Dataset Information

PREMATURE INTERNODE ELONGATION 1 coordinates internode elongation in response to florigenic signals at the shoot apex of rice

ABSTRACT: Flowering of several plant species is induced by exposure to specific photoperiods that promote the expression of florigenic proteins in the leaves and their subsequent translocation to the shoot apex, where they commit the meristem to a reproductive fate. Transition to reproductive growth at the apex is often accompanied by stem elongation, to expose flowers above the leaves and facilitate fertilization. However, how growth and inflorescence formation are coupled and how photoperiodic signals coordinate these processes at the apex is still unclear. We studied these mechanisms in rice, a short day plant. Here, we show that HEADING DATE 3a (Hd3a) and RICE FLOWERING LOCUS T 1 (RFT1), encoding components of the rice florigenic signal, are sufficient to repress expression of PREMATURE INTERNODE ELONGATION 1 (PINE1) at the shoot apex during the transition to flowering, thus promoting culm elongation. PINE1 encodes a nuclear C2H2 zinc finger transcriptional repressor that controls the mRNA abundance of GA3ox2, a gibberellin (GA) biosynthetic gene. These data uncover the existence of a regulatory network coordinating multiple aspects of phase transition, and indicate that GA-induced growth and activity of florigenic proteins at the shoot apex need to be strictly coupled.

ORGANISM(S): Oryza sativa

PROVIDER: GSE90493 | GEO | 2018/11/30

REPOSITORIES: GEO

ACCESS DATA

Dataset's files

Source:

			Action	DRS
		Other

Items per page:

1 - 1 of 1

Similar Datasets

Project description:The timing of reproductive development determines spike architecture and thus yield in temperate grasses such as barley (Hordeum vulgare L.). Reproductive development in barley is controlled by the photoperiod response gene Ppd-H1 which accelerates flowering time under long-day (LD) conditions. A natural mutation in Ppd-H1 prevalent in spring barley causes a reduced photoperiod response, and thus, late flowering under LD. However, it is not very well understood how LD and Ppd-H1 control pre-anthesis development, and thus spike architecture and yield in barley. We performed a detailed morphological analysis of the pre-anthesis development in the spring barley cultivar Scarlett and its wild barley derived introgression line S42-IL107, carrying the photoperiod responsive Ppd-H1 allele. Characterization of shoot apex development in these genotypes indicated that floral transition and initiation of floral primordia occurred under LD (16h light/ 8h dark) and short day (SD, 8h light/ 16h dark) conditions, while inflorescence and seed development strictly required LDs. Additionally, a fast photoperiod response in the presence of the dominant Ppd-H1 allele promoted floret fertility under LDs. To characterize the effects of the photoperiod and allelic variation at Ppd-H1 on gene expression during pre-anthesis development we performed RNA sequencing of leaves and developing main shoot apices during the vegetative phase and early stages of inflorescence development in Scarlett and S42-IL107 grown under SD and LD conditions. Main shoot apices of both genotypes were sampled at defined developmental stages, i.e. Waddington stage W0.5, W1.0, W2.0 and W3.5, respectively. Leaf samples were harvested from plants before (W1.0) and after floral transition (W2.0). We identified genes that were specifically regulated at floral transition independent of day-length and Ppd-H1 and thus may serve as markers for the staging of floral transition. Furthermore, we identified transcripts differentially expressed between photoperiods and between genotypes in leaves and in shoot apices. This set of transcripts might act as candidates downstream of Ppd-H1 and are correlated with the promotion of shoot apex development and higher floret fertility under LD and in the presence of the photoperiod responsive Ppd-H1 allele.

Project description:Stem internodes of grasses function in mechanical support, transport, and, in some species are a major sink organ for carbon in the form of cell wall polymers. To establish the rice elongating internode as a model for secondary cell wall development, we conducted cell wall composition, proteomic and metabolomic analyses of the second rice internode at booting stage. We measured major secondary cell wall components along eight segments of an elongating internode. Cellulose, lignin, and xylose increase as a percentage of cell wall material from the younger to the older internode segments, indicating active cell wall synthesis. With the whole elongating internode, we measured peptides via liquid-chromatography mass spectrometry (LC-MS) following trypsin digestion of size fractionated proteins. This identified a total of 3249 protein groups with at least two unique peptides, including many glycosyltransferases, acyltransferases, glycohyrolases, cell wall-localized proteins, and protein kinases that have or may have functions in cell wall biosynthesis or remodeling. In addition, GO over-representation analysis and KO pathway analysis indicate many proteins involved in biosynthetic processes, especially the synthesis of secondary metabolites such as phenylpropanoids, flavonoids, and tepenoids. Therefore, we also used LC-MS to measure methanol-extracted secondary metabolites from the whole internode at the elongation stage and three post-elongation stages, and from leaf and root at the second post-elongation stage. The results indicate secondary metabolites in stems are distinct from those of roots and leaves, and show different profiles during stem development. This study fills a void of knowledge of proteomics and metabolomics data for grass stems, especially of rice, and provides baseline knowledge for more detailed studies of cell wall synthesis and other biological processes during internode development. This and future work is aimed at optimizing stem development and cell wall composition of grasses to improve agronomic properties and biofuel production.

Dataset Information

PREMATURE INTERNODE ELONGATION 1 coordinates internode elongation in response to florigenic signals at the shoot apex of rice

Dataset's files

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets