acta societatis botanicorum poloniae - LV Zjazd Polskiego ...

55th Meeting of the Polish Botanical Society, Warsaw 2010
tion in shoots of Nicotiana tabacum. Tests were performed on
plants grown within a range of Zn concentrations (0,4– 100μM)
to assess: Zn dependent regulation of AhHMA4 expression in
tobacco, Zn accumulation, tolerance level and expression of
NtIRT1 (IRT1 is involved also in Zn and Cd uptake). Only upon
10μM Zn resupply to plants treated with 0,4μM Zn was the modification
(decrease) of AhHMA4 expression detected. NtIRT1
expression was altered in a Zn-dependent manner in AhHMA4
plants. Increased Zn level in leaves of transgenics grown at low
Zn (0,4μM, 0,8μM) makes AhHMA4 a good candidate for biofortification
purposes. Acknowledgements: Supported by FP6
EU PHIME project (FOOD-CT-2006-016253).
HYPOxIA-INdUCEd CHANGES IN THE INTENSITY
OF PHOTOSYNTHESIS ANd rESPIrATION, ANd
MALATE ANd CITrATE CONTENT IN THE GAMETO-
PHOrES OF MOSSES
rut Grzegorz, rzepka Andrzej, Krupa Jan. Pedagogical
University, Department of Plant Physiology, 3 Podbrzezie St.,
30-054 Cracow; grut@up.krakow.pl; rzepkazf@up.krakow.pl;
krupazf@up.krakow.pl
Mosses are plants with a simple anatomical leaf structure.
These plants occur in habitats where external factors can fluctuate
widely, and are often exposed to stress resulting from
a shortage or excess of water. The injuries to green plants during
submergence in water are associated with a reduced access
to oxygen but also caused by carbon dioxide dissolved in water.
After 24 h hypoxia, the intensity of net photosynthesis drops in
the gametophores of M. undulatum by 35% and in P. piliferum
by 88%, compared with the values before submergence. The
intensity of respiration, however, increases by ca. 25– 30%. As
a result of submergence in water, the nature of reactions associated
with the photosynthesis and respiration, and with the accompanied
transformation of malate and citrate in moss gametophores,
change. Immersing moss in water causes an increase
in daily fluctuations of the malate content, particularly in the
gametophores of P. piliferum. The changes in citrate content in
plants kept under hypoxia are, however, much lower than those
in malate. Metabolism of malate and citrate is associated with
either an uptake or release of CO2, accompanied by changes in
NAD(P)-ME activity. The increased daily fluctuations of malate
and NAD(P)H in the species studied in hypoxia, may constitute
an important element of their adaptive strategy to stress conditions.
COLd AFFECTS THE ACTIVITY OF PECTIN METHY-
LESTErASES ANd THE dEGrEE OF PECTIN METH-
YL-ESTErIFICATION IN MAIZE LEAVES
Solecka danuta1 , Bilska Anna2 , dziewulska Aleksandra1 ,
Sowiński Paweł1,2 . 1University of Warsaw, Department of Plant
Molecular Ecophysiology, IEPB, 1 Miecznikowa St., 02-096
Warsaw, Poland; solecka@biol.uw.edu.pl; 2Institute of Plant
Breeding and Acclimation, Radzików, 95-870 Błonie, Poland
Cold springs disturb maize growth and development, which depend
on cell wall properties. In the presented experiments we
have checked whether cold modifies the degree of pectin methyl-esterification
and activity of pectin methylesterases (PME),
The PME activity is an important factor for changing the cell
wall mechanical properties. Maize seedlings of two lines: KW
1074 (chilling-tolerant) and CM 109 (chilling-sensitive) were
exposed to cold (+14ºC) for 7 days. Samples were harvested
4 times during the cold treatment. The activity of PME was
measured spectrophotometrically, using highly-methylated citrus
pectin and Methyl Red as substrates. Immunohistochemical
localization of epitopes of highly- and low-methylated pectins
was accomplished using the monoclonal antibodies JIM 7 and
JIM 5, with electron microscope JEM 1400 (Laboratory of Elec-
92
tron Microscopy, the Nencki Institute, PAS, Warsaw, Poland).
