Overexpression of PSY1 increases fruit skin and flesh carotenoid content and reveals associated transcription factors in apple (Malus × domestica)
Knowledge of the transcriptional regulation of the carotenoid metabolic pathway is still emerging and here, we have misexpressed a key biosynthetic gene in apple to highlight potential transcriptional regulators of this pathway. We overexpressed phytoene synthase (PSY1), which controls the key rate-...
| Main Authors: | , , , , , , , , , |
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| Format: | Article |
| Language: | English |
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Frontiers Media S.A.
2022-09-01
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| Series: | Frontiers in Plant Science |
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| Online Access: | https://www.frontiersin.org/articles/10.3389/fpls.2022.967143/full |
| _version_ | 1798033874937184256 |
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| author | Charles Ampomah-Dwamena Sumathi Tomes Amali H. Thrimawithana Caitlin Elborough Caitlin Elborough Nitisha Bhargava Ria Rebstock Paul Sutherland Hilary Ireland Andrew C. Allan Richard V. Espley |
| author_facet | Charles Ampomah-Dwamena Sumathi Tomes Amali H. Thrimawithana Caitlin Elborough Caitlin Elborough Nitisha Bhargava Ria Rebstock Paul Sutherland Hilary Ireland Andrew C. Allan Richard V. Espley |
| author_sort | Charles Ampomah-Dwamena |
| collection | DOAJ |
| description | Knowledge of the transcriptional regulation of the carotenoid metabolic pathway is still emerging and here, we have misexpressed a key biosynthetic gene in apple to highlight potential transcriptional regulators of this pathway. We overexpressed phytoene synthase (PSY1), which controls the key rate-limiting biosynthetic step, in apple and analyzed its effects in transgenic fruit skin and flesh using two approaches. Firstly, the effects of PSY overexpression on carotenoid accumulation and gene expression was assessed in fruit at different development stages. Secondly, the effect of light exclusion on PSY1-induced fruit carotenoid accumulation was examined. PSY1 overexpression increased carotenoid content in transgenic fruit skin and flesh, with beta-carotene being the most prevalent carotenoid compound. Light exclusion by fruit bagging reduced carotenoid content overall, but carotenoid content was still higher in bagged PSY fruit than in bagged controls. In tissues overexpressing PSY1, plastids showed accelerated chloroplast to chromoplast transition as well as high fluorescence intensity, consistent with increased number of chromoplasts and carotenoid accumulation. Surprisingly, the expression of other carotenoid pathway genes was elevated in PSY fruit, suggesting a feed-forward regulation of carotenogenesis when this enzyme step is mis-expressed. Transcriptome profiling of fruit flesh identified differentially expressed transcription factors (TFs) that also were co-expressed with carotenoid pathway genes. A comparison of differentially expressed genes from both the developmental series and light exclusion treatment revealed six candidate TFs exhibiting strong correlation with carotenoid accumulation. This combination of physiological, transcriptomic and metabolite data sheds new light on plant carotenogenesis and TFs that may play a role in regulating apple carotenoid biosynthesis. |
| first_indexed | 2024-04-11T20:35:38Z |
| format | Article |
| id | doaj.art-ed02d77270f2415490acc38ee3684d79 |
| institution | Directory Open Access Journal |
| issn | 1664-462X |
| language | English |
| last_indexed | 2024-04-11T20:35:38Z |
| publishDate | 2022-09-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Plant Science |
| spelling | doaj.art-ed02d77270f2415490acc38ee3684d792022-12-22T04:04:22ZengFrontiers Media S.A.Frontiers in Plant Science1664-462X2022-09-011310.3389/fpls.2022.967143967143Overexpression of PSY1 increases fruit skin and flesh carotenoid content and reveals associated transcription factors in apple (Malus × domestica)Charles Ampomah-Dwamena0Sumathi Tomes1Amali H. Thrimawithana2Caitlin Elborough3Caitlin Elborough4Nitisha Bhargava5Ria Rebstock6Paul Sutherland7Hilary Ireland8Andrew C. Allan9Richard V. Espley10The New Zealand Institute for Plant and Food Research Ltd., Auckland, New ZealandThe New Zealand Institute for Plant and Food Research Ltd., Auckland, New ZealandThe New Zealand Institute for