title: Pale-green phenotype of atl31atl6 double mutant leaves is caused by disruption of 5-aminolevulinic acid biosynthesis in Arabidopsis thaliana.
abstract: Arabidopsis ubiquitin ligases ATL31 and homologue ATL6 control the carbon/nitrogen nutrient and pathogen responses. A mutant with the loss-of-function of both atl31 and atl6 developed light intensity-dependent pale-green true leaves, whereas the single knockout mutants did not. Plastid ultrastructure and Blue Native-PAGE analyses revealed that pale-green leaves contain abnormal plastid structure with highly reduced levels of thylakoid proteins. In contrast, the pale-green leaves of the atl31/atl6 mutant showed normal Fv/Fm. In the pale-green leaves of the atl31/atl6, the expression of HEMA1, which encodes the key enzyme for 5-aminolevulinic acid synthesis, the rate-limiting step in chlorophyll biosynthesis, was markedly down-regulated. The expression of key transcription factor GLK1, which directly promotes HEMA1 transcription, was also significantly decreased in atl31/atl6 mutant. Finally, application of 5-aminolevulinic acid to the atl31/atl6 mutants resulted in recovery to a green phenotype. Taken together, these findings indicate that the 5-aminolevulinic acid biosynthesis step was inhibited through the down-regulation of chlorophyll biosynthesis-related genes in the pale-green leaves of atl31/atl6 mutant.
authors.affiliation: Faculty of Science and Graduate School of Life Science, Hokkaido University, Sapporo, Hokkaido, Japan.
authors.forename: Shugo
authors.initials: S
authors.lastname: Maekawa
authors.affiliation: Institute of Low Temperature Science, Hokkaido University, Sapporo, Hokkaido, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Takabayashi
authors.affiliation: Faculty of Science and Graduate School of Life Science, Hokkaido University, Sapporo, Hokkaido, Japan.
authors.forename: Thais
authors.initials: T
authors.lastname: Huarancca Reyes
authors.affiliation: Faculty of Science and Graduate School of Life Science, Hokkaido University, Sapporo, Hokkaido, Japan.
authors.forename: Hiroko
authors.initials: H
authors.lastname: Yamamoto
authors.affiliation: Institute of Low Temperature Science, Hokkaido University, Sapporo, Hokkaido, Japan.
authors.forename: Ayumi
authors.initials: A
authors.lastname: Tanaka
authors.affiliation: Faculty of Science and Graduate School of Life Science, Hokkaido University, Sapporo, Hokkaido, Japan.
authors.forename: Takeo
authors.initials: T
authors.lastname: Sato
authors.affiliation: Faculty of Science and Graduate School of Life Science, Hokkaido University, Sapporo, Hokkaido, Japan.
authors.forename: Junji
authors.initials: J
authors.lastname: Yamaguchi
mesh_terms: D000622:Aminolevulinic Acid / Q000378:metabolism*; D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics*; D002734:Chlorophyll / Q000235:genetics; D015536:Down-Regulation / Q000235:genetics; D018506:Gene Expression Regulation, Plant / Q000235:genetics; D009154:Mutation / Q000235:genetics*; D010641:Phenotype; D018515:Plant Leaves / Q000235:genetics* / Q000378:metabolism; D018087:Plastids / Q000235:genetics; D020524:Thylakoids / Q000235:genetics; D014157:Transcription Factors / Q000235:genetics; D014158:Transcription, Genetic / Q000235:genetics; D044767:Ubiquitin-Protein Ligases / Q000235:genetics*
chemical_list: D029681:Arabidopsis Proteins; D014157:Transcription Factors; D002734:Chlorophyll; D000622:Aminolevulinic Acid; C547213:ATL31 protein, Arabidopsis; D044767:Ubiquitin-Protein Ligases