Effect of Vapour Pressure Deficit on Iron Exclusion in Rice Genotypes

Root iron (Fe) exclusion in rice is considered as a strategy of iron toxicity tolerance in lowland rice. Two lowland rice genotypes with contrasting responses to Fe²⁺ stress in hydroponics were evaluated in green house condition. Plants were subjected to the four levels of Fe stresses (0, 500, 1000 and 1500 mg Fe²⁺ L^-1) for four days under conditions of low and high vapor pressure deficit. Irrespective of rice genotypes, lower levels of Fe stresses stimulated the ischolar_main Fe oxidation. It, however, declined at higher rates of Fe stresses. Dry atmospheric significantly enhanced the ischolar_main Fe exclusion. Rice ischolar_main excluded on average of 114 mg Fe g^-1 ischolar_main dry matter when rice was grown in a moist atmosphere and exceeded 671 mg Fe g^-1 ischolar_main dry matter in the dry atmosphere.