不同铁形态对水稻根表铁膜及铁吸收的影响

Effect of different iron forms on iron plaque on root surface and iron uptake in rice seedlings

通过溶液培养试验研究了FeCl2.4H2O和FeCl3.6H2O对水稻根表铁膜数量及铁吸收的影响。结果表明,FeCl2处理时水稻根表铁膜浓度是FeCl3处理的197%～233%。利用EDTA-BPDS对铁膜形态分析看出,根表铁膜中Fe3+占85%～92%,Fe2+占8%～15%。水稻天优998(TY998)根表铁膜数量显著高于培杂泰丰(PZTF),其铁吸收是培杂泰丰的115%～138%。两种铁形态处理明显提高了水稻的根系活力,其中,FeCl2处理时水稻根系活力增加24%～69%,FeCl3为16%～54%。FeCl2处理时水稻根系SOD、POD和CAT活性分别增加11%～32%、15%～30%和30%～31%,但FeCl3处理没有明显影响。上述结果表明,一定浓度铁处理明显增加水稻根表铁浓度和铁吸收;与FeCl3处理相比,FeCl2处理能提高根系抗氧化酶活性,增加水稻的铁吸收和根表铁膜数量。

Iron forms have great impacts on iron nutrition of rice seedlings, however, it remains unclear on how different iron forms influence iron uptake in rice seedlings. In this study, a hydroponic experiment was conducted to investigate the effects of FeCl2 and FeCl3 on iron uptake and iron plaque in rice seedlings. Results showed that the concentration of iron plaque on root surface under FeCl2 treatment was 197%-233% of that under FeCl3 treatment. Fe3^＋ and Fe2^＋ consisted of 85%-92% and 8%-15% of the total iron plaque respectively. The concentration of iron plaque on the root surface of Tianyou 998 （ Oryza sativa L. cv. TY998 ） was significantly higher than that in Peizataifeng （Oryza sativa L. cv. PZTF）. Iron uptake in TY998 was 115%-138% of that in PZTF. Treatment with FeCl2 increased the activity of rice roots by 24%-69%, while FeCl3 treatment by 16%-54%. The activities of SOD,POD and CAT in rice roots were increased by 11%-32%, 15%-30% and 30%-31% respectively under FeCl2 treatment, while they did not change obviously under FeCl3 treatment. The above results suggested that the addition of a certain concentration of iron enhanced the formation of iron plaque on root surface and iron uptake in rice seedlings. In comparison to FeCl3 treatment, FeCl2 treatment was conductive to the increase of activities of antioxidant enzymes, thus improved iron uptake in rice seedlings.