ACCUMULATION AND DEPLETION OF APOPLASTIC IRON IN ROOTS OF TWO PEA GENOTYPES

Two pea genotypes were used to study accumulation and depletion of apolastic iron in roots The plants were grown in controlled conditions with 14/10 h light/dark, 20/15℃ day/night 1.0 mmol/L FeEDTA was supplied the 9th day after transplanting(DAT), and at the 12th DAT iron was removed Iron reducing activity and apoplastic iron in roots were measured during this period of time The results showed that apoplastic iron increased quickly in roots of both genotypes after FeEDTA was applied Within 4 h after iron supply Sparkle and E107 plants accumulated approximately 60%～80% of their maximum amount of apoplastic iron in roots There was no difference in the quantity of apoplastic iron accumulated in roots between the two genotypes of different iron efficiency E107 consumed apoplastic iron in roots more efficiently than Sparkle Four days after suspending iron supply (16th DAT), there were about 120 and 300nmolg-1 FW of apoplastic iron left, 150 and 20nmolg-1 FW h-1 of iron reducing activity in roots of E107 and Sparke plants respectively This suggested that depletion of apoplastic iron in roots was according with the strength of root responses to iron deficiency