scholarly journals Lateral organ diversification in plants mediated by the ALOG protein family of transcription factors

2019 ◽  
Author(s):  
Satoshi Naramoto ◽  
Victor Arnold Shivas Jones ◽  
Nicola Trozzi ◽  
Mayuko Sato ◽  
Kiminori Toyooka ◽  
...  
Keyword(s):  
Cell Number ◽  
Land Plant ◽  
Marchantia Polymorpha ◽  
Terrestrial Environment ◽  
Rice Mutant ◽  
Lateral Organs ◽  
Morphological Adaptations ◽  
Family Protein ◽  
Lateral Organ ◽  
Meristem Maintenance

AbstractLand plant shoot structures evolved a diversity of lateral organs as morphological adaptations to the terrestrial environment, in which lateral organs independently evolved in each lineage in the sporophyte or gametophyte generation. The gametophyte meristem of the basally-diverging plant Marchantia polymorpha produces axes with non-photosynthetic scale-like lateral organs instead of leaves. Here we report that an ALOG (Arabidopsis LSH1 and Oryza G1) family protein in Marchantia, MpTAWAWA1 (MpTAW1), regulates meristem maintenance and lateral organ development. A mutation in MpTAW1, preferentially expressed in lateral organs, induces lateral organs with mis-specified identity and increased cell number, and furthermore, causes defects in apical meristem maintenance. Remarkably, MpTAW1 expression rescued the elongated-spikelet phenotype of a rice mutant of MpTAW1 homologue. This suggests that ALOG genes are co-opted to specify lateral organ identities in both gametophyte and sporophyte shoots by repressing lateral organ growth. We propose that the recruitment of ALOG-mediated lateral organ modification was in part responsible for the convergent evolution of independently-evolved lateral organs among highly divergent plant lineages and contributed to the morphological diversification of land plants.

scholarly journals Deep evolutionary origin of gamete-directed zygote activation by KNOX/BELL transcription factors in green plants

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Tetsuya Hisanaga ◽  
Shota Fujimoto ◽  
Yihui Cui ◽  
Katsutoshi Sato ◽  
Ryosuke Sano ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Transcription Factors ◽  
Chlamydomonas Reinhardtii ◽  
Plant Species ◽  
Land Plant ◽  
Land Plants ◽  
Marchantia Polymorpha ◽  
Mating Types ◽  
Meristem Maintenance

KNOX and BELL transcription factors regulate distinct steps of diploid development in plants. In the green alga Chlamydomonas reinhardtii, KNOX and BELL proteins are inherited by gametes of the opposite mating types and heterodimerize in zygotes to activate diploid development. By contrast, in land plants such as Physcomitrium patens and Arabidopsis thaliana, KNOX and BELL proteins function in meristem maintenance and organogenesis during the later stages of diploid development. However, whether the contrasting functions of KNOX and BELL were acquired independently in algae and land plants is currently unknown. Here, we show that in the basal land plant species Marchantia polymorpha, gamete-expressed KNOX and BELL are required to initiate zygotic development by promoting nuclear fusion in a manner strikingly similar to that in C. reinhardtii. Our results indicate that zygote activation is the ancestral role of KNOX/BELL transcription factors, which shifted toward meristem maintenance as land plants evolved.

scholarly journals Deep evolutionary origin of gamete-directed zygote activation by KNOX/BELL transcription factors in green plants

2020 ◽  
Author(s):  
Tetsuya Hisanaga ◽  
Shota Fujimoto ◽  
Yihui Cui ◽  
Katsutoshi Sato ◽  
Ryosuke Sano ◽  
...  
Keyword(s):  
Transcription Factors ◽  
Chlamydomonas Reinhardtii ◽  
Plant Species ◽  
Green Alga ◽  
Land Plant ◽  
Land Plants ◽  
Marchantia Polymorpha ◽  
Mating Types ◽  
Meristem Maintenance

AbstractKNOX and BELL transcription factors regulate distinct steps of diploid development in the green lineages. In the green alga Chlamydomonas reinhardtii, KNOX and BELL proteins are inherited by gametes of the opposite mating types, and heterodimerize in zygotes to activate diploid development. By contrast, in land plants such as Physcomitrella and Arabidopsis, KNOX and BELL proteins function in meristem maintenance and organogenesis during the later stages of diploid development. However, whether the contrasting functions of KNOX and BELL were acquired independently in algae and land plants is currently unknown. Here we show that in the basal land plant species Marchantia polymorpha, gamete-expressed KNOX and BELL are required to initiate zygotic development by promoting nuclear fusion in a manner strikingly similar to that of C. reinhardtii. Our results indicate that zygote activation is the ancestral role of KNOX/BELL transcription factors, which shifted toward meristem maintenance as land plants evolved.

