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Transgenic expression of a putative calcium transporter affects the time of Arabidopsis flowering
Author(s) -
Wang Dayong,
Xu Yunjian,
Li Qing,
Hao Xuemei,
Cui Keming,
Sun Fangzhen,
Zhu Yuxian
Publication year - 2003
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1046/j.1365-313x.2003.01627.x
Subject(s) - arabidopsis , biology , chloroplast , transgene , calcium , microbiology and biotechnology , genetically modified crops , gibberellin , gene expression , gene , blot , botany , biochemistry , chemistry , mutant , organic chemistry
Summary PPF1 is a gibberellin‐induced, vegetative growth‐specific gene, first isolated from short‐day (SD)‐grown G2 pea plants. In the current work, we found that transgenic Arabidopsis plants overexpressing the PPF1 gene ( PPF1 (+)) flowered much later and had a significantly longer lifespan compared to control plants, whereas suppression of this gene ( PPF1 (–)) resulted in a very rapid reproductive cycle. Western blotting analyses of PPF1 (+) and (–) plant lines revealed a positive correlation between the amount of antibody‐reactive protein and the time of flowering. Green flourescent protein (GFP) co‐expression assays showed that the PPF1 protein is likely localized in chloroplast membranes. Transgenic expression of PPF1 affected the calcium storage capacities since chloroplasts isolated from PPF1 (+) plants contained high Ca 2+ levels while chloroplasts of PPF1 (–) plants contained very low amounts of calcium ion. Using Novikoff human hepatoma cells, we demonstrated that expression of PPF1 leads to a significant inward calcium ion current that was absent in untransformed cells. We conclude that, as a putative calcium ion carrier, PPF1 affects the flowering time of higher plants by modulating Ca 2+ storage capacity within chloroplasts.