Genetic and chemical characterization of an EMS induced mutation in Cucumis melo CRTISO gene

Galpaz, Navot; Burger, Yosi; Lavee, Tamar; Tzuri, Galil; Sherman, Amir; Melamed, Tal; Eshed, Ravit; Meir, Ayala; Portnoy, Vitaly; Bar, Einat; Shimoni-Shor, Einav; Feder, Ari; Saar, Yuval; Saar, Uzi; Baumkoler, Fabian; Lewinsohn, Efraim; Schaffer, Arthur A.; Katzir, Nurit; Tadmor, Yaakov

doi:10.1016/j.abb.2013.08.006

Cited by 52 publications

(56 citation statements)

References 42 publications

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“…This line exhibits a dysfunctional crtiso due to a premature stop codon, which prevents carotenoid isomerization in the fruit flesh and causes the accumulation of light yellow prolycopene (Galpaz et al, 2013). The prolycopene amounts in a CRTISO-deficient background would indicate pathway flux without the impact of further metabolism of b-carotene, similar to the chemical inhibition of carotenoid biosynthesis performed so far.…”

Section: Cmor-lowb Reduces the Metabolic Flux In Developing Fruits Ofmentioning

confidence: 98%

“…5C; Supplemental Table S2). Since yofi accumulates prolycopene in the female flower ovules (Galpaz et al, 2013), we also examined the color of transected female flowers at the day of anthesis.…”

Section: Cmor-lowb Reduces the Metabolic Flux In Developing Fruits Ofmentioning

confidence: 99%

“…To further study the molecular role of CmOr in melon fruit, we screened M2 families of the previously described orange-fleshed CEZ-based EMS library for fruit color changes (Tadmor et al, 2007;Galpaz et al, 2013). Twelve plants from each of 1,000 M2 families were grown in the field, and the mature fruit were phenotyped visually.…”

Section: Isolation Of An Ems-induced Low-b Mutant and Its Fruit Phenomentioning

confidence: 99%

“…These isomerizations yield all-trans-lycopene, the substrate for lycopene b-and «-ring cyclases (Isaacson et al, 2002). CRTISO deficiency results in an arrest of pathway flux in tissues without a functional photosynthetic apparatus; for instance, CRTISO mutant tomato (Solanum lycopersicum) or melon fruits accumulate mainly prolycopene (Isaacson et al, 2002;Galpaz et al, 2013).…”

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confidence: 99%

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Distinct Mechanisms of the ORANGE Protein in Controlling Carotenoid Flux

Chayut

Yuan

Ohali³

et al. 2016

Plant Physiol.

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106

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b-Carotene adds nutritious value and determines the color of many fruits, including melon (Cucumis melo). In melon mesocarp, b-carotene accumulation is governed by the Orange gene (CmOr) golden single-nucleotide polymorphism (SNP) through a yet to be discovered mechanism. In Arabidopsis (Arabidopsis thaliana), OR increases carotenoid levels by posttranscriptionally regulating phytoene synthase (PSY). Here, we identified a CmOr nonsense mutation (Cmor-lowb) that lowered fruit b-carotene levels with impaired chromoplast biogenesis. Cmor-lowb exerted a minimal effect on PSY transcripts but dramatically decreased PSY protein levels and enzymatic activity, leading to reduced carotenoid metabolic flux and accumulation. However, the golden SNP was discovered to not affect PSY protein levels and carotenoid metabolic flux in melon fruit, as shown by carotenoid and immunoblot analyses of selected melon genotypes and by using chemical pathway inhibitors. The high b-carotene accumulation in golden SNP melons was found to be due to a reduced further metabolism of b-carotene. This was revealed by genetic studies with double mutants including carotenoid isomerase (yofi), a carotenoid-isomerase nonsense mutant, which arrests the turnover of prolycopene. The yofi F2 segregants accumulated prolycopene independently of the golden SNP. Moreover, Cmor-lowb was found to inhibit chromoplast formation and chloroplast disintegration in fruits from 30 d after anthesis until ripening, suggesting that CmOr regulates the chloroplast-to-chromoplast transition. Taken together, our results demonstrate that CmOr is required to achieve PSY protein levels to maintain carotenoid biosynthesis metabolic flux but that the mechanism of the CmOr golden SNP involves an inhibited metabolism downstream of b-carotene to dramatically affect both carotenoid content and plastid fate.b-Carotene, a C-40 isoprenoid molecule, is the major source of vitamin A in the human diet (Maiani et al., 2009). Lack of dietary vitamin A is a common cause of premature death and child blindness in developing countries. b-Carotene is abundant in diverse edible plant tissues such as pumpkin (Cucurbita pepo) fruits, sweet potato (Ipomoea batatas) tubers, carrot (Daucus carota) roots, kale (Brassica oleracea) leaves, mango (Mangifera indica), and orange-fleshed melon (Cucumis melo) fruits (Howitt and Pogson, 2006;Yuan et al., 2015b). In green tissues, two b-carotene molecules are located in each PSII reaction center to facilitate electron transfer and to provide photoprotection by quenching singlet oxygen products (Telfer, 2002). In many fruits and flowers, b-carotene serves as a yellow-orange colorant and as a precursor for aromatic molecules to attract pollinators and seed dispersers (Walter and Strack, 2011).b-Carotene is a metabolite in the carotenoid biosynthesis pathway that receives its precursors from the plastid-localized methyl-erythritol phosphate pathway. Carotenoid biosynthesis starts with the condensation of two geranylgeranyl diphosphate molecules, yielding the color...

