Control of cell proliferation, endoreduplication, cell size, and cell death by the retinoblastoma-related pathway in maize endosperm
AuthorsSabelli, Paolo A.
Dante, Ricardo Augusto
Lizarraga, Lucina E.
Nguyen, Hong N.
Brown, Sara W.
Layton, Tracy M.
Larkins, Brian A.
KAUST DepartmentCenter for Desert Agriculture
MetadataShow full item record
AbstractThe endospermof cereal grains is one of the most valuable products of modern agriculture. Cereal endosperm development comprises different phases characterized by mitotic cell proliferation, endoreduplication, the accumulation of storage compounds, and programmed cell death. Although manipulation of these processes could maximize grain yield, how they are regulated and integrated is poorly understood. We show that the Retinoblastoma-related (RBR) pathway controls key aspects of endosperm development in maize. Down-regulation of RBR1 by RNAi resulted in up-regulation of RBR3-type genes, as well as the MINICHROMOSOME MAINTENANCE 2-7 gene family and PROLIFERATING CELL NUCLEAR ANTIGEN, which encode essential DNA replication factors. Both the mitotic and endoreduplication cell cycles were stimulated. Developing transgenic endosperm contained 42-58% more cells and ~70% more DNA than wild type, whereas there was a reduction in cell and nuclear sizes. In addition, cell death was enhanced. The DNA content of mature endosperm increased 43% upon RBR1 downregulation, whereas storage protein content and kernel weight were essentially not affected. Down-regulation of both RBR1 and CYCLIN DEPENDENT KINASE A (CDKA);1 indicated that CDKA;1 is epistatic to RBR1 and controls endoreduplication through an RBR1- dependent pathway. However, the repressive activity of RBR1 on downstream targets was independent from CDKA;1, suggesting diversification of RBR1 activities. Furthermore, RBR1 negatively regulated CDK activity, suggesting the presence of a feedback loop. These results indicate that the RBR1 pathway plays a major role in regulation of different processes during maize endosperm development and suggest the presence of tissue/organlevel regulation of endosperm/seed homeostasis.
PublisherNational Academy of Sciences
PubMed Central IDPMC3651506
- RBR3, a member of the retinoblastoma-related family from maize, is regulated by the RBR1/E2F pathway.
- Authors: Sabelli PA, Dante RA, Leiva-Neto JT, Jung R, Gordon-Kamm WJ, Larkins BA
- Issue date: 2005 Sep 13
- Cyclin-dependent kinase complexes in developing maize endosperm: evidence for differential expression and functional specialization.
- Authors: Dante RA, Sabelli PA, Nguyen HN, Leiva-Neto JT, Tao Y, Lowe KS, Hoerster GJ, Gordon-Kamm WJ, Jung R, Larkins BA
- Issue date: 2014 Feb
- A dominant negative mutant of cyclin-dependent kinase A reduces endoreduplication but not cell size or gene expression in maize endosperm.
- Authors: Leiva-Neto JT, Grafi G, Sabelli PA, Dante RA, Woo YM, Maddock S, Gordon-Kamm WJ, Larkins BA
- Issue date: 2004 Jul
- Water deficit inhibits cell division and expression of transcripts involved in cell proliferation and endoreduplication in maize endosperm.
- Authors: Setter TL, Flannigan BA
- Issue date: 2001 Jul
- Expression, regulation and activity of a B2-type cyclin in mitotic and endoreduplicating maize endosperm.
- Authors: Sabelli PA, Dante RA, Nguyen HN, Gordon-Kamm WJ, Larkins BA
- Issue date: 2014