Changes in peroxidase activity, auxin level and ethylene production during root formation by poplar shoots raised in vitro

1993 ◽  
Vol 13 (3) ◽  
pp. 263-268 ◽  
Author(s):  
J. F. Hausman
Keyword(s):  
Peroxidase Activity ◽  
Ethylene Production ◽  
Root Formation ◽  
Auxin Level ◽  
Poplar Shoots

scholarly journals Rhizogenesis in in vitro shoot cultures of passion fruit (Passiflora edulis f. flavicarpa Deg.) is affected by ethylene precursor and by inhibitors

2001 ◽  
Vol 7 (1) ◽  
Author(s):  
W. M. Marota ◽  
W. C. Otoni ◽  
M. Carnelossi ◽  
E. Silva ◽  
A. A. Azevedo ◽  
...  
Keyword(s):  
Ethylene Production ◽  
Time Course ◽  
Root Formation ◽  
Callus Formation ◽  
Passion Fruit ◽  
Shoot Cultures ◽  
Ethylene Inhibitors ◽  
Beneficial Effects ◽  
Ethylene Precursor

The effects of the ethylene precursor ACC and two inhibitors, AgNO3 and AVG, on root formation were tested in in vitro shoots of passion fruit (Passiflora Midis f.flavicalpa Deg.). The organogenic response was assessed on the basis of percentage of shoot-forming. roots, root number and length. The time course of ethylene production was also monitored. ACC inhibited root formation by delaying root emergence and increasine, callus formation at the basis of the shoots. In addition, ACC caused a marked increase in ethylene production, coupled to leaf chlorosis and senescence with lower rooting frequencies, number and length of roots. IAA supplementation increased ethylene production. Both ethylene inhibitors, AgNO3 and AVG, at appropriate concentrations reduced callus formation at the basis of shoots. AVG increased the number of roots per shoot, but drastically reduced length of differentiated roots. Regarding to leaf pigments, ACC promoted a marked reduction on carotenoids and total chlorophyll, whereas AVG and AgNO3 delayed explant senescence and pigments degradation, not differing from IAA supplemented and non-supplemented control treatments. The results confirm previous reports on the beneficial effects of ethylene inhibitors on in vitro rooting and suggest its reliability to be used as an alternative approach to evaluate sensitivity of Passiflora species to ethylene.  

Xylem ethylene, phenol-oxidizing enzymes, and nitrogen and heartwood formation in walnut and cherry

1978 ◽  
Vol 56 (6) ◽  
pp. 626-634 ◽  
Author(s):  
Neil D. Nelson
Keyword(s):  
Total Nitrogen ◽  
Peroxidase Activity ◽  
Ethylene Production ◽  
Growing Season ◽  
Cambial Activity ◽  
Boundary Region ◽  
Heartwood Formation ◽  
Dormant Period

In black walnut sapwood, ethylene production, in vitro, near the heartwood boundary peaks early in the dormant period and is low while the cambium is active. In black cherry, ethylene production in the heartwood–sapwood transition zone peaks during the middle to the late growing season and is greater than in the middle and the outer sapwood during early dormancy. In walnut, in vitro peroxidase (EC 1.11.1.7) activity near the heartwood boundary peaks during the late growing season to the early dormant period and is greater than in the adjacent sapwood regions. In both species, ethylene production correlates with peroxidase activity. In vivo tyrosinase (EC 1.10.3.1) and peroxidase activities are relatively high near the heartwood boundary during dormancy. Laccase (EC 1.10.3.2) is absent from the heartwood boundary region. Total nitrogen levels reach a minimum during the dormant period. General phenological biochemical trends suggest that in both species dormancy is a time of major heartwood formation. Heartwood formation in walnut apparently is minimal when cambial activity is greatest. Walnut phenotypes that differ in heartwood-formation class, a measure related to sapwood–heartwood ratio, also differ in sapwood peroxidase activity. In cherry sapwood, ethylene production and total nitrogen are related to heartwood formation class.

