Book of Abstracts - Geyseco

P - Posters
Gould, P.¹ - Foreman, J.² - Domijan, M.³ - Piñas Fernández, A.² -
Costa, M.³ - MacGregor, D.4 - Zielinski, T. ² - Steward, K.² - Bird,
S.4 - Steel, G.² - Williams, M.² - White, M.¹ - Graham, I. 4 -
Penfield, S. 4 - Finkenstadt, B.³ - Rand, D.³ - Millar, A.² - Hall,
A¹ - Halliday, K.²
¹University of Liverpool
²University of Edinburgh
³University of Warwick
4University of York
Changes in ambient temperature can have dramatic consequences
for plant development and physiology. Temperature changes
alter the reaction rates of individual biochemical processes;
therefore, a biological network must balance the effects of these
alterations in each of its components to retain signalling integrity
over a temperature range. ROBuST seeks to understand the
principles that underlie SENSITIVITY and ROBUSTNESS of
a biological network. Our study network comprises the interconnected
network of light, cold acclimation and the circadian
pathways. Our work has identified a new and prominent function
for cry1, cry2, and phyA as regulators of temperature buffering
of the circadian clock. Deficiencies in cry1 and cry2 resulted in
failure of the clock transcriptional feedback loop under warm
temperatures, and phyA deficiency under cold. This work has led
to i) the development of temperature compensated plant clock
model, and ii) evidence the co-evolution of light and temperature
signal transduction.
P03-014: METABOLITE ANALYSIS OF AN ABA-DEFI-
CIENT MUTANT OF SWEET ORANGE DURING RIPE-
NING AND POSTHARVEST STORAGE
Romero, P. 1 * - Lafuente, M.T. 1 - Reyes-de-Corcuera, J.I. 2 -
Alférez, F. 1 - Zacarías, L. 1 - Rodrigo, M.J. 1 - Burns, J. K. 2
1
Instituto de Agroquímica y Tecnología de Alimentos (IATA-
CSIC)
2
Citrus Research and Education Center, University of Florida
*Corresponding author e-mail: ciepro@iata.csic.es
‘Pinalate’ is a yellow-colored spontaneous mutant fruit from
the ‘Navelate’ orange (Citrus sinensis L. Osbeck). Carotenoid
biosynthesis is blocked in this mutant, resulting in abscisic acid
(ABA) deficiency and accumulation of non-coloured carotenoids.
Fruit of this mutant display altered ripening and increased
susceptibility to peel pitting during storage at non-chilling
temperatures (12ºC). Flavedo (colored part of the peel) samples
from both cultivars were collected at several ripening stages and
stored at various durations at 12 ºC to characterize their metabolic
profile by GC-MS.
Compounds were identified and grouped into amino acid, sugar,
polyalcohol and organic acid families. All identified sugars increased
during ripening in both cultivars; however, sucrose content
fluctuated and reached higher values in mutant mature fruit.
Other compounds such as serine and ribitol
decreased with ripening while indole-3-acetic and mannoonic
acids sharply increased at the last ripening stage in both varieties.
The results also showed that at 12 ºC most sugars similarly
decreased in both cultivars. Among organic acids, only hexadecanoate
showed a different pattern, reaching higher levels in ’Pinalate’
after prolonged storage. Taken together, the results revealed
that only sucrose and hexadecanoate of studied compounds
showed differences between ‘Navelate’ and ‘Pinalate’ fruits,
suggesting that these changes may be associated with the altered
behavior of ‘Pinalate’ mutant.
P03-015: A REVERSE GENETICS APPROACH TO THE
ANALYSIS OF LEAF DEVELOPMENT
Muñoz-Viana, R. - Rubio-Díaz, S. - Pérez-Pérez, J.M. - Wilson-
Sánchez, D. - Ponce, M.R. - Micol, J.L.
