Transcriptomics-based identification and characterization of glucosyltransferases involved in betalain biosynthesis in Hylocereus megalanthus

Fangfang Xie; Qingzhu Hua; Canbin Chen; Lulu Zhang; Zhike Zhang; Jianye Chen; Rong Zhang; Junsheng Zhao; Guibing Hu; Jietang Zhao; Yonghua Qin

doi:10.1016/j.plaphy.2020.04.023

Transcriptomics-based identification and characterization of glucosyltransferases involved in betalain biosynthesis in Hylocereus megalanthus

Plant Physiol Biochem. 2020 Apr 24:152:112-124. doi: 10.1016/j.plaphy.2020.04.023. Online ahead of print.

Authors

Affiliations

¹ State Key Laboratory for Conservation and Utilization of Subtropical Agrobioresources/Guangdong Provincial Key Laboratory of Postharvest Science of Fruits and Vegetables/Key Laboratory of South China Horticultural Crop Biology and Germplasm Enhancement, Ministry of Agriculture, College of Horticulture, South China Agricultural University, Guangzhou, 510642, China.
² Institute of Fruit Science in Maoming, Maoming, 525000, China.
³ State Key Laboratory for Conservation and Utilization of Subtropical Agrobioresources/Guangdong Provincial Key Laboratory of Postharvest Science of Fruits and Vegetables/Key Laboratory of South China Horticultural Crop Biology and Germplasm Enhancement, Ministry of Agriculture, College of Horticulture, South China Agricultural University, Guangzhou, 510642, China. Electronic address: qinyh@scau.edu.cn.

PMID: 32413806
DOI: 10.1016/j.plaphy.2020.04.023

Abstract

Pitaya (Hylocereus spp.) is the only commercial cultivation of fruit containing abundant betalains for consumer. Betalains are water-soluble nitrogen-containing pigments with high nutritional value and bioactivities. In this study, contents of betaxanthins and betacyanins were compared between 'Guanhuabai' (H. undatus) and 'Huanglong' (H. megalanthus) pitayas and key genes involved in betalain biosynthesis were screened from 'Huanglong' pitaya by RNA-Seq technology. Twenty-nine candidate genes related to betalain biosynthesis were obtained from the transcriptome data. Based on expression characteristics and sequence analyses, HmB5GT1 and HmHCGT2 were further analyzed. HmB5GT1 and HmHCGT2 were both conserved in 'PSPG-box' and localized in nucleus. Silencing of HmB5GT1 and HmHCGT2 resulted in a significant reduction in betacyanin and betaxanthin contents. Those results suggested that HmB5GT1 and HmHCGT2 are possibly involved in betalain biosynthesis in H. megalanthus. The present work provides new information on betalain biosynthesis in Hylocereus at the transcriptional level.

Keywords: Pitaya transcriptome analysis betalain biosynthesis glucosyltransferases.