CDNA Cloning and Expression Analysis of the Chalcone Synthases (CHS) in &amp;lt;i&amp;gt;Osmanthus fragrans&amp;lt;/i&amp;gt;

Yan Ma,Jing Guo,Ningning Zhang,Xiurong Xu,Dekui Zang

doi:10.4236/ajmb.2017.71004

CDNA Cloning and Expression Analysis of the Chalcone Synthases (CHS) in &lt;i&gt;Osmanthus fragrans&lt;/i&gt;

Yan Ma, Jing Guo + Show 3 more

Open Access

https://doi.org/10.4236/ajmb.2017.71004

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Abstract

In the flavonoid biosynthesis pathway, Chalcone synthase (CHS) is involved in the formation of the pigment and has been shown to be a rate-limiting enzyme for the synthesis of flavonoids. In this study, a PCR approach was used to clone a Chalcone synthases cDNA from flower of sweet osmanthus “Chenghong Dangui” and it was designated as OfCHS (O. fragrans, CHS). The cDNA was 1383 bp long and a coding sequence (CDS) of 1173 bp encoding a polypeptide of 391 amino acids with an estimated molecular mass of 39.9 kDa. The theoretical isoelectric point was 6.23. Phylogenetic analysis demonstrated that OfCHS clustered with Olea europaea, Solenostemon scutellarioides, Perilla frutescens, Antirrhinum majus and Digitalis lanata. We also detected the expression of OfCHS in different tissues in “Dangui” and in two cultivars with varied coloration, “Zi Yingui” and “Chenghong Dangui” at different floral stages using quantitative real-time PCR. We observed that OfCHS transcript was higher in leaves than in petals in “Dangui”. The transcripts of OfCHS in “Zi Yingui” petals were higher than those in “Dangui” at three stages especially at xianyan stage and there was no significant difference between the two cultivars in the full flowering stage. “Chenghong Dangui” has a relatively high anthocyanin content compared to “Zi Yingui”. The relative amount of anthocyanin of “Chenghong Dangui” initially increases, and then decreases during the bloom period. However, the expression of CHS is the highest at the initial flowering stage. These data suggest that the OfCHS does not play a key role in the accumulation of total flavonoid in this cultivar. These data could contribute to explain the different accumulation of flavonoids in petals of the two cultivars.

Highlights

IntroductionFlower color is one of the most important characters of ornamental plants, and directly
The cDNA was 1383 bp long and a coding sequence (CDS) of 1173 bp encoding a polypeptide of 391 amino acids with an estimated molecular mass of 39.9 kDa
The transcripts of OfCHS in “Zi Yingui” petals were higher than those in “Dangui” at three stages especially at xianyan stage and there was no significant difference between the two cultivars in the full flowering stage

Summary

Introduction

Flower color is one of the most important characters of ornamental plants, and directly. Y. Ma et al 42 affects the ornamental value and economic value; creating with novelty colors has been the pursuit of plant breeders. Flavonoids are synthesized via the phenylpropanoid and polyketide pathway, which starts with the condensation of one molecule of CoA-ester of cinnamic acid or derivatives such as coumaric or ferulic acid, and three molecules of malonyl-CoA, yielding a naringen in chalcone as major product. Chalcone synthases (CHSs), the most well known representatives of this family, provide the starting materials for a diverse set of metabolites (flavonoids) which have different and important roles in providing floral pigments, auxin protection and transport and stress resistance [4] [5] [6] [7]

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