Obtained results show that the PME activity, pectin content and
the level of pectin methylation clearly decreased in CM 109
leaves in response to cold treatment, in contrast to the KW 1074
line. These changes in cell wall pectin status may indicate the
degradation of cell wall structure. The phenomenon may have
far-reaching consequences for resistance of the cells to cold and
other common stress factors such as pathogen attack, occurring
during early spring.
CYANAMIdE ALLELOPATHIC ACTION ON rOOT
GrOWTH OF TOMATO (lycoPersicon esculentum)
ANd MAIZE (zeA mAys)
Sołtys Dorota, Wiśniewska Anita, Gniazdowska Agnieszka,
Bogatek renata. Warsaw University of Life Sciences – SGGW,
Department of Plant Physiology, 159 Nowoursynowska St.,
02-776 Warsaw, Poland, ana_solys@wp.pl
Calcium cyanamide is a well known fertilizer. In soil it is decomposed
into active cyanamide (CA) and calcium hydrogen.
As a natural compound, CA is produced by hairy vetch (Viccia
villosa), bird vetch (Viccia cracca) and black locus (Robinia
pseud acacia). Hairy vetch as a green manner or cover
crop is a natural weed inhibitor. The aim of our studies was
to investigate some mechanisms of CA allelopathic action on
root elongation growth of young tomato (Lycopersicon esculentum)
and maize (Zea mays) seedlings. Expansins gene expression,
emission of ethylene in vivo and in vitro (in the presence
of 1-aminocyclopropane-1-carboxylic acid (ACC)) and auxin
(indole-3-acetic acid (IAA)) concentration in roots of young
seedlings were determined. CA inhibited seedling root growth.
The CA inhibition reaction was more pronounced in tomato
than in maize. CA decreased expression of expansin genes in
tomato root, and provoked transient increase in ethylene emission.
Some alterations in IAA concentration were detected after
CA treatment. Modification of hormonal balance in maize and
tomato roots in response to CA will be discussed.
INVOLVEMENT OF ABA ANd NO IN rEGULATION OF
APPLE EMBrYO dOrMANCY ALLEVIATION, GEr-
MINATION ANd GrOWTH OF YOUNG SEEdLINGS
Szafrański Kamil, Krasuska Urszula, Dębska Karolina,
Gniazdowska Agnieszka, Bogatek renata. Warsaw University
of Life Sciences – SGGW, Department of Plant Physiology,
159 Nowoursynowska St., 02-776 Warsaw, Poland, kamil_
szafranski@sggw.pl
Seed dormancy and germination are regulated by a phytohormone
balance between gibberellins (GAs), ethylene and abscisic
acid (ABA). Expression of dormancy depends on ABA level
or its sensitivity in seeds. The interaction between ABA and
NO in the regulation of many physiological processes in plants
is well documented. NO together with ROS are considered as
signaling molecules involved in seed physiology. The aim of
our work was to investigate the effect of NO on ABA metabolism
in germinating apple (Malus domestica Borkh.) embryos.
Germination of embryos isolated from dormant apple seeds
was stimulated by short term-fumigation by NO. This was accompanied
by decreased sensitivity of the embryos to exogenous
ABA. Fluridone, inhibitor of ABA synthesis, stimulated
germination of both control (non-treated) and NO pre-treated
embryos, but blocked development of the seedlings and completely
abolished chlorophyll biosynthesis. ABA concentration
was high in dormant control embryos and decreased rapidly
after NO treatment. Later on, during the culture, a marked
increase in concentration of the hormone in embryos was noticed.
Interaction between NO and ABA in the regulation of
dormancy removal and development of young seedlings will
be discussed.