The maize Gα gene COMPACT PLANT2 functions in CLAVATA signalling to control shoot meristem size

Trees from temperate latitudes transition between growth and dormancy to survive dehydration and freezing stress during winter months. We used activation tagging to isolate a dominant mutation affecting release from dormancy and identified the corresponding gene EARLY BUD-BREAK 1 (EBB1). We demonstrate through positioning of the tag, expression analysis, and retransformation experiments that EBB1 encodes a putative APETALA2/Ethylene responsive factor transcription factor. Transgenic up-regulation of the gene caused early bud-flush, whereas down-regulation delayed bud-break. Native EBB1 expression was highest in actively growing apices, undetectable during the dormancy period, but rapidly increased before bud-break. The EBB1 transcript was localized in the L1/L2 layers of the shoot meristem and leaf primordia. EBB1-overexpressing transgenic plants displayed enlarged shoot meristems, open and poorly differentiated buds, and a higher rate of cell division in the apex. Transcriptome analyses of the EBB1 transgenics identified 971 differentially expressed genes whose expression correlated with the EBB1 expression changes in the transgenic plants. Promoter analysis among the differentially expressed genes for the presence of a canonical EBB1-binding site identified 65 putative target genes, indicative of a broad regulatory context of EBB1 function. Our results suggest that EBB1 has a major and integrative role in reactivation of meristem activity after winter dormancy.adaptation | phenology | regeneration | climate change

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“…48). Furthermore, in maize, a GPA1 ortholog regulates meristem activity in a CLAVATA-dependent manner (49).…”

Section: Discussionmentioning

confidence: 99%

EARLY BUD-BREAK 1 (EBB1) is a regulator of release from seasonal dormancy in poplar trees

Yordanov

Strauss

et al. 2014

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

134

119

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“…4E; Bommert et al 2013). TFs implicated in cell specification were generally activated by RA1; however, the SBP TF liguleless1 (lg1) was repressed (Fig.…”

Section: Figurementioning

confidence: 99%

Regulatory modules controlling maize inflorescence architecture

et al. 2013

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Genetic control of branching is a primary determinant of yield, regulating seed number and harvesting ability, yet little is known about the molecular networks that shape grain-bearing inflorescences of cereal crops. Here, we used the maize (Zea mays) inflorescence to investigate gene networks that modulate determinacy, specifically the decision to allow branch growth. We characterized developmental transitions by associating spatiotemporal expression profiles with morphological changes resulting from genetic perturbations that disrupt steps in a pathway controlling branching. Developmental dynamics of genes targeted in vivo by the transcription factor RAMOSA1, a key regulator of determinacy, revealed potential mechanisms for repressing branches in distinct stem cell populations, including interactions with KNOTTED1, a master regulator of stem cell maintenance. Our results uncover discrete developmental modules that function in determining grass-specific morphology and provide a basis for targeted crop improvement and translation to other cereal crops with comparable inflorescence architectures.

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“…These dried samples were mounted, dissected, sputter-coated with gold palladium, and then viewed at 10 kV accelerating voltage with a FEI XL30 environmental scanning electron microscope. STS1-YFP fluorescence was imaged by confocal and two-photon microscopy as described (Bommert et al, 2013). PIN1-YFP and DR5-RFP were imaged with a Zeiss 710, using freshly dissected live tissue.…”

Section: Scanning Electron and Confocal Microscopymentioning

confidence: 99%

The Maize PI/GLO Ortholog Zmm16/sterile tassel silky ear1 Interacts with the Zygomorphy and Sex Determination Pathways in Flower Development

et al. 2015

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In monocots and eudicots, B class function specifies second and third whorl floral organ identity as described in the classic ABCE model. Grass B class APETALA3/DEFICIENS orthologs have been functionally characterized; here, we describe the positional cloning and characterization of a maize (Zea mays) PISTILLATA/GLOBOSA ortholog Zea mays mads16 (Zmm16)/ sterile tassel silky ear1 (sts1). We show that, similar to many eudicots, all the maize B class proteins bind DNA as obligate heterodimers and positively regulate their own expression. However, sts1 mutants have novel phenotypes that provide insight into two derived aspects of maize flower development: carpel abortion and floral asymmetry. Specifically, we show that carpel abortion acts downstream of organ identity and requires the growth-promoting factor grassy tillers1 and that the maize B class genes are expressed asymmetrically, likely in response to zygomorphy of grass floral primordia. Further investigation reveals that floral phyllotactic patterning is also zygomorphic, suggesting significant mechanistic differences with the wellcharacterized models of floral polarity. These unexpected results show that despite extensive study of B class gene functions in diverse flowering plants, novel insights can be gained from careful investigation of homeotic mutants outside the core eudicot model species.

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The maize Gα gene COMPACT PLANT2 functions in CLAVATA signalling to control shoot meristem size

Cited by 241 publications

References 31 publications

EARLY BUD-BREAK 1 (EBB1) is a regulator of release from seasonal dormancy in poplar trees

EARLY BUD-BREAK 1 (EBB1) is a regulator of release from seasonal dormancy in poplar trees

Regulatory modules controlling maize inflorescence architecture

The Maize PI/GLO Ortholog Zmm16/sterile tassel silky ear1 Interacts with the Zygomorphy and Sex Determination Pathways in Flower Development

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