Elucidating the mechanisms controlling the carotenoid retention trait in Capsicum annuum. / Holden, Alexandra.

2019. 302 p.

Research output: ThesisDoctoral Thesis

Unpublished

Documents

  • Alexandra Holden 2019 PhD Thesis

    Other version, 11.1 MB, PDF document

    Embargo ends: 18/11/21

  • Supplementary Table 1_DH population fresh fruit carotenoid screen

    Other version, 99.9 KB, application/vnd.openxmlformats-officedocument.spreadsheetml.sheet

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  • Supplementary Table 2_DH population stored fruit carotenoid screen

    Other version, 99.3 KB, application/vnd.openxmlformats-officedocument.spreadsheetml.sheet

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  • Supplementary Table 3_DH population carotenoid retention screen

    Other version, 184 KB, application/vnd.openxmlformats-officedocument.spreadsheetml.sheet

    Embargo ends: 18/11/21

  • Supplementary Table 4_DH population fresh fruit GCMS screen

    Other version, 323 KB, application/vnd.openxmlformats-officedocument.spreadsheetml.sheet

    Embargo ends: 18/11/21

  • Supplementary Table 5_DH subpopulation GCMS analysis

    Other version, 70.7 KB, application/vnd.openxmlformats-officedocument.spreadsheetml.sheet

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  • Supplementary Table 6_Low_vs_High retention cuticle RNAseq_differentially expressed genes

    Other version, 743 KB, application/vnd.openxmlformats-officedocument.spreadsheetml.sheet

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  • Supplementary Table 7_Low_vs_High retention RNAseq_differentially expressed genes

    Other version, 473 KB, application/vnd.openxmlformats-officedocument.spreadsheetml.sheet

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Abstract

Fruit colour is a key quality trait in chilli pepper (Capsicum annuum), and carotenoids are the major pigments responsible for conferring the red colour observed in pepper fruits. Carotenoids have valuable antioxidant properties. Post-harvest storage of peppers is often required in order for consumer demand to be met, and therefore peppers must retain their quality during storage. An understanding of changes in carotenoid content is essential for high quality carotenoid retaining lines to be bred.
In the present study, the mechanisms underlying the carotenoid retention trait have been investigated. Biochemical profiling, employing both HPLC-PDA and GC-MS has revealed changes in carotenoid content in the fruit of a Doubled Haploid population (375 associated lines), and has revealed that the carotenoid retention trait and intermediary metabolism are not linked. Physiological analysis of fruits has revealed the role of the fruit cuticle in controlling the carotenoid retention phenotype. The fruit cuticle protects fruit from carotenoid degradation by acting as a barrier to harmful oxidative species, which can result in non-enzymatic carotenoid cleavage. Transcriptomic analyses have resulted in the identification of candidate genes underlying the carotenoid retention trait, and a method of Virus Induced Gene Silencing (VIGS) has been established in pepper fruit for functional characterisation of genes, and validated in tomato.
This study sheds light on a previously understudied trait. Understanding the mechanisms underlying carotenoid retention in chilli pepper will not only result in breeding of improved pepper varieties, but this information may also be translated to other crops, which also experience costly post-harvest carotenoid degradation, and consequently, reduced antioxidant properties and nutritional content.
Original languageEnglish
QualificationPh.D.
Awarding Institution
Supervisors/Advisors
Thesis sponsors
  • BBSRC/Syngenta Ltd
Award date1 Dec 2019
Publication statusUnpublished - 18 Nov 2019

ID: 35091938