Regulation of carotenoid accumulation and the expression of carotenoid metabolic genes in citrus juice sacs in vitro
Open Access
- 11 October 2011
- journal article
- research article
- Published by Oxford University Press (OUP) in Journal of Experimental Botany
- Vol. 63 (2), 871-886
- https://doi.org/10.1093/jxb/err318
Abstract
In the present study, to investigate the mechanisms regulating carotenoid accumulation in citrus, a culture system was set up in vitro with juice sacs of three citrus varieties, Satsuma mandarin (Citrus unshiu Marc.), Valencia orange (Citrus sinensis Osbeck), and Lisbon lemon (Citrus limon Burm.f.). The juice sacs of all the three varieties enlarged gradually with carotenoid accumulation. The changing patterns of carotenoid content and the expression of carotenoid metabolic genes in juice sacs in vitro were similar to those ripening on trees in the three varieties. Using this system, the changes in the carotenoid content and the expression of carotenoid metabolic genes in response to environmental stimuli were investigated. The results showed that carotenoid accumulation was induced by blue light treatment, but was not affected by red light treatment in the three varieties. Different regulation of CitPSY expression, which was up-regulated by blue light while unaffected by red light, led to different changes in carotenoid content in response to these two treatments in Satsuma mandarin and Valencia orange. In all three varieties, increases in carotenoid content were observed with sucrose and mannitol treatments. However, the accumulation of carotenoid in the two treatments was regulated by distinct mechanisms at the transcriptional level. With abscisic acid (ABA) treatment, the expression of the genes investigated in this study was up-regulated in Satsuma mandarin and Lisbon lemon, indicating that ABA induced its own biosynthesis at the transcriptional level. This feedback regulation of ABA led to decreases in carotenoid content. With gibberellin (GA) treatment, carotenoid content was significantly decreased in the three varieties. Changes in the expression of genes related to carotenoid metabolism varied among the three varieties in response to GA treatment. These results provided insights into improving carotenoid content and composition in citrus during fruit maturation.Keywords
This publication has 49 references indexed in Scilit:
- Source to sink: regulation of carotenoid biosynthesis in plantsTrends in Plant Science, 2010
- Effect of Postharvest Temperature and Ethylene on Carotenoid Accumulation in the Flavedo and Juice Sacs of Satsuma Mandarin (Citrus unshiu Marc.) FruitJournal of Agricultural and Food Chemistry, 2009
- Molecular and functional characterization of a novel chromoplast-specific lycopene β-cyclase from Citrus and its relation to lycopene accumulationJournal of Experimental Botany, 2009
- Regulation of carotenoid biosynthesis during fruit maturation in the red-fleshed orange mutant Cara CaraPhytochemistry, 2008
- Accumulation of Carotenoids and Expression of Carotenoid Biosynthetic Genes and Carotenoid Cleavage Dioxygenase Genes during Fruit Maturation in the Juice Sacs of ‘Tamami,’ ‘Kiyomi’ Tangor, and ‘Wilking’ MandarinJournal of the Japanese Society for Horticultural Science, 2007
- Sucrose deficiency delays lycopene accumulation in tomato fruit pericarp discsPlant Molecular Biology, 2006
- A novel approach of LED light radiation improves the antioxidant activity of pea seedlingsFood Chemistry, 2006
- Singlet oxygen and photo‐oxidative stress management in plants and algaePlant, Cell & Environment, 2005
- A Genome-Wide Analysis of the Effects of Sucrose on Gene Expression in Arabidopsis Seedlings under AnoxiaPlant Physiology, 2005
- Functional Analysis of the Early Steps of Carotenoid Biosynthesis in TobaccoPlant Physiology, 2002