Phospholipase A2 and postharvest peel pitting in citrus fruit

ABA-deficiency and molecular mechanisms involved in the dehydration response and ripening of citrus fruit

“…During postharvest handling of fruits of agronomic interest, water stress is one of the most important factors reducing the external quality and hence the commercial value. However, the study of the molecular responses during dehydration in harvested fruit has been limited to a few set of genes (Alférez et al, 2008;Bonghi et al, 2012;Loyola et al, 2012), and global changes occurring in fruits under water stress conditions was only performed in grapes (Grimplet et al, 2007;Rizzini et al, 2009;Deluc et al, 2009;Zamboni et al, 2010).…”

“…However, the study of the molecular mechanisms underlying fruit dehydration has been limited to a few sets of genes involved in secondary metabolism and ABA signalling and biosynthesis (Schwartz et al, 1997;Burbidge et al, 1999;Alférez et al, 2008;Bonghi et al, 2012;Loyola et al, 2012). In order to get an overview of the biological processes playing a role in the fruit stress tolerance, transcriptomic research has been performed in grapes.…”

“…Therefore, the metabolic pathways of these compounds have been largely investigated (Seki et al, 2007) although regulatory networks and cross-talk between their components need further investigation (Yamaguchi- Shinozaki and Shinozaki, 2006;Shinozaki and Yamaguchi-Shinozaki, 2007). Deregulation of these water stress metabolites and/or responsive genes can be finally manifested as cellular damaged tissues (Alférez et al, 2008). Moreover, mechanisms occurring in grape berries dehydrated after harvest (Grimplet et al, 2007;Zamboni et al, 2010) or in berries from water-stressed vines (Deluc et al, 2009) indicated that dehydration may have a profound effect on the expression of genes associated with the biosynthesis of relevant compounds that ultimately impact fruit quality.…”

“…However, the study of the molecular mechanisms underlying fruit dehydration in horticultural crops has been limited to a few set of genes (Alférez et al, 2008;Bonghi et al, 2012;Loyola et al, 2012), and high throughput approaches have been only performed in grape and citrus fruit. Studies in grapes indicate that molecular responses are differently regulated by dehydration occurring before or after harvesting the fruit and also by the stress severity (Deluc et al, 2009;Rizzini et al, 2009;Bonghi et al, 2012).…”

Estudio transcriptómico de los mecanismos implicados en la tolerancia inducida por el curado al daño de frío y por el etileno al colapso de la corteza en los frutos cítricos.

“…Por otro lado, se ha comprobado que el acondicionamiento de los frutos con etileno (10 μL L -1 ), que fue muy efectivo reduciendo el 'colapso de la corteza', aumentó significativamente la actividad GR en frutos de 'Navelina' y como se ha mencionado, también la actividad de la enzima POD y el contenido de fenoles totales, que constituyen la mayor proporción de compuestos antioxidantes en la piel de los frutos cítricos (Manthey, 2004), en el flavedo de naranjas 'Navelate' (Cajuste y Lafuente, 2007). Por otro lado, datos recientes que indican que el incremento en la actividad fosfolipasa A (PLA), que se origina como consecuencia de la exposición de mandarinas 'Fallglo' y naranjas 'Navel' a cambios bruscos de humedad favorece el 'colapso de la corteza' (Alférez et al, 2008). Teniendo en cuenta que el aumento de ROS favorece la peroxidación de lípidos de membrana, el conjunto de estos resultados apoyan la idea de que el estrés oxidativo está implicado en el desarrollo y severidad de esta alteración fisiológica en los frutos cítricos.…”