Plant and Food Research Ltd., Auckland, New ZealandThe New Zealand Institute for Plant and Food Research Ltd., Auckland, New ZealandBioLumic Limited, Palmerston North, New ZealandThe New Zealand Institute for Plant and Food Research Ltd., Auckland, New ZealandThe New Zealand Institute for Plant and Food Research Ltd., Auckland, New ZealandThe New Zealand Institute for Plant and Food Research Ltd., Auckland, New ZealandThe New Zealand Institute for Plant and Food Research Ltd., Auckland, New ZealandThe New Zealand Institute for Plant and Food Research Ltd., Auckland, New ZealandThe New Zealand Institute for Plant and Food Research Ltd., Auckland, New ZealandKnowledge of the transcriptional regulation of the carotenoid metabolic pathway is still emerging and here, we have misexpressed a key biosynthetic gene in apple to highlight potential transcriptional regulators of this pathway. We overexpressed phytoene synthase (PSY1), which controls the key rate-limiting biosynthetic step, in apple and analyzed its effects in transgenic fruit skin and flesh using two approaches. Firstly, the effects of PSY overexpression on carotenoid accumulation and gene expression was assessed in fruit at different development stages. Secondly, the effect of light exclusion on PSY1-induced fruit carotenoid accumulation was examined. PSY1 overexpression increased carotenoid content in transgenic fruit skin and flesh, with beta-carotene being the most prevalent carotenoid compound. Light exclusion by fruit bagging reduced carotenoid content overall, but carotenoid content was still higher in bagged PSY fruit than in bagged controls. In tissues overexpressing PSY1, plastids showed accelerated chloroplast to chromoplast transition as well as high fluorescence intensity, consistent with increased number of chromoplasts and carotenoid accumulation. Surprisingly, the expression of other carotenoid pathway genes was elevated in PSY fruit, suggesting a feed-forward regulation of carotenogenesis when this enzyme step is mis-expressed. Transcriptome profiling of fruit flesh identified differentially expressed transcription factors (TFs) that also were co-expressed with carotenoid pathway genes. A comparison of differentially expressed genes from both the developmental series and light exclusion treatment revealed six candidate TFs exhibiting strong correlation with carotenoid accumulation. This combination of physiological, transcriptomic and metabolite data sheds new light on plant carotenogenesis and TFs that may play a role in regulating apple carotenoid biosynthesis.https://www.frontiersin.org/articles/10.3389/fpls.2022.967143/fullcarotenoid biosynthesistransgenic appletranscriptomeplastidsgene expressionphytoene synthase |
| spellingShingle | Charles Ampomah-Dwamena Sumathi Tomes Amali H. Thrimawithana Caitlin Elborough Caitlin Elborough Nitisha Bhargava Ria Rebstock Paul Sutherland Hilary Ireland Andrew C. Allan Richard V. Espley Overexpression of PSY1 increases fruit skin and flesh carotenoid content and reveals associated transcription factors in apple (Malus × domestica) Frontiers in Plant Science carotenoid biosynthesis transgenic apple transcriptome plastids gene expression phytoene synthase |
| title | Overexpression of PSY1 increases fruit skin and flesh carotenoid content and reveals associated transcription factors in apple (Malus × domestica) |
| title_full | Overexpression of PSY1 increases fruit skin and flesh carotenoid content and reveals associated transcription factors in apple (Malus × domestica) |
| title_fullStr | Overexpression of PSY1 increases fruit skin and flesh carotenoid content and reveals associated transcription factors in apple (Malus × domestica) |
| title_full_unstemmed | Overexpression of PSY1 increases fruit skin and flesh carotenoid content and reveals associated transcription factors in apple (Malus × domestica) |
| title_short | Overexpression of PSY1 increases fruit skin and flesh carotenoid content and reveals associated transcription factors in apple (Malus × domestica) |
| title_sort | overexpression of psy1 increases fruit skin and flesh carotenoid content and reveals associated transcription factors in apple malus domestica |
| topic | carotenoid biosynthesis transgenic apple transcriptome plastids gene expression phytoene synthase |
| url | https://www.frontiersin.org/articles/10.3389/fpls.2022.967143/full |
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