Abstract
During phosphate starvation, plants alter membrane lipid composition; glycolipids increase in the membrane concomitantly with a reduction in phospholipids. We have shown that monogalactosyldiacylglycerol synthase genes, MGD2 and MGD3, are strongly induced upon phosphate starvation in Arabidopsis.
In this study, we carried out T-DNA-tagged mutant analyses in MGD2 and MGD3. Lipid analyses revealed that MGD3 was particularly important for the increase in galactolipid content during phosphate starvation while no mutation effect was observed under phosphate-sufficient condition. To investigate the effect of MGD2/3 mutation on phosphate-starved growth, phenotype analyses were performed in mgd2/3 under phosphate-starved condition. As a result, reduction in fresh weight, inhibition of root growth and a decrease in photosynthetic activity were observed in mgd2mgd3 double mutant, showing the requirement of MGD2/3 for phosphate-starved growth of Arabidopsis. Our data demonstrate that membrane lipid alteration is important for plants to adapt to phosphate starvation.