Ethylene production by ectomycorrhizal fungi, Fusarium oxysporum f. sp. pini, and by aseptically synthesized ectomycorrhizae and Fusarium-infected Douglas-fir roots

1980 ◽  
Vol 26 (11) ◽  
pp. 1340-1347 ◽  
Author(s):  
J. H. Graham ◽  
R. G. Linderman
Keyword(s):  
Fusarium Oxysporum ◽  
Ectomycorrhizal Fungi ◽  
Ethylene Production ◽  
Mycorrhizal Fungi ◽  
Root Formation ◽  
Pathogenic Fungus ◽  
Douglas Fir ◽  
Cenococcum Geophilum ◽  
Host Interactions

The ectomycorrhizal fungi Cenococcum geophilum, Hebeloma crustuliniforme, and Laccaria laccata produced ethylene in vitro in modified Melin–Norkrans liquid medium only if amended with 2.5–10 mM methionine; Pisolilhus tinctorius failed to produce ethylene unless the cultures were renewed with fresh methionine-amended medium before ethylene assay. An additional 19 ectomycorrhizal fungi, plus five isolates of Fusarium oxysporum f. sp. pini, all produced ethylene in renewed and (or) nonrenewed media. Although the rates varied, ethylene production by many ectomycorrhizal fungi equaled that of Fusarium.Culture filtrates of H, crustuliniforme and L. laccata also evolved ethylene that was apparently of nonenzymatic origin.Ethylene was produced by aseptically grown Douglas-fir seedlings inoculated with C. geophilum, H. crustuliniforme, and L. laccata and appearance of ethylene coincided with the formation of mycorrhizae; production by P. tinctorius inoculated seedlings was inconsistent. Lateral root formation of Douglas-fir was stimulated by inoculation with C. geophilum, H. crustuliniforme, and L. laccata but was inhibited by P. tinctorius. Fusarium-inoculated seedlings produced more ethylene sooner than seedlings inoculated with mycorrhizal fungi. The disparity in the levels of ethylene associated with ectomycorrhiza formation compared with Fusarium infection suggests a possible differential role for ethylene in symbiotic and pathogenic fungus–host interactions.

THE ROLE OF CYTOKININS AND ETHYLENE INHIBITORS ON LENTICEL HYPERTROPHY GENERATION AND ETHYLENE PRODUCTION IN IN VITRO CULTURES OF POPULUS EUPHRATICA OLIVIER

1995 ◽  
Vol 43 (4) ◽  
pp. 339-345 ◽  
Author(s):  
M.D. Lledó ◽  
M.B. Crespo ◽  
J.B. Amo-Marco
Keyword(s):  
Ethylene Production ◽  
Populus Euphratica ◽  
In Vitro Cultures ◽  
Nodal Segments ◽  
Ethylene Inhibitors ◽  
Se Spain ◽  
Ethylene Formation ◽  
Free Media

Populus euphratica Olivier is native to the Irano—Turanian areas (Middle East). Elche (Alicante province, SE Spain) is known to be its only European location. Nodal segments from root shoots were established in vitro in a Murashige and Skoog medium supplemented with several cytokinins. Ethylene inhibitors AgNO3 and CoCl2 were used in combination with kinetin. Hormone-free media supplemented with sucrose (20–60 mg 1−1) was also tested. Ethylene was measured by gas chromatography, and both the percentage of sprouting shoots and lenticel hypertrophy in cultures were recorded. Ethylene production was higher in cultures supplemented with cytokinins (especially with meta-topolin), with high sprouting percentages, and lenticel hypertrophy. In cultures supplemented with 6-benzylaminopurine or 6-(γ,γ,-dimethylallylamino)-purine, ethylene production was lower and explants looked unhealthy. Ethylene formation was inhibited in cultures supplemented with AgNO3 (1 mg 1−1), which also decreased percentage of sprouting buds and lenticel hypertrophy.

In Vitro Root Formation in Anacardium Occidentale Microshoots

2001 ◽  
Vol 44 (2) ◽  
pp. 175-179 ◽  
Author(s):  
B. Boggetti ◽  
J. Jasik ◽  
S.H. Mantell
Keyword(s):  
Root Formation ◽  
Anacardium Occidentale

Auxin-polyamine interaction in the control of the rooting inductive phase of poplar shoots in vitro

Plant Science ◽  
1995 ◽  
Vol 110 (1) ◽  
pp. 63-71 ◽  
Author(s):  
J.F. Hausman ◽  
C. Kevers ◽  
T. Gaspar
Keyword(s):  
Inductive Phase ◽  
Poplar Shoots
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