Abstract
It has been known that water uptake of plant roots is depressed under hypoxia in hydroponics. In this study, lignification in hypoxic roots of cucumber plants was histochemically investigated. Cross sections of the secondary roots were treated with lignin-specific stain, phloroglucinol-HCI (Weisner reaction) . The cortical cell walls around the vascular cylinder were clearly stained in the hypoxic roots, but scarcely stained in the roots grown in well-aerated nutrient solution. From the fact, it is considered that lignification of the cortical cells around the vascular cylinder of the hypoxic roots may be one of the factors causing depressed water uptake.
