title: Spatial and temporal transcriptome changes occurring during flower opening and senescence of the ephemeral hibiscus flower, Hibiscus rosa-sinensis.
abstract: Flowers are complex systems whose vegetative and sexual structures initiate and die in a synchronous manner. The rapidity of this process varies widely in flowers, with some lasting for months while others such as Hibiscus rosa-sinensis survive for only a day. The genetic regulation underlying these differences is unclear. To identify key genes and pathways that coordinate floral organ senescence of ephemeral flowers, we identified transcripts in H. rosa-sinensis floral organs by 454 sequencing. During development, 2053 transcripts increased and 2135 decreased significantly in abundance. The senescence of the flower was associated with increased abundance of many hydrolytic genes, including aspartic and cysteine proteases, vacuolar processing enzymes, and nucleases. Pathway analysis suggested that transcripts altering significantly in abundance were enriched in functions related to cell wall-, aquaporin-, light/circadian clock-, autophagy-, and calcium-related genes. Finding enrichment in light/circadian clock-related genes fits well with the observation that hibiscus floral development is highly synchronized with light and the hypothesis that ageing/senescence of the flower is orchestrated by a molecular clock. Further study of these genes will provide novel insight into how the molecular clock is able to regulate the timing of programmed cell death in tissues.
authors: Institute of Life Science, Scuola Superiore Sant'Anna, Pisa, Italy.
authors: Alice
authors: 0000-0001-8001-4098
authors: A
authors: Trivellini
authors: Department of Agricultural and Environmental Sciences, Università degli Studi Milano, Milan, Italy.
authors: Giacomo
authors: 0000-0002-8796-4245
authors: G
authors: Cocetta
authors: The New Zealand Institute for Plant & Food Research Limited, Palmerston North, New Zealand.
authors: Donald A
authors: 0000-0002-5570-6460
authors: DA
authors: Hunter
authors: Department of Agriculture, Food and Environment, Università degli Studi di Pisa, Pisa, Italy.
authors: Paolo
authors: 0000-0002-4591-0994
authors: P
authors: Vernieri
authors: Department of Agricultural and Environmental Sciences, Università degli Studi Milano, Milan, Italy antonio.ferrante@unimi.it.
authors: Antonio
authors: A
authors: Ferrante
mesh_terms: D000375:Aging / Q000502:physiology; D002118:Calcium / Q000502:physiology; D002940:Circadian Rhythm / Q000502:physiology; D035264:Flowers / Q000254:growth & development* / Q000502:physiology; D018506:Gene Expression Regulation, Plant / Q000235:genetics / Q000502:physiology; D017343:Genes, Plant / Q000502:physiology; D031584:Hibiscus / Q000235:genetics / Q000254:growth & development* / Q000502:physiology; D020411:Oligonucleotide Array Sequence Analysis; D017382:Reactive Oxygen Species / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014157:Transcription Factors / Q000502:physiology; D059467:Transcriptome / Q000502:physiology*
chemical_list: D017382:Reactive Oxygen Species; D014157:Transcription Factors; D002118:Calcium
keywords: 454 sequencing; PCD; aquaporins; cell wall; light and circadian clock signalling; microarray; ovary; petal; style-stigma plus stamens.