Some Aspects of the Control of Root Growth and Georeaction: The Involvement of Indoleacetic Acid and Abscisic Acid

Paul-Emile Pilet; Malcolm C. Elliott

doi:10.1104/pp.67.5.1047

Natürliche Hemmstoffe von Keimung und Wachstum, I Ausarbeitung eines quantitativen Biotests und Anwendung auf Extrakte aus Spelzen von Avena sativa L. / Natural Inhibitors of Germination and Growth, I. Development of a Quantitative Biotest and Application upon Extracts from Husks of Avena sativa L.

Zeitschrift für Naturforschung C ◽

10.1515/znc-1982-0911 ◽

1982 ◽

Vol 37 (9) ◽

pp. 793-801 ◽

Cited By ~ 4

Author(s):

Rudolf Karl ◽

Wolfhart Rüdiger

Keyword(s):

Abscisic Acid ◽

Root Growth ◽

Organic Acids ◽

Avena Sativa ◽

Inhibitory Activity ◽

Lepidium Sativum ◽

Carbonic Acids ◽

Germination And Growth ◽

Natural Inhibitors ◽

Lepidium Sativum L

Extracts from oat husks inhibit germination of a variety of seeds including Avena sativa L., Sorghum spec., Phalleris spec., Raphanus spec., Amaranthus caudatus, Lepidium sativum L. A quantitative assay for this inhibition was developed on the basis of percentage of root growth of Avena in the presence of extracted material compared with root growth of water controls. Fractionation of the extracts revealed that about half of the total inhibitory activity was found in the fraction of free organic acids. The inhibition was not due to known inhibitors. Abscisic acid. was not found in this extract. Phenole carbonic acids were determined in the extract. Their concentration was too low to significantly contribute to the observed inhibitory activity.

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Inhibition of cambial activity in Abies balsamea by internal water stress: role of abscisic acid

Canadian Journal of Botany ◽

10.1139/b75-333 ◽

1975 ◽

Vol 53 (24) ◽

pp. 3041-3050 ◽

Cited By ~ 35

Author(s):

C. H. A. Little

Keyword(s):

Abscisic Acid ◽

Water Stress ◽

Indoleacetic Acid ◽

Stomatal Closure ◽

Abies Balsamea ◽

Cambial Activity ◽

Inhibitory Effect ◽

Internal Water ◽

Endogenous Aba

In experiments with attached and detached shoots of balsam fir, Abies balsamea L., synthetic (±)abscisic acid (ABA) (1) reduced photosynthesis and transpiration by inducing stomatal closure, (2) inhibited indoleacetic acid (IAA) - induced cambial activity in photosynthesizing and non-photosynthesizing shoots, and (3) inhibited the basipetal movement of [14C]IAA. Neither gibberellic acid nor kinetin counteracted the inhibitory effect of (±)ABA on IAA-induced cambial activity. In addition it was demonstrated that increasing the internal water stress increased the level of endogenous ABA in the phloem–cambial region of bark peelings and decreased the basipetal movement of [14C]IAA through branch sections. On the basis of these findings it is proposed that internal water stress inhibits cambial activity, partly through increasing the level of ABA; the ABA acts to decrease the provision of carbohydrates and auxin that are required for cambial growth.

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Salt tolerance and regulation of gas exchange and hormonal homeostasis by auxin-priming in wheat

Pesquisa Agropecuária Brasileira ◽

10.1590/s0100-204x2013000900004 ◽

2013 ◽

Vol 48 (9) ◽

pp. 1210-1219 ◽

Cited By ~ 5

Author(s):

Muhammad Iqbal ◽

Muhammad Ashraf

Keyword(s):

Abscisic Acid ◽

Gas Exchange ◽

Acid Concentration ◽

Spring Wheat ◽

Indoleacetic Acid ◽

Co2 Assimilation ◽

Assimilation Rate ◽

Co2 Assimilation Rate ◽

Net Co2 Assimilation Rate ◽

Net Co2 Assimilation

The objective of this work was to assess the regulatory effects of auxin-priming on gas exchange and hormonal homeostasis in spring wheat subjected to saline conditions. Seeds of MH-97 (salt-intolerant) and Inqlab-91 (salt-tolerant) cultivars were subjected to 11 priming treatments (three hormones x three concentrations + two controls) and evaluated under saline (15 dS m-1) and nonsaline (2.84 dS m-1) conditions. The priming treatments consisted of: 5.71, 8.56, and 11.42 × 10-4 mol L-1 indoleacetic acid; 4.92, 7.38, and 9.84 × 10-4 mol L-1 indolebutyric acid; 4.89, 7.34, and 9.79 × 10-4 mol L-1 tryptophan; and a control with hydroprimed seeds. A negative control with nonprimed seeds was also evaluated. All priming agents diminished the effects of salinity on endogenous abscisic acid concentration in the salt-intolerant cultivar. Grain yield was positively correlated with net CO2 assimilation rate and endogenous indoleacetic acid concentration, and it was negatively correlated with abscisic acid and free polyamine concentrations. In general, the priming treatment with tryptophan at 4.89 × 10-4 mol L-1 was the most effective in minimizing yield losses and reductions in net CO2 assimilation rate, under salt stress conditions. Hormonal homeostasis increases net CO2 assimilation rate and confers tolerance to salinity on spring wheat.

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