RESEARCH REPORTS TGC REPORT 52, 2002
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Table 2. Content of chlorophyll in leaves of tomato cv. Ventura exposed to
kanamycin.
Kanamycin (mg/l)
0
50
100
200
300
Control
34.0±0.4
33.8±0.0
22.2±0.2
13.5±0.6
10.1±0.1
Transgenic
51.1±0.3
42.0±0.4
34.6±0.6
29.8±0.3
28.0±0.1
To check the presence of the nptII expression, the developed leaves of both types
of plants were placed in kanamycin solution for seven day and differences between
them were evaluated thereafter as a diminishing of chlorophyll content (Table 2). The
integration of target iaglu gene in the tomato varieties was confirmed with PCR where
the amplification products of corresponding size were found in electrophoresis agarose
gels.
The growth and productivity can be supported by strengthening of the auxin status
expressed in enhanced IAA biosynthesis, IAA binding activity and IAA bounded
hydrolysis (Table 3). The content of free endogenous IAA in leaves of the transgenic
tomato was actually two-fold higher calculated by both fresh and dry weights.
The activity of UDPG-transferase, the enzyme coded by iaglu gene, was higher in
the cytosol from transgenic tomato plants. The activity of amidohydrolase in transgenic
tomato leaves as compared to the control was 14 times higher in Sephadex G-25
purified enzyme fractions. The substrate of this enzyme is the product of iaglu UDPG-
transferase.
It is likely that the balance between synthesis, conjugation, transport and hydrolysis
results in higher content and action of endogenous IAA in the transgenic tomato.
Table 3. The auxin status of control and transgenic tomato plants cv. Ventura
IAA
(nmol per g fr wt)
UDPG-transferase
(nmol/mg protein/hr)
Amidohydrolase
(nmol/mg protein/hr)
Control
64±4
139.9
278±0.2
Transgenic
112±29
286.3
3875±22
Varieties of transgenic tomato plants obtained by transformation grew faster than
the control ones, formed wider leaf blades, and had larger mass of shoots and stems
and more developed root system (Table 4). The transgenic plants were distinguished by
formation of a greater number of root primordia (more than 100) along the stem. They
started blooming earlier and formed greater amount of trusses and fruits, as well the red
fruits yield of the transgenic Ventura, Verlioka and Bumerang varieties were heavier
(Table 5) and harvest time occurred 7-10 days earlier.
28
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