Book of Abstracts - Geyseco

P13
Metabolism
P13-001: DYNAMICS OF PHOSPHOLIPIDS’ CHANGES
IN FRUITS OF COTTON
Zikiryayev, A.* - Begimkulov, U.
Tashkent State Pedagogical University
*Corresponding author, e-mail: AZikiryayev@yandex.ru
In spite of the fact that phospholipids, glicolipids and sterins are
contained in various bodies of cotton (seeds, fiber) in rather small
quantities, their value in metabolic processes of plants is exclusively
great. Last years the great attention is paid to lipid exchange
as a factor of adaptation to environmental conditions. Lipids’
participation in particular of phosphotidilglicerin, in stability of
plants from cooling is supposed. According to F.I Roslyno, changes
in lipid and fatty acid structure under the influence of water
stress affect structurally functional peculiarities of membranes
and consequently on photosynthetic activity of chloroplast of
cotton leave. At the same time lipids play the important role in
cellulose formation in fruits of cotton.
Study of phospholipids’ structure in different periods of maturing
of various parts of fruits of cotton has shown that phospholipids
are important in their formation. The special attention is deserved
natural change of general phospholipids’ maintenance and their
components in developing fibers. Change of phospholipids structure
of fibers is connected with reducing of one components and
increasing the others. In such way phosphotidilholin, phosphotidilcirin,
phosphotidilinozit are able to be changed. Distinctions
of phospholipids are connected with formation of cotton fibers.
Justification of it is that the maintenance phospholipid is full during
this period when there is an intensive growth and development
of cells of fibers i.e. at the day age of 15-30.
Further study of phospholipids’ accumulation and exchange in
bottoms and especially in a fiber is of a huge theoretical and practical
importance in connection with clarifying of the mechanism
of cellulose biosynthesis in fruits of cotton.
P13-002: A SINGLE ACTIVE TREHALOSE-6-P SYNTHA-
SE (TPS) AND A FAMILY OF PUTATIVE REGULATORY
TPS-LIKE PROTEINS IN ARABIDOPSIS.
Rolland, F. 1 * - Vandesteene, L. 1 - Ramon, M. 2 - Le Roy, K. 1 - Van
Dijck, P. 1
1
K.U.Leuven
2
Massachusetts General Hospital, Harvard U.
*Corresponding author, e-mail: filip.rolland@bio.kuleuven.be
The disaccharide trehalose is commonly found in bacteria, fungi
and invertebrates, where it functions as a reserve carbohydrate
and stress protectant with its unique physico-chemical properties.
However, trehalose is not synthesized in vertebrates and while it
accumulates in non-vascular and lower vascular plants like algae,
liverworts, mosses and ferns (some of which are known as
extremely drought-tolerant ‘resurrection’ plants), typically only
minute amounts are produced in higher plants. Still, most higher
plant genomes analyzed up till now contain large trehalose biosynthesis
gene families and (heterologous) over-expression and
mutation of trehalose biosynthesis genes or external trehalose
feeding have marked effects on growth, stress tolerance, photosynthetic
activity and carbon partitioning. An important regulatory
role is emerging for the metabolic intermediate trehalose-6-P
(T6P), which acts at least in part through inhibition of the SnRK1
P - Posters
protein kinases. Systematic gene expression and yeast complementation
analyses of the entire family of T6P synthase (TPS)
and T6P phosphatase (TPP) proteins suggests that in addition to
a single TPS (TPS1, essential for embryo maturation and normal
vegetative and reproductive growth) and a family of active TPP
enzymes, Arabidopsis also encodes a whole family of catalytically
inactive TPS/TPP-like proteins (TPS2-11) with putative tissue
or cell type specific regulatory functions. We are using modeling
and mutational analyses to study the putative conserved
binding of substrate metabolites and associated functions of these
proteins as metabolic sensors.
P13-003: BARLEY CYSTEINE PROTEASES OF C1A
CLASS: MOLECULAR CHARACTERIZATION AND RO-
LES IN PLANT PROTEOLYTIC PROCESSES
Cambra, I. - Martínez, M. - Dader, B. - González-Melendi, P. -
Diaz, I.
CBGP
Plant proteolysis is a complex process involving many different
pathways and cellular compartments. Protease activities are
regulated at the transcriptional level by differential expression
and at the protein level by the activation of zymogens and by
the binding of specific inhibitors and cofactors. We have focused
our attention on the cysteine-protease class (CysProt) which
comprises about 140 members among the 800 proteases encoded
by angiosperm genomes. Particularly, we study the papain-like
proteases (family C1, clan CA) from barley which includes 32
proteins. These CysProt participate in many physiological processes
as protein degradation during senescence and abscission
process, programmed cell death, accumulation and mobilization
of storage proteins in seeds and tubers, or in protein processing.
We aim to understand their physiological roles by identifying the
targets involved in specific proteolytic process, the fulfilment of
their functions, their responses to different stimuli and the regulation
of their activities. Up to now, we have molecularly characterised
at least one member of each of the 8 main groups in which
the 32 barley CysProt have been clustered. In addition, the whole
cystatin gene family encoding cysteine-protease inhibitors from
barley has also been characterised. Currently we are analyzing
the protease-cystatin relationships: expression patterns, protein
locations, protein-protein interactions, differential responses to
abiotic and biotic treatments, and finally their implication in specific
physiological processes.
This work is supported by the Spanish Ministerio de Educación y
Ciencia (BFU2008-01166) and by the Agencia Española de Cooperación
Internacional (A/017236/08).
P13-004: GLUCOSE 1-PHOSPHATE TRANSLOCATORS
IN PLASMA- AND IN PLASTIDIAL ENVELOPE MEM-
BRANE FROM HIGHER PLANTS
Fettke, J.*
University of Potsdam AG Plant Physiology
*Corresponding author, e-mail: fettke@uni-potsdam.de
For several glucosyl transfer reactions glucose 1-phosphate is
an essential metabolite that acts either immediately as glucosyl
donor or as a substrate for the formation of the more general donors,
ADPglucose and UDPglucose. We analyzed two glucose
1-phosphate related transport processes: the uptake by the cells
and the import into intact plastids. Glucose 1-phosphate is taken
up by both autotrophic and heterotrophic cells. The glucose
1-phosphate uptake is highly specific for the anomeric position
of the phosphate ester as glucose 6-phosphate does not substitute
the carbon 1 ester. Following uptake, glucose 1-phosphate is
imported into the plastids and subsequently enters starch biosynthesis.
As revealed by in situ and in vitro labeling experiments, at
least two distinct starch synthesizing paths exist: First, in a single
reaction (that is mediated by the plastidial phosphorylase isozyme)
glucosyl residues are transferred from glucose 1-phosphate
P