scholarly journals Underground gibberellin activity: differential gibberellin response in tomato shoots and roots

2020 ◽  
Vol 229 (3) ◽  
pp. 1196-1200
Author(s):  
Uria Ramon ◽  
David Weiss ◽  
Natanella Illouz‐Eliaz
Keyword(s):  
Gibberellin Activity

EPTC Effects on Corn (Zea Mays) Growth and Endogenous Gibberellins.

Weed Science ◽  
1979 ◽  
Vol 27 (1) ◽  
pp. 122-127 ◽  
Author(s):  
W. W. Donald ◽  
R. S. Fawcett ◽  
R. G. Harvey
Keyword(s):  
Zea Mays ◽  
Leaf Growth ◽  
Stem Growth ◽  
Endogenous Gibberellin ◽  
Hybrid Corn ◽  
Treated Soil ◽  
Abnormal Distribution ◽  
Gibberellin Activity ◽  
Corn Plants ◽  
Root Treatment

Hydroponic treatment with EPTC (S-ethyl dipropylthiocarbamate) inhibited leaf growth and stimulated stem growth of hybrid corn (Zea maysL. ‘Wisconsin 473′). Root treatment with GA3(gibberellic acid) prevented leaf stunting from EPTC. Most abnormalities in foliar display and height from treatment with 50 μM EPTC were prevented by increasing GA3levels from 0.5 μM to 10 μM over a week. The effect of EPTC on endogenous gibberellin activity was measured by bioassay of shoot extracts. EPTC (6.7 kg/ha) reduced the levels of total endogenous gibberellin-like substances in eight-day-old seedlings grown in treated soil. Under the environmental condtions of the experiment, this corresponded to the first discernable signs of injury. In addition EPTC induced an abnormal distribution of endogenous gibberellins in the shoots of older corn plants. Leaves of two-week-old EPTC-treated plants contained less gibberellin activity than the leaves of controls. Stems of herbicide-treated plants contained the same levels of gibberellin-like substances as the controls.

Developmental Stages and Gibberellin Activity in Ovules of Abscission-affected Fruits of Malus domestica Borkh

1988 ◽  
Vol 132 (1) ◽  
pp. 10-15 ◽  
Author(s):  
S. Avanzi ◽  
P. Vernieri ◽  
N. Ceccarelli ◽  
A.M. Tagliasacchi ◽  
L.M.C. Forino ◽  
...  
Keyword(s):  
Malus Domestica ◽  
Developmental Stages ◽  
Malus Domestica Borkh ◽  
Gibberellin Activity

Changes in the Endogenous Level of Auxins and Gibberellin-Like Substances in the Shoot Apices of Nitrogen-Deficient Tomato Plants (Lycopersicon esculentum Mill)

1974 ◽  
Vol 22 (3) ◽  
pp. 429 ◽  
Author(s):  
V Rajagopal ◽  
IM Rao
Keyword(s):  
Growth Inhibitor ◽  
Shoot Apices ◽  
Tomato Plants ◽  
Nitrogen Levels ◽  
Inhibitor Level ◽  
Gibberellin Activity ◽  
Three Stages ◽  
Last Stage ◽  
Growth Promoting ◽  
Normal Supply

Tomato plants were grown at three nitrogen levels: normal supply (control), moderate deficiency (one-eighth the normal supply – 1/8N) and acute deficiency (-N). Plant heights were reduced by 51.4 and 75.7 % respectively at 40 days under the latter two treatments compared with control plants. The biological activity of growth-promoting and growth-inhibiting substances was determined in the shoot apices of the three sets of plants at three stages: 20, 30 and 40 days after sowing. In general, the endogenous auxin was higher in control than in 1/8N and - N plants. The growth inhibitor level was higher in -N plants than in control and 118N plants. Gibberellin activity was less in nitrogen- starved plants than in controls. - N plants exhibited not only loss of gibberellins but an accumulation of inhibitors at the last stage. A negative correlation between growth promotors (auxins and gibberellins) and growth inhibitors was evident. The interaction between auxins, gibberellins and inhibitors is discussed.

