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Article|01 Apr 2018|OPEN
Transcriptome profiling reveals regulatory mechanisms underlying corolla senescence in petunia
Hong Wang1,2, Xiaoxiao Chang3, Youhong Chang1, Jen-Chih Chen2,4, Michael S. Reid2, Cai-Zhong Jiang5,2, & Jing Lin1,
1Institute of Pomology/Jiangsu Key Laboratory for Horticultural Crop Genetic Improvement, Jiangsu Academy of Agricultural Sciences, 210014 Nanjing, China
2Department of Plant Sciences, University of California, Davis, Davis, CA 95616, USA
3Institute of Fruit Tree Research, Guangdong Academy of Agricultural Science 510640 Guangzhou, China
4Institute of Biotechnology, National Taiwan University, 10617 Taipei, Taiwan
5United States Department of Agriculture, Crops Pathology and Genetics Research Unit, Agricultural Research Service, Davis, CA 95616, USA

Horticulture Research 5,
Article number: 16 (2018)
doi: 10.1038/hortres.2018.16
Views: 639

Received: 20 Jul 2017
Revised: 09 Jan 2018
Accepted: 12 Jan 2018
Published online: 01 Apr 2018

Abstract

The genetic regulatory mechanisms that govern natural corolla senescence in petunia are not well understood. To identify key genes and pathways that regulate the process, we performed a transcriptome analysis in petunia corolla at four developmental stages, including corolla fully opening without anther dehiscence (D0), corolla expansion, 2 days after anthesis (D2), corolla with initial signs of senescence (D4), and wilting corolla (D7). We identified large numbers of differentially expressed genes (DEGs), ranging from 4626 between the transition from D0 and D2, 1116 between D2 and D4, a transition to the onset of flower senescence, and 327 between D4 and D7, a developmental stage representing flower senescence. KEGG analysis showed that the auxin- and ethylene-related hormone biosynthesis and signaling transduction pathways were significantly activated during the flower development and highly upregulated at onset of flower senescence. Ethylene emission was detected at the D2 to D4 transition, followed by a large eruption at the D4 to D7 transition. Furthermore, large numbers of transcription factors (TFs) were activated over the course of senescence. Functional analysis by virus-induced gene silencing (VIGS) experiments demonstrated that inhibition of the expression of TFs, such as ethylene-related ERF, auxin-related ARF, bHLH, HB, and MADS-box, significantly extended or shortened flower longevity. Our data suggest that hormonal interaction between auxin and ethylene may play critical regulatory roles in the onset of natural corolla senescence in petunia.