Hypoxia Triggers Meiotic Fate Acquisition in Maize

Kelliher, Timothy; Walbot, Virginia

doi:10.1126/science.1220080

Cited by 195 publications

(224 citation statements)

References 33 publications

Supporting

Mentioning

213

Contrasting

Unclassified

Order By: Relevance

“…2B and Dataset S2) (10). Few phasiRNAs were observed at 0.2 mm when germinal and initial somatic fate setting starts from pluripotent stem cells (18,19). After 24 h at the 0.4-mm stage when premeiotic archesporial (AR) and three somatic cell types-epidermis, endothecium, and bipotent secondary parietal layer (SPL)-exist, 21-nt phasiRNAs peak in quantity and diversity, comprising 60% of all 21-nt RNAs (Fig.…”

Section: Resultsmentioning

confidence: 99%

“…Anthers lack an organizing center, in contrast to the meristem regions of shoots and roots. Meristems organize a continuum of developmental stages displaced from the stem cell population, whereas anthers "self-organize" tissue layers and the entire organ progresses through development as one unit with high fidelity and temporal regularity (15,18,32). The potential movement of phasiRNAs from the site of biogenesis to neighboring cell layers (Fig.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Spatiotemporally dynamic, cell-type–dependent premeiotic and meiotic phasiRNAs in maize anthers

Zhai

Zhang

Arikit

et al. 2015

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

Self Cite

294

529

View full text Add to dashboard Cite

Maize anthers, the male reproductive floral organs, express two classes of phased small-interfering RNAs (phasiRNAs). PhasiRNA precursors are transcribed by RNA polymerase II and map to lowcopy, intergenic regions similar to PIWI-interacting RNAs (piRNAs) in mammalian testis. From 10 sequential cohorts of staged maize anthers plus mature pollen we find that 21-nt phased siRNAs from 463 loci appear abruptly after germinal and initial somatic cell fate specification and then diminish, whereas 24-nt phasiRNAs from 176 loci coordinately accumulate during meiosis and persist as anther somatic cells mature and haploid gametophytes differentiate into pollen. Male-sterile ocl4 anthers defective in epidermal signaling lack 21-nt phasiRNAs. Male-sterile mutants with subepidermal defects-mac1 (excess meiocytes), ms23 (defective pretapetal cells), and msca1 (no normal soma or meiocytes)-lack 24-nt phasiRNAs. ameiotic1 mutants (normal soma, no meiosis) accumulate both 21-nt and 24-nt phasiRNAs, ruling out meiotic cells as a source or regulator of phasiRNA biogenesis. By in situ hybridization, miR2118 triggers of 21-nt phasiRNA biogenesis localize to epidermis; however, 21-PHAS precursors and 21-nt phasiRNAs are abundant subepidermally. The miR2275 trigger, 24-PHAS precursors, and 24-nt phasiRNAs all accumulate preferentially in tapetum and meiocytes. Therefore, each phasiRNA type exhibits independent spatiotemporal regulation with 21-nt premeiotic phasiRNAs dependent on epidermal and 24-nt meiotic phasiRNAs dependent on tapetal cell differentiation. Maize phasiRNAs and mammalian piRNAs illustrate putative convergent evolution of small RNAs in male reproduction. phasiRNAs | anther development | piRNAs | tapetum | tasiRNAs D iverse small RNAs exist in male reproductive cells of animals and plants. In animals, PIWI proteins, a subfamily of the ARGONAUTEs, and their interacting piRNAs are required for spermatogenesis; mutants defective for the PIWI-encoding genes fail to produce mature sperm (1-3). Whereas most Drosophila piRNAs are repeat-derived and function to silence transposable elements (TEs) (4, 5), mammalian piRNAs predominantly map to unique intergenic regions and have unclear but essential roles during gonad development. Based on their expression timing, different sizes, and distinctive PIWI partners, mammalian piRNAs are further classified as prepachytene or pachytene (6). Given the continuum of developmental stages in the testes, the prepachytene class is characteristic of gonads in which no cells have reached pachytene, whereas the pachytene-associated small RNAs are characteristic of gonads in which the most advanced germ line cells have reached this meiotic stage and all prior stages are also present in the more immature zone of the gonad.In flowering plants, the anther is equivalent to the mammalian testes in that it consists of multiple somatic cell types required to support the premeiotic, meiotic, and postmeiotic haploid cells. In contrast to the continuum of mammalian gonads, however, an entire anther progres...

