Regulation of carotenoid accumulation and the expression of carotenoid metabolic genes in citrus juice sacs in vitro

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

Molecular characterization of a flavanone 3-hydroxylase gene from citrus fruit reveals its crucial roles in anthocyanin accumulation

Abstract Background Flavanone 3-hydroxylase (F3H), a key enzyme in the flavonoid biosynthetic pathway, plays an important role in the regulation of flavonols and anthocyanidins accumulation. Citrus fruit is a rich source of flavonoids with varied flavonoid compositions among different varieties. To date, the study on F3H is limited in citrus, and its roles in regulating flavonoid accumulation in citrus fruit are still unclear. Results In this study, we isolated a CitF3H from three different citrus varieties, Satsuma mandarin (Citrus unshiu Marc.), Ponkan mandarin (C. reticulata Blanco) and blood orange ‘Moro’ (C. sinensis Osbeck). Functional analysis showed that CitF3H encoded a functional flavanone 3-hydroxylase. It catalyzed the hydroxylation of naringenin to yield dihydrokaempferol, which was a precursor of anthocyanins in flavonoid biosynthetic pathway. In the juice sacs, CitF3H was differentially expressed among the three citrus varieties, and its expression level was positively correlated with the accumulation of anthocyanins during the ripening process. In the juice sacs of Satsuma mandarin and Ponkan mandarin the expression of CitF3H kept constant at an extremely low level, and no anthocyanin was accumulated during the ripening process. In contrast, the expression of CitF3H increased rapidly along with the accumulation of anthocyanin in the juice sacs of blood orange ‘Moro’ during the ripening process. In addition, we found that blue light irradiation was effective to up-regulate the expression of CitF3H and improve anthocyanin accumulation in the juice sacs of blood orange ‘Moro’ in vitro. Conclusion CitF3H was a key gene regulating anthocyanin accumulation in the juice sacs of citrus fruit. The results presented in this study will contribute to elucidating anthocyanin biosynthesis in citrus fruit, and provide new strategies to improve the nutritional and commercial values of citrus fruit

Identification and quantitative analysis of β-cryptoxanthin and β-citraurin esters in Satsuma mandarin fruit during the ripening process

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Effect of the combination of ethylene and red LED light irradiation on carotenoid accumulation and carotenogenic gene expression in the flavedo of citrus fruit

NOTICE: this is the author’s version of a work that was accepted for publication in Postharvest Biology and Technology. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Postharvest Biology and Technology, Vol 99, January 2015, DOI: 10.1016/j.postharvbio.2014.08.002autho

Exogenous gibberellin induced regreening through the regulation of chlorophyll and carotenoid metabolism in Valencia oranges

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Regulation of ascorbic acid metabolism by blue LED light irradiation in citrus juice sacs

NOTICE: this is the author’s version of a work that was accepted for publication in Plant Science. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Plant Science, Volume 233, April 2015, doi:10.1016/j.plantsci.2015.01.010autho

Effect of 1-Methylcyclopropene on the Expression of Genes for Ascorbate Metabolism in Postharvest Cauliflower

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THE USE OF PUPPET AND PICTURE IN TEACHING VOCABULARY FOR ELEMENTARY SCHOOL STUDENTS

AbstractName: Syaiful HalimStudent Number: 0706102020049Study Program: English EducationTitle: The use of Puppet and Picture in Teaching vocabulary for Elementary School Students(A Library Research)In Indonesia, vocabulary one of materials that students have to master. Hence, some elementary school, there are some students still have lack of motivation in mastering the vocabulary especially in rural area. The objective of this study is to find out whether teaching by using puppet and picture assist the young learners, especially in learning vocabulary. This study is carried out by using a library research. This study is with references findings and related theories on how puppet and picture effective for vocabulary mastery. The result of the discussion found that teaching by using puppet and picture assist students in learning vocabulary. Since the students are easier to remember the vocabularies, English teachers strongly recommend to use puppet and picture for young learners because these media can motivate them and make them interested in English