Arabidopsis thaliana FLO2 is Involved in Efficiency of Photoassimilate Translocation, Which is Associated with Leaf Growth and Aging, Yield of Seeds and Seed Quality.
FLO2, FLOURY ENDOSPERM 2, is highly conserved in higher plants, and rice FLO2 has been predicted to be involved in regulation of accumulation of storage compounds. We analyzed the function of Arabidopsis thaliana FLO2 (AtFLO2) because A. thaliana set structurally different seeds from those of rice. Although the flo2 mutant of A. thaliana showed normal germination, inflorescence and morphogenesis of flowers, peculiar phenotypes on leaves and siliques were observed, suggesting that this gene played important roles during both the vegetative and reproductive stages. The mutant leaves showed a decrease in chloroplast numbers, and increased total biomass with faster growth. When grown in high light intensity conditions, it was observed that aging events were induced. The flo2 mutant showed depressed transportation of photoassimilates into the sink organs. In the reproductive stage, the flo2 mutant had significantly smaller size siliques, causing a reduced yield of seeds. These seeds were structurally weak, and the quality of seeds was significantly lowered, with reduction of accumulation of storage compounds by seeds. A positron-emitting tracer imaging system (PETIS) analysis detected a decreased amount of photoassimilate transport in the flo2 mutant. Therefore, it was presumed that the phenotypes of the flo2 mutant were caused by reduced performance of translocation or transportation of the photoassimilates. Our observation suggests that AtFLO2 is strongly involved in regulation of translocation and transport of assimilates, and contributes greatly to quality control of the various processes involving substance supply or transfer, such as photoassimilation, leaf enlargement, yield of seeds in a silique and accumulation of seed storage compounds.
Department of Biological Science and Technology, Tokyo University of Science, Niijuku 6-3-1, Katsushika, Tokyo, 125-8585 Japan.
Miho
M
Kihira
Department of Biological Science and Technology, Tokyo University of Science, Niijuku 6-3-1, Katsushika, Tokyo, 125-8585 Japan.
Kazushi
K
Taniguchi
Department of Biological Science and Technology, Tokyo University of Science, Niijuku 6-3-1, Katsushika, Tokyo, 125-8585 Japan.
Chihiro
C
Kaneko
Department of Biological Science and Technology, Tokyo University of Science, Niijuku 6-3-1, Katsushika, Tokyo, 125-8585 Japan.
Yohei
Y
Ishii
Department of Biological Science and Technology, Tokyo University of Science, Niijuku 6-3-1, Katsushika, Tokyo, 125-8585 Japan.
Hiromi
H
Aoki
Department of Biological Science and Technology, Tokyo University of Science, Niijuku 6-3-1, Katsushika, Tokyo, 125-8585 Japan.
Atsushi
A
Koyanagi
Department of Biological Science and Technology, Tokyo University of Science, Niijuku 6-3-1, Katsushika, Tokyo, 125-8585 Japan.|Laboratory of Plant Gene Expression, Research Institute for Sustainable Humanosphere, Kyoto University, Gokasho, Ugi, 6110011, Japan.
Hiroaki
H
Kusano
Takasaki Advanced Radiation Research Institute, National Institutes for Quantum and Radiological Science and Technology, 1233 Watanuki, Takasaki, 370-1292 Japan.
Nobuo
N
Suzui
Takasaki Advanced Radiation Research Institute, National Institutes for Quantum and Radiological Science and Technology, 1233 Watanuki, Takasaki, 370-1292 Japan.
Yong-Gen
YG
Yin
Takasaki Advanced Radiation Research Institute, National Institutes for Quantum and Radiological Science and Technology, 1233 Watanuki, Takasaki, 370-1292 Japan.
Naoki
N
Kawachi
Takasaki Advanced Radiation Research Institute, National Institutes for Quantum and Radiological Science and Technology, 1233 Watanuki, Takasaki, 370-1292 Japan.|Department of Management and Planning, National Institutes for Quantum and Radiological Science and Technology, 4-9-1 Anagawa, Inage, Chiba, 263-8555 Japan.
Shu
S
Fujimaki
Department of Biological Science and Technology, Tokyo University of Science, Niijuku 6-3-1, Katsushika, Tokyo, 125-8585 Japan.
Hiroaki
H
Shimada
D000375:Aging; D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D018744:DNA, Plant / Q000235:genetics; D035264:Flowers; D018506:Gene Expression Regulation, Plant; D005838:Genotype; D018525:Germination; D026901:Membrane Transport Proteins / Q000235:genetics / Q000378:metabolism*; D009154:Mutation; D012275:Oryza / Q000235:genetics / Q000378:metabolism; D010641:Phenotype; D018515:Plant Leaves / Q000166:cytology / Q000254:growth & development* / Q000378:metabolism; D030821:Plants, Genetically Modified / Q000235:genetics / Q000378:metabolism; D055314:Seed Storage Proteins / Q000235:genetics / Q000378:metabolism; D012639:Seeds / Q000166:cytology / Q000235:genetics / Q000254:growth & development
D029681:Arabidopsis Proteins; D018744:DNA, Plant; D026901:Membrane Transport Proteins; D055314:Seed Storage Proteins
Accumulation of seed storage compounds; Arabidopsis thaliana; Early aging feature; Formation of small siliques; PETIS (positron-emitting tracer imaging system); Translocation of photoassimilates