1Floriculture Research Institute, Yunnan Academy of Agricultural Sciences, National Engineering Research Center for Ornamental Horticulture, Key Laboratory for Flower Breeding of Yunnan Province, 650200, Kunming, China 2College of Agriculture and Biotechnology, Zhejiang University, 310030, Hangzhou, China 3Shenzhen Branch, Guangdong Laboratory of Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture and Rural Affairs, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, 518120, Shenzhen, China 4School of Agriculture, Yunnan University, 650504, Kunming, China 5Fujian Provincial Key Laboratory of Haixia Applied Plant Systems Biology, Fujian Agriculture and Forestry University, 350002, Fuzhou, China 6Key Laboratory of Horticultural Plant Biology, Ministry of Education, College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan 430070, Hubei Province, China 7National R&D Center for Citrus Postharvest Technology, College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan 430070, Hubei Province, China 8Hubei Hongshan Laboratory, Wuhan 430070, China 9These authors jointly supervised this work 10These authors contributed equally *Corresponding author. E-mail: lifan@yaas.org.cn,zls83@zju.edu.cn,wjh@yaas.org.cn
Received: 30 Mar 2022 Accepted: 02 Aug 2022 Published online: 24 Aug 2022
Abstract
Gypsophila paniculata, belonging to the Caryophyllaceae of the Caryophyllales, is one of the most famous worldwide cut flowers. It is commonly used as dried flowers, whereas the underlying mechanism of flower senescence has not yet been addressed. Here, we present a chromosome-scale genome assembly for G. paniculata with a total size of 749.58 Mb. Whole-genome duplication signatures unveil two major duplication events in its evolutionary history: an ancient one occurring before the divergence of Caryophyllaceae and a more recent one shared with Dianthus caryophyllus. The integrative analyses combining genomic and transcriptomic data reveal the mechanisms regulating floral development and ethylene response of G. paniculata. The reduction of AGAMOUS expression probably caused by sequence polymorphism and the mutation in miR172 binding site of PETALOSA are associated with the double flower formation in G. paniculata. The low expression of ETHYLENE RESPONSE SENSOR (ERS) and the reduction of downstream ETHYLENE RESPONSE FACTOR (ERF) gene copy number collectively lead to the ethylene insensitivity of G. paniculata, affecting flower senescence and making it capable of making dried flowers. This study provides a cornerstone for understanding the underlying principles governing floral development and flower senescence, which could accelerate the molecular breeding of the Caryophyllaceae species.