Molecular cloning and expression of squalene synthase and 2,3-oxidosqualene cyclase genes in persimmon (Diospyros kaki L.) fruits

Zhou, Chunhua; Zhao, Daqiu; Sheng, Yanle; Liang, Guohua; Tao, Jun

doi:10.1007/s11033-011-0841-z

Cited by 7 publications

(5 citation statements)

References 24 publications

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“…SgSQS has two transmembrane domains in the C-terminal region, which is consistent with the reported presence of SQSs in the ER membrane13, 14. SQS genes have been identified in many organisms, including algae 15 , yeast, animals and plants 16 .…”

Section: Discussionsupporting

confidence: 90%

Cloning and characterization of squalene synthase and cycloartenol synthase from Siraitia grosvenorii

Zhao

Tang

et al. 2017

Acta Pharmaceutica Sinica B

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Mogrosides and steroid saponins are tetracyclic triterpenoids found in Siraitia grosvenorii. Squalene synthase (SQS) and cycloartenol synthase (CAS) are key enzymes in triterpenoid and steroid biosynthesis. In this study, full-length cDNAs of SgSQS and SgCAS were cloned by a rapid amplification of cDNA-ends with polymerase chain reaction (RACE-PCR) approach. The SgSQS cDNA has a 1254 bp open reading frame (ORF) encoding 417 amino acids, and the SgCAS cDNA contains a 2298 bp ORF encoding 765 amino acids. Bioinformatic analysis showed that the deduced SgSQS protein has two transmembrane regions in the C-terminal. Both SgSQS and SgCAS have significantly higher levels in fruits than in other tissues, suggesting that steroids and mogrosides are competitors for the same precursors in fruits. Combined in silico prediction and subcellular localization, experiments in tobacco indicated that SgSQS was probably in the cytoplasm or on the cytoskeleton, and SgCAS was likely located in the nucleus or cytosol. These results will provide a foundation for further study of SgSQS and SgCAS gene functions in S. grosvenorii, and may facilitate improvements in mogroside content in fruit by regulating gene expression.

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Section: Discussionsupporting

confidence: 90%

Cloning and characterization of squalene synthase and cycloartenol synthase from Siraitia grosvenorii

Zhao

Tang

et al. 2017

Acta Pharmaceutica Sinica B

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“…In the case of other fruits, a diminution of SQS transcript levels has been described during the development and ripening of persimmon fruit. 47 In olive, the higher expression level detected for OeSQS2 in 'Picual' mesocarp is in line with the higher squalene content observed for this cultivar compared to 'Arbequina'. This result, together with the fact that this gene showed the highest transcript level of olive SQS genes in the mesocarp tissue, indicates that OeSQS2 seems to be the gene that mainly contributes to the biosynthesis of squalene in the olive mesocarp.…”

Section: Variability Of the Squalene Content In An Olivesupporting

confidence: 56%

“…All of these data point out that in olive fruit, the expression of SQS genes seems to be temporally regulated during the developmental and ripening period. In the case of other fruits, a diminution of SQS transcript levels has been described during the development and ripening of persimmon fruit …”

Section: Resultsmentioning

confidence: 99%

Functional Characterization of Four Olive Squalene Synthases with Respect to the Squalene Content of the Virgin Olive Oil

Hernández,

Muñoz-Ocaña,

Posada

et al. 2023

J. Agric. Food Chem.

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The release of new olive cultivars with an increased squalene content in their virgin olive oil is considered an important target in olive breeding programs. In this work, the variability of the squalene content in a core collection of 36 olive cultivars was first studied, revealing two olive cultivars, 'Dokkar' and 'Klon-14', with extremely low and high squalene contents in their oils, respectively. Next, four cDNA sequences encoding squalene synthases (SQS) were cloned from olive. Sequence analysis and functional expression in bacteria confirmed that they encode squalene synthases. Transcriptional analysis in distinct olive tissues and cultivars indicated that expression levels of these four SQS genes are spatially and temporally regulated in a cultivar-dependent manner and pointed to OeSQS2 as the gene mainly involved in squalene biosynthesis in olive mesocarp and, therefore, in the olive oil. In addition, the biosynthesis of squalene appears to be transcriptionally regulated in water-stressed olive mesocarp.

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“…Quantitative analysis of the triterpenoid content in neem (Azadirachta indica) indicated that there was tissue-specific variation in terms of abundance (Pandreka et al, 2015). Oleanolic acid (OA) and ursolic acid (UA), the main triterpene acids in persimmon fruit, changed during fruit development (Zhou et al, 2012). Limonin and nomilin, as the predominant limonoids in a group of chemically related triterpene derivatives in the Rutaceae and Meliaceae plant families, increased at first and then gradually decreased in some citrus species during growth and maturation when the limomoid UDP-glucosyltransferase regulated the conversion of limonoid to glucoside (Kita et al, 2000).…”

Section: Discussionmentioning

confidence: 99%

Change in Bitterness, Accumulation of Cucurbitacin B and Expression Patterns of CuB Biosynthesis-related Genes in Melon During Fruit Development

Dai

Liu

et al. 2019

Hortic J

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Bitterness, caused by cucurbitacins, is present in some melon fruit. Although bitter compound biosynthesis and regulation in Cucurbitaceae plants have been reported, the dynamic changes in bitterness during fruit development are unknown. Bitterness severity was measured for 19 inbred melon lines, including 14 lines of Cucumis melo var. chinensis, two var. inodorus and three var. conomon, using a panel tasting method. The data showed that bitterness severity was different in several lines of var. chinensis during fruit growth and maturation. Nb46 and Nb320, two elite parental lines of var. chinensis used in melon breeding, were used as experimental materials. Bitterness was severe at stage I, but moderate and disappeared at stage II and III in the fruit of Nb46. There was non-bitterness in the fruit of Nb320 throughout the development period. Furthermore, the cucurbitacin B (CuB) content gradually decreased in Nb46, while in Nb320, the CuB content changed little and remained at a quite low level during fruit development. Different expression patterns of the genes involved in CuB biosynthesis and regulation were found between Nb46 and Nb320. The expression levels of these genes were significantly higher in Nb46 than Nb320 in the early developmental stages, and this correlated with a higher concentration of CuB in Nb46 than Nb320. These results demonstrate that bitterness severity is different in var. chinensis during fruit developmental stages, and that the CuB biosynthesis-related genes are a critical factor in this process. We hope these findings will contribute to the breeding of non-bitter melon cultivars.

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Molecular cloning and expression of squalene synthase and 2,3-oxidosqualene cyclase genes in persimmon (Diospyros kaki L.) fruits

Cited by 7 publications

References 24 publications

Cloning and characterization of squalene synthase and cycloartenol synthase from Siraitia grosvenorii

Cloning and characterization of squalene synthase and cycloartenol synthase from Siraitia grosvenorii

Functional Characterization of Four Olive Squalene Synthases with Respect to the Squalene Content of the Virgin Olive Oil

Change in Bitterness, Accumulation of Cucurbitacin B and Expression Patterns of CuB Biosynthesis-related Genes in Melon During Fruit Development

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