Book of Abstracts - Geyseco

P - Posters
Plants harboring PYK10-CKX3 were crossed with four different
transgenic lines with enhanced leaf growth. For all combinations
both phenotypic traits could be combined resulting in overall
yield increase. Both leaf and root growth were synergistically enhanced
in plants ectopically expressing CKX3 and BRI1 (Brassinosteroid
Insensitive 1), indicating crosstalk between cytokinins
and brassinosteroids. Treatment of PYK10-CKX3 plants with
brassinolide showed a dramatic increase in lateral root growth
that could not be observed in wild type plants. Co-expression
of CKX3 and GRF5 (Growth Regulating Factor 5) antagonized
the effects of GRF5 overexpression, revealing interplay between
cytokinins and GRF5 during leaf cell proliferation. Combined
overexpression of CKX3 and GA20ox1 (Gibberellin 20-oxidase
1) led to a synergistic increase in leaf growth, suggesting that
cytokinins act together with gibberellins. On the other hand, only
additive effects on root and shoot growth could be observed in
plants ectopically expressing both CKX3 and the vacuolar pyrophosphatase
AVP1, indicating an independent mode of action.
P03-005: METABOLOMIC ANALYSIS OF VANILLA
PLANTS FROM DIFFERENT SPECIES AND IMPACT
OF CYMBIDIUM MOSAIC VIRUS (CYMMV) ON THE
GROWTH AND METABOLOME OF VANILLA VINES
Palama, T.¹* - Grisoni, M.¹ - Fock, I.¹ - Jade, K.¹ - Bartet, L.¹ -
Choi Y, H.² - Verpoorte, R.² - Kodja, H.¹
¹UMR PVBMT, Université de La reunión
²Division of Pharmacognosy, Section Metabolomics, IBL, Leiden
University
*Corresponding author e-mail: tony.palama@univ-reunion.fr
More than 110 species are comprised in Vanilla genus which belongs
to the Orchidaceae family. Nevertheless, only three species
are commercially cultivated (V. planifoliaV, . tahitensis and V.
pompona) with V. planifolia pods being the major source of natural
vanilla flavour. In order to increase vanilla pods production,
a more intensive cultivation system is now employed. However,
this cultivation system facilitated the spread of viruses like the
Cymbidium mosaic virus (CymMV). Investigation of the effect
of CymMV on the growth and metabolome of vanilla plants was
performed by growing four Vanilla accessions: CR01 (V. planifolia),
CR17 (V. tahitensis),CR03 (V. planifolia × V. tahitensis) and
CR18 (V. pompona). CymMV infected plants of CR01, CR03 and
CR17 have a reduced growth (vines and internodes length, stem
diameter and number of leaves). Nevertheless, there is no significant
difference in the growth of CR18. Methanol-water extracts
of Vanilla leaf were analyzed by 1 H NMR spectroscopy. Metabolomic
analysis of the leaves showed a difference of profile according
to the species. It appears that CR18 leaves had qualitatively
more phenolic compounds than the others accessions. However,
no discrimination based on the CymMV infection status was possible
for samples collected from the field. Another metabolomic
analysis was performed under in vitro conditions with V. planifolia
plants infected by CymMV. An increase of amino acids and
sugars levels of CymMV infected leaves was observed, whereas
phenolic compounds and malic acid levels decreased. This study
was the first metabolomic analysis performed on Vanilla plants
from different species. Nevertheless, further studies are required
on the earlier mechanism of CymMV infection.
P03-006: VANILLA REGENERATION THROUGH SHOOT
FORMATION FROM PROTOCORM CALLUS: META-
BOLOMIC AND PROTEOMIC ANALYSIS AT EARLY
STAGE.
Kodja, H.¹* - Palama, T.L.¹ - Fock, I.¹ - Choi Y, H.² - Bourdon,
E.¹ - Verpoorte, R.²
¹Université de La Reunión
²University of Leiden
*Corresponding author e-mail: kodja@univ-reunion.fr
Vanilla planifolia is an important Orchid commercially cultivated
for the production of natural vanilla flavour. Because mass
production of V. planifolia through indirect shoot differentiation
from callus culture is rare and may be a successful use of in vitro
techniques for producing somaclonal variants, we have established
a novel protocol for the regeneration of vanilla plants and
investigated the initial biochemical and molecular mechanisms
that trigger shoot organogenesis from embryogenic/organogenic
callus. By associating proteomics and metabolomics analyses,
the biochemical and molecular markers responsible for shoot induction
have been studied in 15-day-old calli at the stage where
no differentiating part was visible on calli. The subculture of embryogenic/organogenic
calli onto shoot differentiation medium
triggers the stimulation of cell metabolism principally at three
levels namely (i) initiation of photosynthesis, glycolysis and phenolic
compounds synthesis; (ii) amino acid – protein synthesis,
and protein stabilization; (iii) sugar degradation. These results
might contribute to elucidate the complex mechanism that leads
to vanilla callus differentiation and subsequent shoot formation
into PLB organogenesis. Moreover, histological analysis showed
that the nearby presence of starch could be an important factor in
organogenesis of PLB. These observations confirm that Orchid
seeds cannot reach the seedling stage without an external supply
of carbohydrates which is provided in nature by fungi mycorrhizae.
P03-007: THE ART NOUVEAU OF SYSTEMS BIOLOGY
(ON HOW TO MODEL NATURAL ORGANIC FORMS)
Sauret-Gueto, S.* - Sablowski, R. – Coen, E.
John Innes Centre
*Corresponding author e-mail: susana.sauret-gueto@bbsrc.
ac.uk
Developmental biology have long tried to understand how the
organisms acquire their mature shape. A fascinating example
is flower development, where undifferentiated primordia will
shapeinto one of the four types of floral organs: sepals, petals,
stamens and carpels. In the last two decades we have begun to
understand how genes products control the identity, number and
positioning of floral organs in each whorl but If we want to understand
how gene activity is translated into a morphological
form we need to address growth as a dynamic process and construct
mechanistic models. In plants, shape is generated as a result
of two local variables: growth rate and growth direction. Two
basic types of data provide information on how growing shapes
emerge: 1) growth studies such as tracking and clonal analysis
provide access to growth patterns and 2) molecular genetic studies
provide information on patterns of gene activity. A major
challenge is to link these two types of data. We have generated
a quantitative framework for the Arabidopsis petal and clonal
analysis is being used to infer its growth patterns. We are following
a computational approach to understand how gene activity
influences the development of tissue shape. Tissue is treated
as continuum and genetically controlled factors, that interact and
propagate, are inputs that locally control growth rate and growth
direction. As a result these factors specify local strain fields and
elasticity theory is used to compute the resulting deformations at
a higher level, the continuum tissue. In a crosstalk of approaches,
computational generated models are contrasted with mutant phenotypes
and gene activities to generate new hypothesis on how
Arabidopsis petal shape is generated at the tissue level.
P03-009: XYLEM METABOLOMICS AND IRON DEFI-
CIENCY
Rellán-Álvarez, R.¹ - El Jendoubi, H.¹ - Wohlgemuth, G.² - Abadía,
A.¹ - Fiehn, O.² Abadia, J.¹ - Álvarez-Fernández, A.¹
¹Aula Dei Experimental Station-CSIC
²University of Calfornia-Davis
Xylem sap provides an interesting system to study plant metabolism.
Xylem is the highway for metabolite traffic between roots
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