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Section: Cmor-lowb Reduces the Metabolic Flux In Developing Fruits Ofmentioning

confidence: 98%

Section: Cmor-lowb Reduces the Metabolic Flux In Developing Fruits Ofmentioning

confidence: 99%

Section: Isolation Of An Ems-induced Low-b Mutant and Its Fruit Phenomentioning

confidence: 99%

mentioning

confidence: 99%

See 2 more Smart Citations

Distinct Mechanisms of the ORANGE Protein in Controlling Carotenoid Flux

Chayut

Yuan

Ohali³

et al. 2016

Plant Physiol.

Self Cite

106

109

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show abstract

“…S11), its involvement in the posttranscriptional down-regulation of AtPSY appears unlikely. However, additional, hitherto unidentified carotenoid-derived metabolites with signaling function have been reported as being involved in the feedback regulation of carotenogenic gene expression (Diretto et al, 2006;Bai et al, 2009;Kachanovsky et al, 2012;Galpaz et al, 2013) and in the control of developmental processes (Avendaño-Vázquez et al, 2014;Van Norman et al, 2014;Tian, 2015). Furthermore, altered carotenoid patterns, achieved by overexpressing a downstream carotene hydroxylase, reduced PSY protein amounts in cultivated carrots by a posttranscriptional mechanism (Arango et al, 2014).…”

Section: Flux-dependent Translational Control Of Psy Mediated By the mentioning

confidence: 99%

Carotenogenesis Is Regulated by 5′UTR-Mediated Translation of Phytoene Synthase Splice Variants

et al. 2016

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Phytoene synthase (PSY) catalyzes the highly regulated, frequently rate-limiting synthesis of the first biosynthetically formed carotene. While PSY constitutes a small gene family in most plant taxa, the Brassicaceae, including Arabidopsis (Arabidopsis thaliana), predominantly possess a single PSY gene. This monogenic situation is compensated by the differential expression of two alternative splice variants (ASV), which differ in length and in the exon/intron retention of their 59UTRs. ASV1 contains a long 59UTR (untranslated region) and is involved in developmentally regulated carotenoid formation, such as during deetiolation. ASV2 contains a short 59UTR and is preferentially induced when an immediate increase in the carotenoid pathway flux is required, such as under salt stress or upon sudden light intensity changes. We show that the long 59UTR of ASV1 is capable of attenuating the translational activity in response to high carotenoid pathway fluxes. This function resides in a defined 59UTR stretch with two predicted interconvertible RNA conformations, as known from riboswitches, which might act as a flux sensor. The translation-inhibitory structure is absent from the short 59UTR of ASV2 allowing to bypass translational inhibition under conditions requiring rapidly increased pathway fluxes. The mechanism is not found in the rice (Oryza sativa) PSY1 59UTR, consistent with the prevalence of transcriptional control mechanisms in taxa with multiple PSY genes. The translational control mechanism identified is interpreted in terms of flux adjustments needed in response to retrograde signals stemming from intermediates of the plastid-localized carotenoid biosynthesis pathway.

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Biosynthesis and metabolism

Rodriguez–Amaya

2015

Food Carotenoids

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Genetic and chemical characterization of an EMS induced mutation in Cucumis melo CRTISO gene

Cited by 52 publications

References 42 publications

Distinct Mechanisms of the ORANGE Protein in Controlling Carotenoid Flux

Distinct Mechanisms of the ORANGE Protein in Controlling Carotenoid Flux

Carotenogenesis Is Regulated by 5′UTR-Mediated Translation of Phytoene Synthase Splice Variants

Biosynthesis and metabolism

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