GEPHE SUMMARY Print
Gephebase Gene
Entry Status
Published
GepheID
GP00002066
Main curator
Cao
PHENOTYPIC CHANGE
Trait #1
Trait Category
Trait State in Taxon A
Arabidopsis thaliana - normal growth at high ambient temperature (27–28C)
Trait State in Taxon B
Arabidopsis thaliana - aberrant growth at high ambient temperature; reduced growth; smaller; pale and serrated leaves with reduced expansion of the leaf blade; altered phyllotaxy; plant architecture and severely impaired seed production
Trait #2
Trait Category
Trait State in Taxon A
Arabidopsis thaliana - normal response to Bleomycin
Trait State in Taxon B
Arabidopsis thaliana - hypersensitive to Bleomycin, growth arrest of the first true leaves
Ancestral State
Taxon A
Taxonomic Status
Taxon A
Common Name
thale cress
Synonyms
thale cress; mouse-ear cress; thale-cress; Arabidopsis thaliana (L.) Heynh.; Arabidopsis thaliana (thale cress); Arabidopsis_thaliana; Arbisopsis thaliana; thale kress
Rank
species
Lineage
Show more ... ; Embryophyta; Tracheophyta; Euphyllophyta; Spermatophyta; Magnoliophyta; Mesangiospermae; eudicotyledons; Gunneridae; Pentapetalae; rosids; malvids; Brassicales; Brassicaceae; Camelineae; Arabidopsis
NCBI Taxonomy ID
is Taxon A an Infraspecies?
No
Taxon B
Common Name
thale cress
Synonyms
thale cress; mouse-ear cress; thale-cress; Arabidopsis thaliana (L.) Heynh.; Arabidopsis thaliana (thale cress); Arabidopsis_thaliana; Arbisopsis thaliana; thale kress
Rank
species
Lineage
Show more ... ; Embryophyta; Tracheophyta; Euphyllophyta; Spermatophyta; Magnoliophyta; Mesangiospermae; eudicotyledons; Gunneridae; Pentapetalae; rosids; malvids; Brassicales; Brassicaceae; Camelineae; Arabidopsis
NCBI Taxonomy ID
is Taxon B an Infraspecies?
No
GENOTYPIC CHANGE
UniProtKB
Arabidopsis thaliana
GenebankID or UniProtKB
Arabidopsis thaliana
Mutation #1
Presumptive Null
Yes
Molecular Type
Aberration Type
SNP
SNP Coding Change
Nonsynonymous
Molecular Details of the Mutation
ICARUS1 (ICA1) encodes a protein of the tRNA(His) guanylyl transferase (Thg1) superfamily. ICA1 loss-of-function results in down regulation of cell cycle associated genes at high temperatures, which is linked with a block in G2/M transition and endoreduplication; plants with mutations in ICA1 show enhanced sensitivity to DNA damage
Experimental Evidence
Taxon A Taxon B Position
Codon - - -
Amino-acid Ser Pro 81
Authors
Zhu W; Ausin I; Seleznev A; Méndez-Vigo B; Picó FX; Sureshkumar S; Sundaramoorthi V; Bulach D; et al. ... show more
Abstract
Plants are highly sensitive to environmental changes and even small variations in ambient temperature have severe consequences on their growth and development. Temperature affects multiple aspects of plant development, but the processes and mechanisms underlying thermo-sensitive growth responses are mostly unknown. Here we exploit natural variation in Arabidopsis thaliana to identify and characterize novel components and processes mediating thermo-sensitive growth responses in plants. Phenotypic screening of wild accessions identified several strains displaying pleiotropic growth defects, at cellular and organism levels, specifically at high ambient temperatures. Positional cloning and characterization of the underlying gene revealed that ICARUS1 (ICA1), which encodes a protein of the tRNAHis guanylyl transferase (Thg1) superfamily, is required for plant growth at high temperatures. Transcriptome and gene marker analyses together with DNA content measurements show that ICA1 loss-of-function results in down regulation of cell cycle associated genes at high temperatures, which is linked with a block in G2/M transition and endoreduplication. In addition, plants with mutations in ICA1 show enhanced sensitivity to DNA damage. Characterization of additional strains that carry lesions in ICA1, but display normal growth, shows that alternative splicing is likely to alleviate the deleterious effects of some natural mutations. Furthermore, analyses of worldwide and regional collections of natural accessions indicate that ICA1 loss-of-function has arisen several times independently, and that these occur at high frequency in some local populations. Overall our results suggest that ICA1-mediated-modulation of fundamental processes such as tRNAHis maturation, modify plant growth responses to temperature changes in a quantitative and reversible manner, in natural populations.
Additional References
Mutation #2
Presumptive Null
Yes
Molecular Type
Aberration Type
Deletion Size
1-9 bp
Molecular Details of the Mutation
This mutation (position T490*) is predicted to shift the reading frame and generate a short truncated protein of 31 amino acids. However mutations are suppressed by alternative splicing. Alternative splicing enables the natural intragenic suppression of an otherwise ICA1 loss-of-function allele.
Experimental Evidence
Authors
Zhu W; Ausin I; Seleznev A; Méndez-Vigo B; Picó FX; Sureshkumar S; Sundaramoorthi V; Bulach D; et al. ... show more
Abstract
Plants are highly sensitive to environmental changes and even small variations in ambient temperature have severe consequences on their growth and development. Temperature affects multiple aspects of plant development, but the processes and mechanisms underlying thermo-sensitive growth responses are mostly unknown. Here we exploit natural variation in Arabidopsis thaliana to identify and characterize novel components and processes mediating thermo-sensitive growth responses in plants. Phenotypic screening of wild accessions identified several strains displaying pleiotropic growth defects, at cellular and organism levels, specifically at high ambient temperatures. Positional cloning and characterization of the underlying gene revealed that ICARUS1 (ICA1), which encodes a protein of the tRNAHis guanylyl transferase (Thg1) superfamily, is required for plant growth at high temperatures. Transcriptome and gene marker analyses together with DNA content measurements show that ICA1 loss-of-function results in down regulation of cell cycle associated genes at high temperatures, which is linked with a block in G2/M transition and endoreduplication. In addition, plants with mutations in ICA1 show enhanced sensitivity to DNA damage. Characterization of additional strains that carry lesions in ICA1, but display normal growth, shows that alternative splicing is likely to alleviate the deleterious effects of some natural mutations. Furthermore, analyses of worldwide and regional collections of natural accessions indicate that ICA1 loss-of-function has arisen several times independently, and that these occur at high frequency in some local populations. Overall our results suggest that ICA1-mediated-modulation of fundamental processes such as tRNAHis maturation, modify plant growth responses to temperature changes in a quantitative and reversible manner, in natural populations.
Additional References
EXTERNAL LINKS
COMMENTS
@Splicing @Pleiotropy
YOUR FEEDBACK is welcome!