Attention:The NSF Public Access Repository (PAR) system and access will be unavailable from 11:00 PM ET on Thursday, August 13 until 12:00 AM ET on Friday, August 14 due to maintenance. We apologize for the inconvenience.

Explore Research Products in the PAR
It may take a few hours for recently added research products to appear in PAR search results.


Title: Mechanisms Of Meristem Maintenance By Maize Transcriptional Corepressors
ABSTRACT The formation of the plant body proceeds in a sequential post-embryonic manner through the action of meristems. Tightly coordinated meristem regulation is required for development and reproductive success, eventually determining yield in crop species. In maize, the REL2 family of transcriptional corepressors includes four members, REL2, RELK1 (REL2-LIKE1), RELK2, and RELK3. In a screen forrel2enhancers, we identified shorter double mutants with enlarged female inflorescence meristems (IMs) carrying mutations inRELK1. Expression and genetic analysis indicate thatREL2andRELK1cooperatively regulate female IM development by controlling genes involved in redox balance, hormone homeostasis, and differentiation, ultimately tipping the meristem toward an environment favorable to expanded expression of theZmWUSCHEL1gene, a key stem-cell promoting transcription factor. We further demonstrate thatRELKgenes have partially redundant yet diverse functions in the maintenance of various meristem types during development. By exploiting subtle increases in ear IM size inrel2heterozygous plants, we also show that extra rows of kernels are formed across a diverse set of F1 hybrids. Our findings reveal that the REL2 family maintains development from embryonic initiation to reproductive growth and can potentially be harnessed for increasing seed yield in a major crop species. One sentence summaryREL2-RELKs fine tune hormone and chemical cues to prevent expanded expression of ZmWUSCHEL1 in maize inflorescence meristems, and can potentially be harnessed for increasing seed yield in hybrids.  more » « less
Award ID(s):
2026561
PAR ID:
10531692
Author(s) / Creator(s):
; ; ; ; ; ; ;
Publisher / Repository:
bioRxiv
Date Published:
Format(s):
Medium: X
Institution:
bioRxiv
Sponsoring Org:
National Science Foundation
More Like this
  1. ; ; ; ; ; ; ; (, Plant Physiology)
    Abstract The formation of the plant body proceeds in a sequential postembryonic manner through the action of meristems. Tightly coordinated meristem regulation is required for development and reproductive success, eventually determining yield in crop species. In maize (Zea mays), the RAMOSA1 ENHANCER LOCUS2 (REL2) family of transcriptional corepressors includes four members, REL2, RELK1 (REL2-LIKE1), RELK2, and RELK3. In a screen for rel2 enhancers, we identified shorter double mutants with enlarged ear inflorescence meristems (IMs) carrying mutations in RELK1. Expression and genetic analysis indicated that REL2 and RELK1 cooperatively regulate ear IM development by controlling genes involved in redox balance, hormone homeostasis, and differentiation, ultimately tipping the meristem toward an environment favorable to expanded expression of the ZmWUSCHEL1 gene, which encodes a key stem-cell promoting transcription factor. We further demonstrated that RELK genes have partially redundant yet diverse functions in the maintenance of various meristem types during development. By exploiting subtle increases in ear IM size in rel2 heterozygous plants, we also showed that extra rows of kernels are formed across a diverse set of F1 hybrids. Our findings reveal that the REL2 family maintains development from embryonic initiation to reproductive growth and can potentially be harnessed for increasing seed yield in a major crop species. 
    more » « less
  2. ; ; ; ; ; ; ; ; ; ; et al (, Nature Communications)
    Abstract In maize, several yield-related traits are associated with meristem activity, regulated by CLAVATA3/EMBRYO SURROUNDING REGION-related (CLE) peptide signals perceived by CLAVATA(CLV) receptors in the CLAVATA-WUSCHEL (CLV-WUS) pathway. However, additional signaling pathways in maize meristem development remain poorly understood. Here, we identify three receptor-like kinases, ZmERECTA1 (ZmER1), ZmER2 and ZmER1-like (ZmERL), and their ligands, EPIDERMAL PATTERNING FACTOR-like (ZmEPFL), as critical regulators of meristem activity, plant architecture, and ear development. We demonstrate that ZmER receptors act redundantly, with ZmER1 playing a primary role.Zmer1mutants have compact architecture, enlarged inflorescence meristems (IMs), and increased kernel row numbers (KRNs), while higher-orderZmermutants display exacerbated phenotypes. We further reveal that ZmER1 specifically binds to five EPFL peptides, which act redundantly in ear development regulation. Furthermore, we find thatZmWUS1is upregulated inZmermutants and mutation inZmwus1partially suppress the enlarged IM ofZmer1mutants. We also generate weakZmer1alleles with enhanced yield traits, including reduced leaf angles and increased KRN. These findings offer valuable insights into ER-EPFL signaling in maize meristem development and provide promising genetic targets for breeding high-yield maize varieties through optimized plant and ear architecture. 
    more » « less
  3. ; ; ; ; ; (, Proceedings of the National Academy of Sciences)
    null (Ed.)