scholarly journals Gibberellin and the Growth of Peach and Apricot Fruits

1968 ◽  
Vol 21 (2) ◽  
pp. 209 ◽  
Author(s):  
D I Jackson
Keyword(s):  
Cell Division ◽  
Growth Phase ◽  
Cell Expansion ◽  
Full Bloom ◽  
Gibberellin Level ◽  
Gibberellin Activity

Levels of gibberellin in purified extracts from developing peach fruits were compared with rates of cell division and cell expansion in the fruit tissues. No gibberellin was found in the ovary before full bloom. Immediately after full bloom gibberellin activity was found in the seed, and later in the mesocarp and endocarp as well. Gibberellin concentration was closely correlated with the rate of cell expansion in each tissue, but not with cell division. Until the final growth phase, when activity was found only in the mesocarp, the highest gibberellin level was always found in the seed.

scholarly journals Mutations in the tomato gibberellin receptors suppresses xylem proliferation and reduces water loss under water-deficit conditions

2020 ◽  
Author(s):  
Natanella Illouz-Eliaz ◽  
Idan Nissan ◽  
Ido Nir ◽  
Uria Ramon ◽  
Hagai Shohat ◽  
...  
Keyword(s):  
Water Deficit ◽  
Water Loss ◽  
Water Status ◽  
Stomatal Closure ◽  
Normal Growth ◽  
Hydraulic Conductance ◽  
Leaf Water Content ◽  
Whole Plant ◽  
Drought Conditions ◽  
Gibberellin Activity

AbstractLow gibberellin (GA) activity in tomato (Solanum lycopersicum) inhibits leaf expansion and reduces stomatal conductance. These lead to lower transpiration and improve water status under transient drought conditions. Tomato has three GIBBERELLIN-INSENSITIVE DWARF1 (GID1) GA receptors with overlapping activities and high redundancy. We have tested whether mutation in a single GID1 reduces transpiration without affecting growth and productivity. CRISPR-Cas9 gid1 mutants were able to maintain higher leaf water content under water-deficit conditions. Moreover, while gid1a exhibited normal growth, it showed reduced whole plant transpiration and better recovery from dehydration. Mutation in GID1a inhibited xylem vessels proliferation that led to lower hydraulic conductance. In stronger GA mutants, we also found reduced xylem vessel expansion. These results suggest that low GA activity affects transpiration by multiple mechanisms; it reduces leaf area, promotes stomatal closure and reduces xylem proliferation and expansion and as a result, xylem hydraulic conductance. We further examined if gid1a perform better than the control M82 in the field. Under these conditions, the high redundancy of GID1s was lost and gid1a plants were semi-dwarf, but their productivity was not affected. Although gid1a did not perform better under drought conditions in the field, it exhibited higher harvest index.HighlightThe loss of the tomato gibberellin receptors GID1s reduced xylem proliferation and xylem hydraulic conductance. These contribute to the effect of low gibberellin activity on water loss under water-deficit condition.

Seedling Development in Peach, Prunus persica (L.) Batsch. II. Effects of Plant Growth Regulators and Their Possible Role

1977 ◽  
Vol 4 (3) ◽  
pp. 359 ◽  
Author(s):  
RP Zigas ◽  
BG Coombe
Keyword(s):  
Abscisic Acid ◽  
Water Stress ◽  
Plant Growth ◽  
Plant Growth Regulators ◽  
Growth Regulators ◽  
Prunus Persica ◽  
Stem Elongation ◽  
Seedling Development ◽  
Inhibitor Activity ◽  
Gibberellin Activity

Treatment of peach embryos from partially stratified seeds with abscisic acid (ABA) inhibited germination and promoted the production of leaf lesions, responses which are typical of testa presence. A period of water stress during germination also promoted lesion production. Neither testas nor ABA stimulated lesions on seedlings from 25°C-stratified seed, but mixtures of ABA and GA*3 were synergistic in promoting lesions; at the same time ABA and GA3 had opposite effects on germination and stem elongation, and mixtures had intermediate effects. Evidence was obtained for effects attributable to a balance between GA and ABA. Other inhibitors and promotors had no effect on lesions. The results from excision and substitution experiments permit an explanation of the effects of stratification in terms of three events: (a) a decrease in inhibitor activity in the testa; (b) an increase in gibberellin activity in the epicotyl; and (c) diffusion of inhibitor to the epicotyl via the radicle when the seed is returned to warm conditions.

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