Abstract
The mechanisms controlling the transcription of gene sets in specific regions of a plant embryo shortly after fertilization remain unknown. Previously, we showed that G564 mRNA, encoding a protein of unknown function, accumulates to high levels in the giant suspensor of both Scarlet Runner Bean (SRB) and Common Bean embryos, and a cis-regulatory module containing three unique DNA sequences, designated as the 10-bp, Region 2, and Fifth motifs, is required for G564 suspensor-specific transcription [Henry KF, et al. (2015) Plant Mol Biol 88:207-217; Kawashima T, et al. (2009) Proc Natl Acad Sci USA 106:3627-3632]. We tested the hypothesis that these motifs are also required for transcription of the SRB GA 20-oxidase gene, which encodes a gibberellic acid hormone biosynthesis enzyme and is co-expressed with G564 at a high level in giant bean suspensors. We used deletion and gain-of-function experiments in transgenic tobacco embryos to show that two GA 20-oxidase DNA regions are required for suspensor-specific transcription, one in the 5′ UTR (+119 to +205) and another in the 5′ upstream region (−341 to −316). Mutagenesis of sequences in these two regions determined that the cis-regulatory motifs required for G564 suspensor transcription are also required for GA 20-oxidase transcription within the suspensor, although the motif arrangement differs. Our results demonstrate the flexibility of motif positioning within a cis-regulatory module that activates gene transcription within giant bean suspensors and suggest that G564 and GA 20-oxidase comprise part of a suspensor gene regulatory network.
| Original language | English |
|---|---|
| Pages (from-to) | E5824-E5833 |
| Journal | Proceedings of the National Academy of Sciences of the United States of America |
| Volume | 115 |
| Issue number | 25 |
| DOIs | |
| State | Published - Jun 19 2018 |
Bibliographical note
Funding Information:ACKNOWLEDGMENTS. We thank present and past members of our laboratory for discussion and advice with this project, especially Min Chen and Xiaomeng Wu for generating SRB and Common Bean embryo transcrip-tomes; Professor John Harada for insightful comments on our suspensor cis-element research; and Professor Jeff Long for assistance with nonradioactive in situ hybridization. We dedicate this paper to the memory of our close friend and mentor, Professor Eric Davidson, who was a visionary in the field of developmental biology, a pioneer on the organization of eukaryotic gene regulatory networks, and who provided us with perceptive advice on cis-regulatory module identification. This work was funded by a grant from the National Science Foundation Plant Genome Program.
Funding Information:
We thank present and past members of our laboratory for discussion and advice with this project, especially Min Chen and Xiaomeng Wu for generating SRB and Common Bean embryo transcrip-tomes; Professor John Harada for insightful comments on our suspensor cis-element research; and Professor Jeff Long for assistance with nonradioactive in situ hybridization. We dedicate this paper to the memory of our close friend and mentor, Professor Eric Davidson, who was a visionary in the field of developmental biology, a pioneer on the organization of eukaryotic gene regulatory networks, and who provided us with perceptive advice on cis-regulatory module identification. This work was funded by a grant from the National Science Foundation Plant Genome Program.
Publisher Copyright:
© 2018 National Academy of Sciences. All Rights Reserved.
Keywords
- Cis-regulatory modules
- Plant embryos
- Promoter analysis
- Scarlet Runner Bean
- Suspensor
ASJC Scopus subject areas
- General