Articles
TRANSCRIPTOMIC RESPONSES OF ‘NAVELATE’ ORANGE (CITRUS SINENSIS L. OSBECK) FRUIT TO WATER STRESS
Article number
892_43
Pages
351 – 356
Language
English
Abstract
Moderate water stress may originate depressed areas in the peel of fruit from many citrus cultivars when stored at non-chilling temperatures. Navelate (Citrus sinensis L. Osbeck) orange fruit is prone to this physiological disorder known as rind breakdown or non-chilling peel pitting.
To analyze molecular responses to dehydration conditions in Navelate oranges, we performed a large-scale gene expression analysis of the transcriptomic changes in the flavedo of fruit stored for 1 and 3 weeks under conditions causing moderate water loss (70-75% RH and 12°C) that may result in non-chilling peel pitting.
Last generation of the cDNA microarray generated by the Spanish Citrus Functional Genomics Project containing more than 21,000 unigenes was used.
Weight loss continuously increased during fruit storage but the content of ABA in the flavedo increased twice during the first week and remained constant thereafter.
The number of differentially expressed genes reached a maximum (3540) by one week storage but sharply decreased (859) by three weeks of fruit dehydration.
Gene ontology analysis revealed that biological processes related to water deprivation and inorganic cation transport were induced, while lipid biosynthesis, organic acid and aromatic compound metabolism were repressed by one week.
In contrast, no differential biological processes were identified by three weeks.
Among genes belonging to induced processes, we identified key genes involved in the synthesis (NCED) and perception (protein phosphatases 2C) of ABA and others related to membrane homeostasis, such as aquaporins, metal transporters and vacuolar proton-pumps.
Interestingly, other phosphatases 2C were repressed.
It is also noteworthy the over-expression of genes participating in cell detoxification system after one week of fruit dehydration, suggesting an early response of flavedo cells to avoid cellular damage.
Collectively, the results evidence important roles of ABA, membrane permeability and antioxidant enzymes in dehydration-protective mechanisms of citrus fruit.
To analyze molecular responses to dehydration conditions in Navelate oranges, we performed a large-scale gene expression analysis of the transcriptomic changes in the flavedo of fruit stored for 1 and 3 weeks under conditions causing moderate water loss (70-75% RH and 12°C) that may result in non-chilling peel pitting.
Last generation of the cDNA microarray generated by the Spanish Citrus Functional Genomics Project containing more than 21,000 unigenes was used.
Weight loss continuously increased during fruit storage but the content of ABA in the flavedo increased twice during the first week and remained constant thereafter.
The number of differentially expressed genes reached a maximum (3540) by one week storage but sharply decreased (859) by three weeks of fruit dehydration.
Gene ontology analysis revealed that biological processes related to water deprivation and inorganic cation transport were induced, while lipid biosynthesis, organic acid and aromatic compound metabolism were repressed by one week.
In contrast, no differential biological processes were identified by three weeks.
Among genes belonging to induced processes, we identified key genes involved in the synthesis (NCED) and perception (protein phosphatases 2C) of ABA and others related to membrane homeostasis, such as aquaporins, metal transporters and vacuolar proton-pumps.
Interestingly, other phosphatases 2C were repressed.
It is also noteworthy the over-expression of genes participating in cell detoxification system after one week of fruit dehydration, suggesting an early response of flavedo cells to avoid cellular damage.
Collectively, the results evidence important roles of ABA, membrane permeability and antioxidant enzymes in dehydration-protective mechanisms of citrus fruit.
Authors
P. Romero, M.J. Rodrigo, F. Alférez, L. Zacarias, M.T. Lafuente
Keywords
citrus fruit, functional genomics, water stress, abscisic acid
Online Articles (48)