INFIVE   05416
INSTITUTO DE FISIOLOGIA VEGETAL
Unidad Ejecutora - UE
artículos
Título:
Expression of a lipoxygenase encoding gene (BoLOX1) during postharvest senescence of broccoli.
Autor/es:
GÓMEZ LOBATO ME; CIVELLO, PM; MARTÍNEZ GA
Revista:
POSTHARVEST BIOLOGY AND TECHNOLOGY
Editorial:
ELSEVIER SCIENCE BV
Referencias:
Lugar: Amsterdam; Año: 2012 vol. 64 p. 146 - 153
ISSN:
0925-5214
Resumen:
Lipoxygenases (LOX) belong to a large family of plant enzymes that
catalyze the hydroperoxidation of polyunsaturated fatty acids. Most of
them are expressed during senescence and contribute to membrane
deterioration and biosynthesis of jasmonic acid, a known senescence
enhancer. In this work, we cloned a fragment of a gene encoding a LOX
from broccoli (BoLOX1). The analysis of the sequence revealed that BoLOX1 is closely related to other LOX from higher plants. Furthermore, we analyzed the expression of BoLOX1
and detected a larger increase during postharvest senescence. A slight
increase of total lipoxygenase activity was also found during
senescence. In other sets of experiments, broccoli heads were treated
with plant hormones, such as cytokinin and ethylene, as a way to assess
the effect of such compounds on the expression of BoLOX1. Cytokinin treatment delayed the increase of BoLOX1
expression and lipoxygenase activity whereas ethylene accelerated both
processes. Also, several postharvest treatments were applied in order to
delay senescence in broccoli florets and to evaluate their effects on BoLOX1
expression. Samples treated with modified atmosphere, hot air, UV-C or
white light showed a delay in chlorophyll degradation and degreening. In
most cases, the treatments also delayed the increase of BoLOX1
expression, reaffirming the relationship between the expression of this
gene and senescence. However, treatments like modified atmospheres and
visible light markedly increased lipoxygenase activity, which suggests a
lack of correlation between BoLOX1 expression and lipoxygenase activity.