Open Access

ARTICLE

Transcriptomic and Physiological Analyses of Pigment Accumulation in Eucommia ulmoides ‘Hongye’

Mengjiao Chen^1,2, Jinhui Zhai³, Jiajia Zhang^1,4,5,6, Hui Li^1,2, Xinjiang Niu^1,2, Yaxin Liu^1,2, Yue Ren^1,2, Hongyan Du^1,4,5,6, Jingle Zhu^1,4,5,6,*
1 Paulownia R&D Center, State Administration of Forestry and Grassland, Zhengzhou, 450003, China
2 College of Forestry, Henan Agricultural University, Zhengzhou, 450003, China
3 Department of Statistical and Actuarial Science, Western University, London, N6A 5B7, Canada
4 Non-Timber Forestry R&D Center, Chinese Academy of Forestry, Zhengzhou, 450003, China
5 Eucommia Engineering Research Center of State Forestry Administration, Zhengzhou, 450003, China
6 Key Laboratory of Non-Timber Forest Germplasm Enhancement and Utilization of State Forestry and Grassland Administration, Zhengzhou, 450003, China
* Corresponding Author: Jingle Zhu. Email:
(This article belongs to this Special Issue: Plant Ecophysiology: Recent Trends and Advancements)

Phyton-International Journal of Experimental Botany 2022, 91(5), 1027-1044. https://doi.org/10.32604/phyton.2022.019106

Received 03 September 2021; Accepted 27 October 2021; Issue published 24 January 2022

Abstract

Eucommia ulmoides ‘Hongye’ is a new ornamental variety of E. ulmoides with excellent red or purple foliage. We found that E. ulmoides ‘Hongye’ exhibited a gradual change from green to red colour under light conditions. However, the colouring mechanism in the leaves of E. ulmoides ‘Hongye’ remains unclear. In this study, we compared the pigment content and leaf colour index of E. ulmoides ‘Hongye’ at five stages with those of E. ulmoides ‘Xiaoye’, which was used as the control variety. The transcriptome sequencing data of the first-period (H1, green) and fifth-period (H5, red) leaves were also analysed and compared. The corresponding gene regulation in anthocyanin-related metabolic pathways was then analysed. Physiological results indicated that the contents of flavonoids and anthocyanins in red leaves (H5) were significantly higher than those in green leaves (H1), whereas the chlorophyll content in red leaves (H5) was lower than that in green leaves (H1). Moreover, the carotenoid content did not significantly differ between the two varieties. A transcriptome analysis identified 4240 differentially expressed genes (DEGs), and 20 of these genes were found to be involved in flavonoid and anthocyanin biosynthesis pathways. The results provide a reference for further study of the leaf colouration mechanism in E. ulmoides.

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Keywords

Eucommia ulmoides; leaf colouring; anthocyanin; transcriptomics; flavonoid biosynthesis

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