Book of Abstracts - Geyseco

P - Posters
P01-115: QUANTITATIVE ANALYSIS OF ROOT RES-
PONSE TO MULTIPLE PHYSICAL CONSTRAINTS:
EFFECTS OF SOIL PORE STRUCTURE.
Valentine, T.A.* - Binnie, K. - Squire, G.R. - Hawes, C. - Hallett,
P.D. - Bengough, A.G.
SCRI
*Corresponding author, e-mail: tvalen@scri.ac.uk,
The impact of soil physical conditions on barley root elongation
and gene expression was assessed by repacking soil cores at 20
combinations of water content and dry bulk densities, and by
sampling intact soil (59 fields from across the east of Scotland).
Field cores were equilibrated to a matric potential of -20kPa. Repacked
core matric potential was measured using tensiometers
and a psycrometer. Root elongation was measured after destructive
harvest at 48h with maximum rates of 0.7mmh -1 and 0.63
mmh -1 in repacked and field cores respectively, compared with 1
mmh -1 in loosely packed sieved soil at optimum water content. In
50% of field cores root elongation was less than 50% of the maximum
growth rate achieved suggesting soil physical conditions
were limiting root elongation. 32% of variation in root growth
in repacked cores was accounted for by dry bulk density variation
(p=0.005), compared with 15% in field cores (p=0.001). In
contrast, large air-filled pore volume accounted for 61% of the
root growth variation in field cores (repacked ns.). This suggests
different root growth behaviour in soil cores with structural pores
verses uniform discontinuous pores. A complementary invitro
model system based on Arabidopsis, confocal microscopy and
the new image analysis techniques (PlantVis) has also shown
differences in meristem behaviour depending on pore spatial
structure. A high throughput method to assess gene expression of
barley roots in this system will also be presented.
P01-116: SALINITY EFFECTS ON PHOTOSYNTHESIS
PARAMETERS AND SECONDARY METABOLITE OF
TWO LETTUCE VARIETIES
Mahmoudi, H. 1 - Kaddour, R. 1 - Huang, J. 2 - Hannoufa, A. 2 -
Lachaâl, M. 1 - Ouerghi, Z. 1
1
Faculté des Sciences de Tunis
1
Agriculture and Agri-Food Canada, Southern Crop Protection
and Food Research Centre
Our study is interested to evaluate the effect of NaCl and Na 2
SO 4
treatments on photosynthesis parameters and secondary metabolite
of two lettuce varieties, Verte and Romaine. The experiments
were carried out under greenhouse conditions. Plants of lettuce
were acclimated for 7 days in hydroponic solution and supplemented
with or without 100 mM NaCl or 77 mM Na 2
SO 4
, for 12
days. Greater concentrations of chlorophyll were found in Verte
compared to Romaine, under both control and salinity treatment.
Net photosynthetic rate was similar in both varieties with and without
NaCl. This capacity was equally reduced for both varieties
with Na 2
SO 4
treatment. The stomatal conductance was strongly
reduced by salts, especially under Na 2
SO 4
treatment. In the absence
of salt treatment, leaves of both varieties had similar total
carotenoid levels. In presence of salts, ß-carotene, lutein, and total
carotenoids were significantly higher in Verte. The carotenoid
levels did not significantly change under either type of salt stress,
in Romaine. For polyphenol, both lettuce varieties contained
mainly phenolic acids with only a minor fraction of flavonoids, in
the absence of salt treatment. Under salt treatments, an increase
of total flavonoids was detected in Romaine compared to Verte.
The enhanced salt tolerance of Verte relative to Romaine is partly
reflected in the differential accumulation of carotenoid and phenolic
antioxidants. Verte accumulated higher levels of total carotenoids
and mainly individual carotenoids. These changes in
carotenoid contents of the two lettuce varieties cultivated under
salinity treatments did not correlate with the expression profiles
of PSY, PDS and ε-CYC genes that encode key enzymes in the
carotenoid pathway.