scholarly journals ASYMMETRIC LEAVES1 reveals knox gene redundancy in Arabidopsis

Development ◽  
2002 ◽  
Vol 129 (8) ◽  
pp. 1957-1965 ◽  
Author(s):  
Mary E. Byrne ◽  
Joseph Simorowski ◽  
Robert A. Martienssen
Keyword(s):  
Shoot Apical Meristem ◽  
Apical Meristem ◽  
Cell Function ◽  
The Novel ◽  
Knox Gene ◽  
Knox Genes ◽  
Lateral Organs ◽  
Gene Redundancy ◽  
Lateral Organ ◽  
Meristem Maintenance

The shoot apical meristem comprises undifferentiated stem cells and their derivatives, which include founder cells for lateral organs such as leaves. Meristem maintenance and lateral organ specification are regulated in part by negative interactions between the myb domain transcription factor ASYMMETRIC LEAVES1, which is expressed in lateral organ primordia, and homeobox transcription factors which are expressed in the shoot apical meristem (knox genes). The knox gene SHOOT MERISTEMLESS (STM) negatively regulates ASYMMETRIC LEAVES1 (AS1) which, in turn, negatively regulates other knox genes including KNAT1 and KNAT2, and positively regulates the novel gene LATERAL ORGAN BOUNDARIES (LOB). Genetic interactions with a second gene, ASYMMETRIC LEAVES2 (AS2), indicate it acts at the same position in this hierarchy as AS1. We have used a second-site suppressor screen to isolate mutations in KNAT1 and we show that KNAT1 is partially redundant with STM in regulating stem cell function. Mutations in KNAT2 show no such interaction. We discuss the regulation and evolution of redundancy among knox genes.

scholarly journals Peculiar Evolutionary History of miR390-Guided TAS3-Like Genes in Land Plants

2013 ◽  
Vol 2013 ◽  
pp. 1-14 ◽  
Author(s):  
Maria S. Krasnikova ◽  
Denis V. Goryunov ◽  
Alexey V. Troitsky ◽  
Andrey G. Solovyev ◽  
Lydmila V. Ozerova ◽  
...  
Keyword(s):  
Genomic Dna ◽  
Physcomitrella Patens ◽  
Land Plant ◽  
Plant Evolution ◽  
Marchantia Polymorpha ◽  
History Of ◽  
Molecular Machinery ◽  
Specific Mrnas ◽  
Land Plant Evolution ◽  
Phylogenetic Profiling

PCR-based approach was used as a phylogenetic profiling tool to probe genomic DNA samples from representatives of evolutionary distant moss taxa, namely, classes Bryopsida, Tetraphidopsida, Polytrichopsida, Andreaeopsida, and Sphagnopsida. We found relatives of allPhyscomitrella patensmiR390 and TAS3-like loci in these plant taxa excluding Sphagnopsida. Importantly, cloning and sequencing ofMarchantia polymorphagenomic DNA showed miR390 and TAS3-like sequences which were also found among genomic reads ofM. polymorphaat NCBI database. Our data suggest that the ancient plant miR390-dependent TAS molecular machinery firstly evolved to target AP2-like mRNAs in Marchantiophyta and only then both ARF- and AP2-specific mRNAs in mosses. The presented analysis shows that moss TAS3 families may undergone losses of tasiAP2 sites during evolution toward ferns and seed plants. These data confirm that miR390-guided genes coding for ARF- and AP2-specific ta-siRNAs have been gradually changed during land plant evolution.

Development and Molecular Genetics of Marchantia polymorpha

2021 ◽  
Vol 72 (1) ◽  
Author(s):  
Takayuki Kohchi ◽  
Katsuyuki T. Yamato ◽  
Kimitsune Ishizaki ◽  
Shohei Yamaoka ◽  
Ryuichi Nishihama
Keyword(s):  
Model Organism ◽  
Land Plant ◽  
Marchantia Polymorpha ◽  
Annual Review ◽  
Publication Date ◽  
Molecular Tools ◽  
Genetic Redundancy ◽  
Morphological Differences ◽  
Evo Devo ◽  
Basal Position

