Growth Profile of Crown Gall Cells of Tobacco in Suspension Culture

The auxin level in the cell mass and culture medium was determined by means of the <em>Avena</em> straight caleoptile test in various periods of the suspension culture cycle of the sunflower crown-gall tumour. The investigations were performed in the course of the zero passage (PO) and first one (Pl), differing in their time of duration of maximum growth and its intensity. In both passages the intra- and extra-cellular auxin levels reach values of the same order. At the beginning of the maximal growth phase the activity corresponding to IAA in the cells prevails over that of the other auxin-like compounds. This disproportion diminishes with further development of the culture, and with the beginning of the stationary phase the cellular IAA level is lower than that of the remaining auxin-like compounds. The short phase of maximal growth (PO) occurs with an auxin level decreasing in the cell mass and increasing in the medium, and towards the end of the cycle these levels become equal. During the long phase of maximal growth (Pl) the total amount of auxins in the cells increases and is 2-3 times higher than in the medium, whereas IAA in the cells remains at a constant level. These results suggest that the participation of IAA in the intracellular pool of auxin-like substances is decisive for the mitotic activity of the cells and maintenance of growth in the culture.

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Changes in the content of phenolic compounds and IAA-oxidase activity during the growth of tobacco crown gall suspension culture

Biologia Plantarum ◽

10.1007/bf02897338 ◽

1990 ◽

Vol 32 (1) ◽

pp. 19-27 ◽

Cited By ~ 1

Author(s):

Zofia Chirek

Keyword(s):

Phenolic Compounds ◽

Suspension Culture ◽

Crown Gall ◽

Oxidase Activity ◽

Iaa Oxidase

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Dynamics of indole-3-acetic acid oxidase activity in suspension culture of sunflower crown-gall

Acta Societatis Botanicorum Poloniae ◽

10.5586/asbp.1984.008 ◽

2014 ◽

Vol 53 (1) ◽

pp. 67-75 ◽

Cited By ~ 1

Author(s):

Zofia Chirek

Keyword(s):

Suspension Culture ◽

Crown Gall ◽

Oxidase Activity ◽

Middle Part ◽

Acid Oxidase ◽

Iaa Oxidase ◽

Auxin Level ◽

Feedback Type ◽

Indole 3 Acetic Acid ◽

Intensive Growth

IAA oxidase activity was determined in several growth phases of a suspension culture of sunflower crown-gall. During the short phase of intensive growth (zero passage - PO) a negative correlation was noted between enzymatic activity and the rate of growth. IAA oxidase activity increased to a certain level is not a factor limiting cell division. For protraction of the phase of intensive growth (first passage - P1), however, a decrease in the activity of this enzyme seems indispensable. IAA oxidase activity in the tested culture is under the control of inhibitors present in the cells and medium. High enzyme inhibition was observed in PO cells during the phase, of intensive growth and in P1 at the beginning and in the middle part of this phase. These results suggest' that the -auxin level determined in earlier studies in sunflower crown-gall culture is controlled by the IAA oxidase set. During the long phase of intensive growth (P1) this control is of negative feedback type.

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