Get 20M+ Full-Text Papers For Less Than $1.50/day. Start a 14-Day Trial for You or Your Team.

Learn More →

The molecular and biochemical basis for varietal variation in sesquiterpene content in melon (Cucumis melo L.) rinds

The molecular and biochemical basis for varietal variation in sesquiterpene content in melon... A combined chemical, biochemical and molecular study was conducted to understand the differential accumulation of volatile sesquiterpenes in melon fruits. Sesquiterpenes were present mainly in the rinds of climacteric varieties, and a great diversity in their composition was found among varieties. Sesquiterpenes were generally absent in non-climacteric varieties. Two climacteric melon varieties, the green-fleshed ‘Noy Yizre'el’, and the orange-fleshed ‘Dulce’ were further examined. In ‘Noy Yizre'el’ the main sesquiterpenes accumulated are δ-cadinene, γ-cadinene and α-copaene, while α-farnesene is the main sesquiterpene in ‘Dulce’. Sesquiterpene synthase activities, mainly restricted to rinds of mature fruits, were shown to generate different sesquiterpenes in each variety according to the compositions found in rinds. EST melon database mining yielded two novel cDNAs coding for members of the Tps gene family termed CmTpsNY and CmTpsDul respectively, that are 43.2% similar. Heterologous expression in E. coli of CmTpsNY produced mainly δ-copaene, α-copaene, β-caryophyllene, germacrene D, α-muurolene, γ-cadinene, δ-cadinene, and α-cadinene, while CmTpsDul produced α-farnesene only. CmTpsNY was mostly expressed in ‘Noy Yizre'el’ rind while CmTpsDul expression was specific to ’Dulce’ rind. None of these genes was expressed in rinds of the non-climacteric ‘Tam Dew’ cultivar. Our results indicate that different sesquiterpene synthases encoded by different members of the Tps gene family are active in melon varieties and this specificity modulates the accumulation of sesquiterpenes. The genes are differentially transcriptionally regulated during fruit development and according to variety and are likely to be associated with chemical differences responsible for the unique aromas of melon varieties. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Plant Molecular Biology Springer Journals

The molecular and biochemical basis for varietal variation in sesquiterpene content in melon (Cucumis melo L.) rinds

Loading next page...
1
 
/lp/springer_journal/the-molecular-and-biochemical-basis-for-varietal-variation-in-qfpLvYcV9V

References (63)

Publisher
Springer Journals
Copyright
Copyright © 2008 by Springer Science+Business Media B.V.
Subject
Life Sciences; Plant Pathology; Biochemistry, general; Plant Sciences
ISSN
0167-4412
eISSN
1573-5028
DOI
10.1007/s11103-008-9296-6
pmid
18264780
Publisher site
See Article on Publisher Site

Abstract

A combined chemical, biochemical and molecular study was conducted to understand the differential accumulation of volatile sesquiterpenes in melon fruits. Sesquiterpenes were present mainly in the rinds of climacteric varieties, and a great diversity in their composition was found among varieties. Sesquiterpenes were generally absent in non-climacteric varieties. Two climacteric melon varieties, the green-fleshed ‘Noy Yizre'el’, and the orange-fleshed ‘Dulce’ were further examined. In ‘Noy Yizre'el’ the main sesquiterpenes accumulated are δ-cadinene, γ-cadinene and α-copaene, while α-farnesene is the main sesquiterpene in ‘Dulce’. Sesquiterpene synthase activities, mainly restricted to rinds of mature fruits, were shown to generate different sesquiterpenes in each variety according to the compositions found in rinds. EST melon database mining yielded two novel cDNAs coding for members of the Tps gene family termed CmTpsNY and CmTpsDul respectively, that are 43.2% similar. Heterologous expression in E. coli of CmTpsNY produced mainly δ-copaene, α-copaene, β-caryophyllene, germacrene D, α-muurolene, γ-cadinene, δ-cadinene, and α-cadinene, while CmTpsDul produced α-farnesene only. CmTpsNY was mostly expressed in ‘Noy Yizre'el’ rind while CmTpsDul expression was specific to ’Dulce’ rind. None of these genes was expressed in rinds of the non-climacteric ‘Tam Dew’ cultivar. Our results indicate that different sesquiterpene synthases encoded by different members of the Tps gene family are active in melon varieties and this specificity modulates the accumulation of sesquiterpenes. The genes are differentially transcriptionally regulated during fruit development and according to variety and are likely to be associated with chemical differences responsible for the unique aromas of melon varieties.

Journal

Plant Molecular BiologySpringer Journals

Published: Feb 9, 2008

There are no references for this article.