亚铁胁迫对水稻生长及矿质元素积累的影响

Effects of Ferrous Toxicity on Growth of Rice and Accumulation of Some Mineral Elements in Rice Plants

亚铁胁迫导致植株生长发育受抑制,影响了水稻产量和稻米品质。因此,明确亚铁胁迫的分子与生理机制,对水稻耐受型亚铁品种的选育至关重要。本文选用对亚铁毒害有显著差异的10个籼型水稻品种为材料,通过亚铁毒害胁迫水培处理,研究亚铁毒害对不同基因型水稻生长与Zn、Mn、P、K、Mg、Ca等矿质元素积累的影响。结果表明,高浓度Fe^(2+)处理后,水稻株高、根长和植株(地上部和根系)干物质量均受到显著抑制,同时水稻植株叶片中叶绿素含量降低,SOD、CAT活性和MDA含量明显高于根系,根膜、根系和地上部中Fe元素含量明显增高,而根系和地上部中其他矿质元素含量则显著低于正常供铁植株。可见,过量的Fe^(2+)会对水稻产生毒害,导致植株中Zn、Mn、P、K、Mg、Ca等营养元素严重缺乏,影响植株的正常生长发育,进而影响稻米产量和品质。因此,铁毒害造成水稻植株缺乏其他营养进而影响其生长发育,是铁毒害作用的重要生理机制。

Iron toxicity is a major nutrient disorder affecting rice, it leads to the inhibition of plant growth and affects the yield and quality of rice. Therefore,understanding the genetic and physiological mechanisms associated with iron toxicity tolerance of rice is crucial in adaptive breeding. In this study, an experiment was conducted to study the effects of high iron stress on growth and nutrient elements in 10 kinds of genotypes rice with different iron tolerance plants, to understand the growth of different genotypes rice and effect of Zn, Mn, P, K, Mg, Ca mineral elements accumulation under the ferrous toxicity.The results showed that high iron stress significantly inhibited plant height, root length, dry weight of the plant（shoots and roots）in all the genotypes rice. Under excessive ferrous stress, chlorophyll content decreased in the leaves, SOD, CAT activities and MDA content in leaves were apparent higher than in root.Moreover, the iron content in iron plaque, roots and shoots remarkably increased, while other nutrients element in roots and shoots significantly decreased. In conclusion, Zn, Mn, P, K, Mg and Ca nutrients elements of all the genotypes rice were much lower than normal iron plants in shoots under high Fe2＋ concentration treatment, so the iron toxicity caused serious nutrition deficiencies in rice plants and affected the normal growth, and further influence the production and quality of rice. In summary, ferrous toxicity causes the other nutriment element lack in rice plants and then affect its growth and development, this is the important physiological mechanism of iron toxicity.