División de Genética and Instituto de Bioingeniería, Universidad
MiguelHernández, Campus de Elche, Alicante, Spain
Because of their photosynthetic activity, leaves are the ultimate
source of most of the oxygen that we breathe and of the food that
we eat. Yet the processes by which these organs grow are poorly
understood. Previous forward genetics studies yielded a large
number of mutations affecting Arabidopsis leaf development,
shape or size. However, none of these earlier attempts reached
genome saturation. The group of Prof. J.R. Ecker at the Salk Institute
is obtaining a large collection of gene-indexed homozygous
T-DNA insertion mutants that will cover 25,000 genes of the
Arabidopsis genome. To identify novel genes required for leaf
growth regulation, we have begun a reverse genetics screening
using the 14,000 T-DNA insertion lines available in batches from
the ABRC, which correspond to 10,800 different Arabidopsis genes.
These lines are grown in vitro and those exhibiting aberrant
leaf phenotypes are documented and kept for further studies. In
order to saturate the Arabidopsis genome with viable and fertile
leaf mutations, we plan to screen the entire Salk homozygous T-
DNA insertion collection for visible leaf phenotypes.
P03-016: A COLLECTION OF AMIRNAS TARGETING
GROUPS OF TRANSCRIPTION FACTOR-ENCODING
PARALOGS
Ponce, M. - Jover-Gil, S. - Micol, J.L.
División de Genética and Instituto de Bioingeniería, Universidad
Miguel Hernández, Campus de Elche (Alicante), Spain
Our understanding of the function of individual Arabidopsis genes
is obscured by the existence of gene families that include redundant
members. In fact, there is an expanding list of single null
mutants not exhibiting a mutant phenotype. In addition, examples
are known of double and even triple combinations of non-allelic,
loss-of-function mutations affecting paralog genes that cause no
visible phenotypes. The masking effects of redundancy in gene
families can be overcome with new technologies based on gene
silencing using artificial microRNAs (amiRNAs). We are obtaining
transgenic Arabidopsis lines expressing amiRNAs designed
to repress groups of paralog genes encoding transcription factors.
These amiRNAs were designed to target groups of two or more
transcription factor-encoding genes that are arranged in tandem
in the Arabidopsis genome. Following the design principles that
can be found at http://wmd.weigelworld.org, we already designed
197 amiRNAs, 164 of which have already been transferred to
Arabidopsis plants. Three well known transcription factor-encoding
genes with easily visible loss-of-function phenotypes were
chosen as controls: GL1, AG and PAP1. In most, but not all cases
the transgenic plants obtained exhibited the phenotype expected
from downregulation of the target gene.
P03-017: METABOLIC PROFILES CAN ASSIST TO DIS-
CRIMINATE CAULIFLOWER GROWN UNDER DIFFE-
RENT FARMING PRACTICES
Annunziata, M. – Massaro, G. – Iannuzzi, F. – Nacca, F. – Carillo,
P. - Fuggi A.
Dipartimento di Scienze della Vita, Seconda Università di Napoli,
Caserta Keywords: cauliflower, Brassica oleracea L. Subsp
botrytis, carbohydrates, aminoacids, glucosinolates The conventional
cauliflower culture needs high inputs of fertilizers and
pesticides, that can cause soil pollution and degradation. On the
other hand, the demand of better foods and the use of more sustainable
agricultural practices is increasing. In this view the aim
of this work was to verify if metabolite profiling can discriminate
among farming practices and assist in tracing the produce. Cauliflower
(Brassica oleracea subsp. botrytis cv Atalaya) plants were
grown under traditional farming system (TFS) and conservative
(low tillage) farming system (CFS). At the harvest the corymb
heads were divided in curd (immature flowers) and stem, frozen
and homogenised in liquid nitrogen. Aliquots were used to
determine the content of protein, carbohydrates, ascorbate and
glutathione, inorganic and organic acids, free amino acids and
glucosinolates. Five individual plants were used as replicates.
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