INVESTIGADORES
BARTOLI Carlos Guillermo
congresos y reuniones científicas
Título:
Brassinosteroids-ethylene interaction for the regulation of ascorbic acid synthesis in tomato leaves.
Autor/es:
MAZORRA, LUIS MIGUEL; SENN, MARÍA EUGENIA; GERGOFF GROZEFF, GUSTAVO; FANELLO DIEGO DARÍO; CARRIÓN, CRISTIAN; BISHOP, GERARD; BARTOLI CARLOS GUILLERMO
Lugar:
Mar del Plata
Reunión:
Congreso; XXIX Reunión Argentina de Fisiología Vegetal.; 2012
Institución organizadora:
Asociación Sociedad Argentina de Fisiología Vegetal
Resumen:
The aim of our research is to gain
better understanding of the hormonal control of ascorbic acid synthesis and
accumulation in plants.
We focused our analysis on the
effect of plant steroid hormones (Brassinosteroids-BRs) on tomato (Solanum lycopersicum L. cv Ailsa Craig)
leaves by utilising BRs deficient mutants (dx)
and lines over-accumulating BRs (35S:D). Plants were grown at 300 µmol m-2
s-1 (PPFD) at 23 ºC
for two weeks (16/8hr light/dark, respectively). Leaves from the dx plants showed lower
ascorbic acid content and reduced capacity to synthesise ascorbic acid than
non-modified tomato plants. 35S:D leaves have similar amount of ascorbic acid
content to wild type but have a higher capacity to synthesise this metabolite.
Ethylene production rates and
its capacity of synthesis (i.e. ethylene production after incubation leaves
with its precursor aminocyclopropane-1-carboxylic acid) was higher in dx but not in the 35S:D
leaves compared with those that have normal BRs content. To study the
participation of BRs in the ethylene-mediated antioxidant accumulation, plants
were treated with the ethylene action inhibitor 1-methyl cyclopropene (1-MCP).
This treatment was performed by placing plants in 40 L chambers containing 1µL L-1
1-MCP overnight. When ethylene signalling was blocked, ascorbic acid content
and synthesis capacity enhanced twice in dx
plants but decreased in 35S:D leaves. These results demonstrate that BRs and
ethylene signalling pathways interact for the control of the level and
synthesis capacity of ascorbic acid in leaves of tomato plants.
Further analysis will be
focused on the involvement of BRs regulation on photosynthesis and respiration
metabolism including antioxidant accumulation.