ◽

Cited By ~ 7

Author(s):

James F. Harbage ◽

Dennis P. Stimart

Keyword(s):

Carboxylic Acid ◽

Auxin Transport ◽

Adventitious Rooting ◽

Polar Auxin Transport ◽

Root Initiation ◽

Ethylene Evolution ◽

Basal Section ◽

Naphthylphthalamic Acid ◽

Transport Inhibitors

We investigated the role of ethylene on adventitious rooting of `Gala' (easy-to-root) and `Triple Red Delicious' (difficult-to-root) apple (Malus domestica Borkh.) microcuttings. Root count increased significantly as IBA level increased, with highest root counts on `Gala'. Ethylene evolution increased significantly with IBA level without significant differences between cultivars. Basal section removal of microcuttings in the area of root origin reduced root count without changing ethylene evolution. Ethylene treatment of proliferated shoots before microcutting excision failed to enhance rooting. IBA-induced ethylene evolution was eliminated nearly by AVG, but root count remained IBA dependent. ACC reversed IBA plus AVG rooting inhibition, but ACC alone failed to influence root count. Polar auxin transport inhibitors NPA and TIBA stimulated ethylene evolution without increasing root count. Adventitious rooting of apple microcuttings was not associated with ethylene. Chemical names used: 1-H-indole-3-butyric acid (IBA); aminoethoxyvinylglycine (AVG); 1-aminocyclopropane-1-carboxylic acid (ACC); 2,3,5-triiodobenzoic acid (TIBA); N-1-naphthylphthalamic acid (NPA).

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