Genetic Regulation of Embryonic Pattern Formation

Laux, Thomas; Würschum, Tobias; Breuninger, Holger

doi:10.1105/tpc.016014

Cited by 150 publications

(96 citation statements)

References 126 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As a result, the lens-shaped cell gives rise to the QC and the basal cell generates the columella (Laux et al, 2004). During the initiation of the axillary meristem, an auxin minimum region in the leaf axil is established through PIN-dependent auxin efflux .…”

Section: Mutually Exclusive Distribution Pattern Of Cytokinin and Auxmentioning

confidence: 99%

Type-B ARABIDOPSIS RESPONSE REGULATORs Specify the Shoot Stem Cell Niche by Dual Regulation of WUSCHEL

et al. 2017

View full text Add to dashboard Cite

ORCID IDs: 0000-0003-3103-8629 (W.J.M.); 0000-0002-3129-5206 (X.S.Z.)Plants are known for their capacity to regenerate the whole body through de novo formation of apical meristems from a mass of proliferating cells named callus. Exogenous cytokinin and auxin determine cell fate for the establishment of the stem cell niche, which is the vital step of shoot regeneration, but the underlying mechanisms remain unclear. Here, we show that type-B ARABIDOPSIS RESPONSE REGULATORs (ARRs), critical components of cytokinin signaling, activate the transcription of WUSCHEL (WUS), which encodes a key regulator for maintaining stem cells. In parallel, type-B ARRs inhibit auxin accumulation by repressing the expression of YUCCAs, which encode a key enzyme for auxin biosynthesis, indirectly promoting WUS induction. Both pathways are essential for de novo regeneration of the shoot stem cell niche. In addition, the dual regulation of type-B ARRs on WUS transcription is required for the maintenance of the shoot apical meristem in planta. Thus, our results reveal a long-standing missing link between cytokinin signaling and WUS regulator, and the findings provide critical information for understanding cell fate specification.

show abstract

Section: Mutually Exclusive Distribution Pattern Of Cytokinin and Auxmentioning

confidence: 99%

Type-B ARABIDOPSIS RESPONSE REGULATORs Specify the Shoot Stem Cell Niche by Dual Regulation of WUSCHEL

et al. 2017

View full text Add to dashboard Cite

show abstract

“…Early in embryogenesis, during the morphogenesis phase, the basic body plan of the plant is established with regional specification of apical-basal and radial domains from which morphological structures derive, fixation of polarity from specification of the shoot-root axis, and formation of embryonic tissue and organ systems (1)(2)(3). The morphogenesis phase is followed temporally by the maturation phase, although the two phases can overlap (4,5).…”

mentioning

confidence: 99%

Genes directly regulated by LEAFY COTYLEDON2 provide insight into the control of embryo maturation and somatic embryogenesis

Braybrook

Stone

Park

et al. 2006

Proc. Natl. Acad. Sci. U.S.A.

329

331

View full text Add to dashboard Cite

The B3 domain protein LEAFY COTYLEDON2 (LEC2) is required for several aspects of embryogenesis, including the maturation phase, and is sufficient to induce somatic embryo development in vegetative cells. Here, we demonstrate that LEC2 directly controls a transcriptional program involved in the maturation phase of seed development. Induction of LEC2 activity in seedlings causes rapid accumulation of RNAs normally present primarily during the maturation phase. Several RNAs encode proteins with known roles in maturation processes, including seed-storage and lipid-body proteins. Clustering analyses identified other LEC2-induced RNAs not previously shown to be involved in the maturation phase. We show further that genes encoding these maturation RNAs all possess in their 5 flanking regions RY motifs, DNA elements bound by other closely related B3 domain transcription factors. Our finding that recombinant LEC2 specifically binds RY motifs from the 5 flanking regions of LEC2-induced genes provides strong evidence that these genes represent transcriptional targets of LEC2. Although these LEC2-induced RNAs accumulate primarily during the maturation phase, we show that a subset, including AGL15 and IAA30, accumulate in seeds containing zygotes. We discuss how identification of LEC2 target genes provides a potential link between the roles of LEC2 in the maturation phase and in the induction of somatic embryogenesis.Arabidopsis ͉ B3 domain E mbryogenesis in higher plants can be divided conceptually into two distinct phases. Early in embryogenesis, during the morphogenesis phase, the basic body plan of the plant is established with regional specification of apical-basal and radial domains from which morphological structures derive, fixation of polarity from specification of the shoot-root axis, and formation of embryonic tissue and organ systems (1-3). The morphogenesis phase is followed temporally by the maturation phase, although the two phases can overlap (4, 5). During the maturation phase, embryo cell-division rates decline markedly, embryo cells acquire the ability to withstand desiccation, and embryo cell growth occurs, with the accumulation of storage reserves that comprise lipids and proteins in Arabidopsis (6, 7). At the end of the maturation phase, the embryo becomes quiescent metabolically as the seed desiccates.The maturation phase can be viewed as an interruption of an ancestral life cycle, as occurs in lower plants, in which there are no periods of maturation or dormancy separating the end of embryogenesis and the beginning of postembryonic development (4). Evolution of this unique mode of embryogenesis has enabled higher plants to make seeds. The ability to make seeds has provided tremendous selective advantages that, in part, account for the success of the angiosperms (8, 9). Little is known at a mechanistic level about the processes by which the maturation phase has been integrated into the higher plant life cycle. LEAFY COTYLEDON2 (LEC2), along with ABA INSEN-SITIVE3 (ABI3), and FUSCA3 (FUS3), have been im...

show abstract

“…1, A-C; Goldberg et al, 1994;Miller et al, 1999;Gehring et al, 2004;Laux et al, 2004;Moise et al, 2005). These compartments have different origins and play distinct roles in seed formation.…”

mentioning

confidence: 99%

“…The embryo proper, on the other hand, represents the new sporophytic generation and contains the shoot and root meristems that are responsible for generating organ systems of the mature plant after seed germination ( Fig. 1C; Goldberg et al, 1994;Laux et al, 2004).…”

mentioning

confidence: 99%