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Spatiotemporally dynamic, cell-type–dependent premeiotic and meiotic phasiRNAs in maize anthers

Zhai

Zhang

Arikit

et al. 2015

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

Self Cite

294

529

View full text Add to dashboard Cite

show abstract

“…Loss-of-function mutation in ROXY1 leads to petal defects with normal fertility, and double roxy1 roxy2 mutants are male sterile and do not produce pollen, showing redundant functions in anther development. Related genes also control anther development in grasses, as MALE STERILE CONVERTED ANTHER1 (MSCA1) in maize and MICROSPORELESS1 (MIL1) in rice, encode close homologs of ROXY (Hong et al, 2012;Kelliher and Walbot, 2012). ROXY proteins interact with TGA class bZIP transcription factors and are thought to posttranslationally modify their activities (Li et al, 2009(Li et al, , 2011Murmu et al, 2010).…”

Section: Introductionmentioning

confidence: 99%

A Maize Glutaredoxin Gene,Abphyl2,Regulates Shoot Meristem Size and Phyllotaxy

et al. 2015

View full text Add to dashboard Cite

Phyllotaxy describes the geometric arrangement of leaves and is important for plant productivity. Auxin is well known to regulate phyllotactic patterns via PIN1-dependent auxin polar transport, and studies of maize (Zea mays) aberrant phyllotaxy1 (abph1) mutants suggest the importance of auxin and cytokinin signaling for control of phyllotaxy. However, whether additional regulators control these patterns is poorly understood. Here, we report a new dominant maize mutant, Aberrant phyllotaxy2 (Abph2), in which the shoot meristems are enlarged and the phyllotactic pattern switches from alternate to decussate. Map-based cloning revealed that the Abph2 mutation was caused by transposition of a glutaredoxin gene, MALE STERILE CONVERTED ANTHER1 (MSCA1), which gained an altered expression pattern in Abph2 mutant embryos. msca1 loss-of-function mutants have reduced meristem size and revealed a novel function of glutaredoxins in meristem growth. In addition, MSCA1 interacts with a TGA transcription factor, FASCIATED EAR4, suggesting a novel regulatory module for regulating shoot meristem size.

show abstract

“…These genes encode small secreted proteins identified as the putative ligands of the MSP1 or EXS/EMS1 receptor kinases (Sheridan et al, , 1999Yang et al, 2003Yang et al, , 2005Zhao et al, 2008;Wang et al, 2012;Kelliher and Walbot, 2012). Unlike in Arabidopsis, in rice and maize this pathway also affects female sporogenesis, indicating differences in the mechanism of repression of additional sporocytes Zhao et al, 2008;Nonomura et al, 2003).…”

Section: The Acquisition and Restriction Of Reproductive Fatementioning

confidence: 99%

Plant germline formation: common concepts and developmental flexibility in sexual and asexual reproduction

2015

View full text Add to dashboard Cite

The life cycle of flowering plants alternates between two heteromorphic generations: a diploid sporophytic generation and a haploid gametophytic generation. During the development of the plant reproductive lineages -the germlines -typically, single sporophytic (somatic) cells in the flower become committed to undergo meiosis. The resulting spores subsequently develop into highly polarized and differentiated haploid gametophytes that harbour the gametes. Recent studies have provided insights into the genetic basis and regulatory programs underlying cell specification and the acquisition of reproductive fate during both sexual reproduction and asexual (apomictic) reproduction. As we review here, these recent advances emphasize the importance of transcriptional, translational and post-transcriptional regulation, and the role of epigenetic regulatory pathways and hormonal activity.

show abstract

Hypoxia Triggers Meiotic Fate Acquisition in Maize

Cited by 195 publications

References 33 publications

Spatiotemporally dynamic, cell-type–dependent premeiotic and meiotic phasiRNAs in maize anthers

Spatiotemporally dynamic, cell-type–dependent premeiotic and meiotic phasiRNAs in maize anthers

A Maize Glutaredoxin Gene,Abphyl2,Regulates Shoot Meristem Size and Phyllotaxy

Plant germline formation: common concepts and developmental flexibility in sexual and asexual reproduction

Contact Info

Product

Resources

About