    Plant meristems are self-renewing groups of pluripotent stem cells that produce lateral organs in a stereotypical pattern. Of interest is how the radially symmetrical meristem produces laminar lateral organs. Both the male and female inflorescence meristems of the dominant Fascicled ear ( Fas1 ) mutant fail to grow as a single point and instead show deep branching. Positional cloning of two independent Fas1 alleles identified an ∼160 kb region containing two floral genes, the MADS-box gene, zmm8 , and the YABBY gene, drooping leaf2 ( drl2 ). Both genes are duplicated within the Fas1 locus and spatiotemporally misexpressed in the mutant inflorescence meristems. Increased zmm8 expression alone does not affect inflorescence development; however, combined misexpression of zmm8 , drl2 , and their syntenic paralogs zmm14 and drl1 , perturbs meristem organization. We hypothesize that misexpression of the floral genes in the inflorescence and their potential interaction cause ectopic activation of a laminar program, thereby disrupting signaling necessary for maintenance of radially symmetrical inflorescence meristems. Consistent with this hypothesis, RNA sequencing and in situ analysis reveal altered expression patterns of genes that define distinct zones of the meristem and developing leaf. Our findings highlight the importance of strict spatiotemporal patterns of expression for both zmm8 and drl2 and provide an example of phenotypes arising from tandem gene duplications. 
    more » « less
  4. ; ; ; ; ; ; (, bioRxiv)
    SUMMARY WUSCHEL (WUS) is transcription factor vital for stem cell proliferation in plant meristems. In maize,ZmWUS1is expressed in the inflorescence meristem, including the central zone, the reservoir of stem cells.ZmWUS1overexpression in theBarren inflorescence3mutant leads to defects in inflorescence development. Here, single-cell ATAC-seq analysis shows thatZmWUS1overexpression alters chromatin accessibility throughout the central zone. The CAATAATGC motif, a known homeodomain recognition site, is predominantly observed in the regions with increased chromatin accessibility suggesting ZmWUS1 is an activator in the central zone. Regions with decreased chromatin accessibility feature various motifs and are adjacent toAUXIN RESPONSE FACTORgenes, revealing negative regulation of auxin signaling in the central zone. DAP-seq of ZmWUS1 identified the TGAATGAA motif, abundant in epidermal accessible chromatin compared to the central zone. These findings highlight ZmWUS1’s context-dependent mechanisms for stem cell maintenance in the inflorescence meristem. 
    more » « less
  5. ; ; ; ; (, Plant, Cell & Environment)
    ABSTRACT A fascinating feature of land plants is their ability to continually initiate new tissues and organs throughout their lifespan, driven by a pool of pluripotent stem cells located in meristems. In seed plants, various types of meristems are initiated and maintained during the sporophyte generation, while their gametophytes lack meristems and rely on sporophyte tissues for growth. In contrast, seed‐free vascular plants, such as ferns, develop meristems during both the sporophyte and gametophyte generations, allowing for the independent growth of both generations. Recent findings have highlighted both conserved and lineage‐specific roles of the HAIRY MERISTEM (HAM) family of GRAS‐domain transcriptional regulators in various meristems throughout the land plant lifecycle. Here, we review and discuss howHAMgenes maintain meristem indeterminacy in both sporophytes and gametophytes, with a focus on studies performed in two model species: the flowering plantArabidopsis thalianaand the fernCeratopteris richardii. Additionally, we summarize the crucial and tightly regulated functions of the microRNA171 (miR171)‐HAM regulatory modules, which define HAM spatial patterns and activities during meristem development across various meristem identities in land plants. 
    more » « less
  • Citation Formats
  • MLA
  • APA
  • Chicago
  • BibTeX
  • Text Encoded Conversion
  • XML
  • Save / Share this Record
  • Send to Email