Bryophytes occupy a basal position in the monophyletic evolution of land plants and have a life cycle in which the gametophyte generation dominates over the sporophyte generation, offering a significant advantage in conducting genetics. Owing to its low genetic redundancy and the availability of an array of versatile molecular tools, including efficient genome editing, the liverwort Marchantia polymorpha has become a model organism of choice that provides clues to the mechanisms underlying eco-evo-devo biology in plants. Recent analyses of developmental mutants have revealed that key genes in developmental processes are functionally well conserved in plants, despite their morphological differences, and that lineage-specific evolution occurred by neo/subfunctionalization of common ancestral genes. We suggest that M. polymorpha is an excellent platform to uncover the conserved and diversified mechanisms underlying land plant development. Expected final online publication date for the Annual Review of Plant Biology, Volume 72 is May 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

scholarly journals LATERAL FLORET 1 induced the three-florets spikelet in rice

2017 ◽  
Vol 114 (37) ◽  
pp. 9984-9989 ◽  
Author(s):  
Ting Zhang ◽  
Yunfeng Li ◽  
Ling Ma ◽  
Xianchun Sang ◽  
Yinghua Ling ◽  
...  
Keyword(s):  
Leucine Zipper ◽  
Molecular Mechanisms ◽  
Ectopic Expression ◽  
Target Sequence ◽  
Class Iii ◽  
Rice Mutant ◽  
Inflorescence Structure ◽  
Meristem Maintenance ◽  
Floral Meristems ◽  
Sterile Lemma

The spikelet is a unique inflorescence structure in grass. The molecular mechanisms behind the development and evolution of the spikelet are far from clear. In this study, a dominant rice mutant, lateral florets 1 (lf1), was characterized. In the lf1 spikelet, lateral floral meristems were promoted unexpectedly and could generally blossom into relatively normal florets. LF1 encoded a class III homeodomain-leucine zipper (HD-ZIP III) protein, and the site of mutation in lf1 was located in a putative miRNA165/166 target sequence. Ectopic expression of both LF1 and the meristem maintenance gene OSH1 was detected in the axil of the sterile lemma primordia of the lf1 spikelet. Furthermore, the promoter of OSH1 could be bound directly by LF1 protein. Collectively, these results indicate that the mutation of LF1 induces ectopic expression of OSH1, which results in the initiation of lateral meristems to generate lateral florets in the axil of the sterile lemma. This study thus offers strong evidence in support of the “three-florets spikelet” hypothesis in rice.

scholarly journals Evidence for habitual climbing in a Pleistocene hominin in South Africa

2020 ◽  
Vol 117 (15) ◽  
pp. 8416-8423 ◽  
Author(s):  
Leoni Georgiou ◽  
Christopher J. Dunmore ◽  
Ameline Bardo ◽  
Laura T. Buck ◽  
Jean-Jacques Hublin ◽  
...  
Keyword(s):  
South Africa ◽  
South African ◽  
Modern Human ◽  
Behavioral Differences ◽  
Terrestrial Environment ◽  
Present Evidence ◽  
Australopithecus Africanus ◽  
Locomotor Pattern ◽  
Morphological Adaptations ◽  
Morphological Differences

Bipedalism is a defining trait of the hominin lineage, associated with a transition from a more arboreal to a more terrestrial environment. While there is debate about when modern human-like bipedalism first appeared in hominins, all known South African hominins show morphological adaptations to bipedalism, suggesting that this was their predominant mode of locomotion. Here we present evidence that hominins preserved in the Sterkfontein Caves practiced two different locomotor repertoires. The trabecular structure of a proximal femur (StW 522) attributed to Australopithecus africanus exhibits a modern human-like bipedal locomotor pattern, while that of a geologically younger specimen (StW 311) attributed to either Homo sp. or Paranthropus robustus exhibits a pattern more similar to nonhuman apes, potentially suggesting regular bouts of both climbing and terrestrial bipedalism. Our results demonstrate distinct morphological differences, linked to behavioral differences between Australopithecus and later hominins in South Africa and contribute to the increasing evidence of locomotor diversity within the hominin clade.

TheHandlebarsgene is required withPhantasticafor dorsoventral asymmetry of organs and for stem cell activity inAntirrhinum

Development ◽  
2001 ◽  
Vol 128 (11) ◽  
pp. 1923-1931 ◽  
Author(s):  
Richard Waites ◽  
Andrew Hudson
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Genetic Analysis ◽  
Cell Activity ◽  
Vegetative Development ◽  
Dorsoventral Axis ◽  
Lateral Organs ◽  
Stem Cell Activity ◽  
Lateral Organ ◽  
Floral Meristems

In angiosperms, individual lateral organs and whole flowers may develop asymmetrically along their dorsoventral axes. Dorsoventral asymmetry of Antirrhinum leaves requires activity of the Phantastica gene and other factors acting redundantly with it. We describe the effects of a mutation in the Handlebars gene, identified as an enhancer of the phantastica mutant phenotype. Genetic analysis suggests that Handlebars functions redundantly with Phantastica to promote dorsal fate in lateral organs and to maintain activity of stem cells within shoot apical meristems. Handlebars appears dispensable in vegetative development but is needed for asymmetry of petals along the dorsoventral axis of the flower as a whole. This suggests that common mechanisms may control dorsoventral asymmetry in lateral organ primordia and in floral meristems.

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