外源NO对缺镁胁迫下玉米幼苗生长和离子平衡的影响

研究了在缺镁胁迫下,外源NO对缺镁玉米幼苗生长、根系活力和离子含量的影响。结果表明,缺镁胁迫使玉米幼苗株高、根长和干鲜重下降,根系活力降低,N元素在地上部和根部分配失调,新叶和老叶中Mg2＋、Cu2＋、Fe3＋、Mn2＋等离子含量下降,Ca2＋、K＋、Zn2＋等离子含量上升。根中Mg2＋离子含量下降,Ca2＋、K＋、Zn2＋、Cu2＋、Fe3＋、Mn2＋等离子含量上升。用100μmol·L-1一氧化氮供体硝普钠（SNP）处理后,玉米幼苗株高、根长、干重和鲜重均提高,根系活力增强,改善了N代谢,新叶中Ca2＋、K＋和Zn2＋等离子含量下降,Mg2＋、Cu2＋、Fe3＋和Mn2＋等离子含量提高,老叶中Mg2＋、Ca2＋、K＋和Zn2＋等离子含量下降,Cu2＋、Fe3＋和Mn2＋等离子含量提高,根中Mg2＋、Ca2＋、K＋、Cu2＋、Zn2＋、Fe3＋和Mn2＋离子含量均下降。实验结果表明,NO保护玉米幼苗免受缺镁胁迫的影响。

Effects of Exogenous Nitric Oxide on the Growth and Ion Homeostasis of Maize （Zea mays L.） Seedlings under Magnesium Deficient Stress

Effects of exogenous nitric oxide （NO） on the growth,root activity and some inorganic ions changes of maize seedlings under magenesium deficient stress were investigated.The results showed that the shoot and root length,fresh and dry weight of maize seedlings were reduced under magnesium deficient stress.The root activity was reduced under magnesium deficiency,either.The distribution of nitrogen in shoot and root was interfered under magnesium deficiency stress.The contents of inorganic ions such as Mg2＋,Cu2＋,Fe3＋ and Mn2＋ in younger and older leaves of maize subjected to magnesium deficiency were decreased while those of Ca2＋,K＋ and Zn2＋ increased.Magnesium content in root of maize seedlings was decreased under Mg deficient condition,but the contents of Ca2＋,K＋,Zn2＋,Cu2＋,Fe3＋ and Mn2＋ were increased.In comparison with magnesium deficient stress,the shoot length,root length,fresh weigth and dry weight of maize seedlings treated with 100 μmol·L-1 sodium nitroprusside （SNP）,an nitric oxide donor,was increased.The root activity was increased due to SNP treatment,either.The distribution and partition of N was rationalized in shoot and root.The contents of Mg2＋,Cu2＋,Fe3＋ and Mn2＋ in younger leaves and those of Cu2＋,Fe3＋ and Mn2＋ in older leaves were increased due to SNP treatment.Whereas the contents of Ca2＋,K＋ and Zn2＋ in younger leaves and Mg2＋,Ca2＋,K＋ and Zn2＋ in older leaves were decreased under SNP treatment condition.Contents of all of the ions were decreased in roots of magnesium deficient maize seedlings due to SNP treatment.The results obtained showed that NO protected maize seedlings from magnesium deficiency stress.