P01-117: ROLE OF CD AND CU ON THE ANTIOXI-
DANT BEHAVIOUR OF BRACHYCHITON POPULNEUS
(SCHOTT & ENDL.) R. BR. (STERCULIACEAE)
Baycu, G. 1 * - Bakacak, S.A. 1 - Rognes, S.E. 2
1
Istanbul University
2
Oslo University
*Corresponding author, e-mail: gbaycu@gmail.com
Brachychiton populneus (Bottle tree) occurs naturally in southern
Australia. Young seedlings distribute resources to form a large
tap-rooted tuber that has considerable starch and water reserves,
allowing the tree to survive in the dry and hot periods of Mediterranean
environment. Brachychiton is commonly cultivated and
is hardy in a range of climates and soils. Oxidative stress is induced
by a wide range of environmental factors including drought,
heat and trace metal stresses. The aim of this study was to examine
the antioxidant behaviour of this drought tolerant plant to
trace metal toxicity. Plant seeds were collected from Cyprus Island,
which has a typical Mediterranean climate. We had some
difficulties during the germination and plant growth in hydroponic
cultures was impossible. For this reason sand & perlite cultures
were set up and plants were grown for several months in
the phytotrone conditions. The seedlings were then treated with
50-150μM Cd and 500-1500μM Cu for 2-week to investigate the
role of Cd and Cu on the activity of catalase (CAT), glutathione
reductase (GR) and guaiacol peroxidase (GPOX) in the leaves
and roots. The activity of CAT was diminished both by Cd and
Cu toxicity in the plant organs. GR activities were reduced by
both metals in the leaves except a slight increase in the low Cd
treatment. No changes in GR activity were observed in the roots.
Conversely, both Cd and Cu produced a raise in GPOX activity
in the leaves. Whereas an increase was observed with low Cd and
low Cu treatments in the roots, high Cd and high Cu reduced the
activity. GPOX could be exerting a stronger antioxidant function.
These results suggest that antioxidant behaviours may change
with various trace metal concentrations in different plant organs.
P01-118: THE ROLE OF SALT (NACL) STRESS AND
CALCIUM ON ION ACCUMULATION (MN, MO, ZN, CU,
FE) IN SOYBEAN [GLYCINE MAX (L.) MERR.]
Cetin E 1 * - Caglayan A 2 - Kiziler A R 3
1
Istanbul University
2
Bahcesehir Ataturk Highschool
3
Namik Kemal University
*Corresponding author, e-mail: ergulc@istanbul.edu.tr
In this study, the role of NaCl stress and Ca on the accumulation
of Mn, Mo, Zn, Cu, Fe ions in the stem and leaves of Glycine
max A-3935 was investigated. In the first part of the experiment
carried out in hydroponic cultures, six different concentrations
of NaCl (0, 20, 40, 60, 80, 100 mM) were applied. In the second
part, two diffferent Ca concentrations (60+6, 80+6, 100+6, 60+9,
80+9,100+9 mM NaCl+Ca) were added.
The accumulation amounts of Mn, Mo, Zn, Cu and Fe ions (μg/g
DW) in stem and leaves of the plants were measured by Atomic
Absorption Spectrophotometer (AAS).
Along with the increased NaCl concentration in the hydroponic
medium Mo, Zn and Cu ion accumulations were increased while
Mn ion concentration was decreased in the stems. We have not
found any significant decrease or increase in Fe ion accumulation.
After the addition to Ca concentrations, Mo, Zn, Cu and Fe
ion accumulations were decreased. However Mn ion accmulation
was increased in the stems.
Along with the increased NaCl concentration in the hydroponic
medium Mo, Cu and Fe ion accumulations decreased in the
leaves. 8Whereas Mn and Zn ions were not significantly increased
or decreased.
The effect of additional Ca concentrations caused a decrease in
Zn and Cu ion accumulations. According to 100 mM NaCl concentration
Fe ion accumulation was increased.
P