抄録
Cold deacclimation (DA) is a phenomenon that is genetically controlled to lose the degree of freezing resistance acquired during cold acclimation (CA). DA is also accompanied by a restart of plant growth arrested during CA, which may provide us with a suitable experimental system for studying the regulation of plant growth at molecular level. We herein identified a cDNA for putative myo-inositol oxygenase of Arabidopsis (AtMIOX), which exhibited a significant homology to hog MIOX and was induced by DA treatment. AtMIOX is hypothesized to oxygenize myo-inositol to D-glucuronate, which in turn may serve as a precursors to matrix polysaccharides (Seitz et al. (2000) Plant J. 21: 537-546). Alternatively, myo-inositol accumulated during CA might be oxygenized for respiratory substrates during DA. Experiments were conducted to test these possibilities, and a probable function of AtMIOX in the biosynthesis of matrix polysaccharides will be discussed. (Supported in part by a grant from PROBRAIN.)
