外源一氧化氮介导铜胁迫下番茄幼苗中铁、锌、锰的累积及亚细胞分布

采用营养液培养方法，以改良毛粉802F1番茄为材料， 研究外源一氧化氮（NO，SNP为供体）对铜（Cu）胁迫下番茄幼苗铁（Fe）、 锌（Zn）、 锰（Mn）吸收分配的影响。结果显示， 50 mol/ L的 Cu2+ 胁迫下，番茄幼苗的生物量和株高显著降低了33.7% 和23.1%，外施100 mol/L SNP可显著缓解这种抑制作用， 提高Cu 胁迫下番茄幼苗根系、 茎中Fe、 Mn含量及叶柄、 叶片中Fe、 Zn含量，降低茎中Zn含量及叶柄、 叶片中Mn含量; 根系、 茎、 叶柄、 叶片Fe、 Zn及根系和茎中Mn的累积相应增加; 根系吸收的Fe、 Zn、 Mn向地上部的转运降低。Cu 胁迫下， 外源NO可显著提高番茄液泡、 细胞器的Fe、 Zn 含量， 降低根系和叶片细胞壁Fe、 Zn、 Mn含量。在作为转运组织的茎和叶柄中，Mn主要分布在细胞壁上，而在叶柄和叶片液泡、 细胞器中也有增加。表明外源NO可以调控番茄幼苗各部位及亚细胞中Fe、 Zn、 Mn的合理分布，维持胞质离子稳态和矿质营养元素平衡，缓解铜胁迫，保证番茄幼苗正常的生理代谢。

Exogenous nitric oxide involved in the accumulation and subcellular distribution of Fe,Zn and Mn in tomato seedlings under copper stress

 A tomato cultivar,  Gailiang Maofen 802F1,  was selected as the planting material to investigate effects of NO on the absorption and distribution of Fe,  Zn and Mn in tomato seedlings under copper stress using nutrient solution cultivation in greenhouse. The results show that the biomass and plant height of tomato seedlings are decreased by 33.7% and 23.1% respectively under the 50 μmol/L copper stress,  while the addition of 100 μmol/L SNP could remarkably alleviate this inhibition effect. For mineral elements,  SNP could remarkably increase the Fe and Mn concentrations in roots and stems,  and Fe and Zn concentrations in petioles and leaves,  and the Zn concentration in stems and the Mn concentrations in petioles and leaves are reduced under the copper stress. Meanwhile the exogenous NO could improve Fe and Zn accumulation amounts in roots,  stems,  petioles and leaves and Mn accumulation amounts in roots and stems,  while the exogenous NO reduces the transformation of the absorbed Fe,  Zn and Mn red from roots to shoots. Under the Cu stress,  the exogenous NO could remarkably increase the Fe and Zn concentrations in vacuole and organelle of all organs and decrease Fe,  Zn and Mn concentrations in cell wall of roots and leaves. Mn mainly concentrates on the cell walls of stems and petioles that function as transport organizations,  while its concentrations in vacuole and organelle of petioles and leaves are also increased. These results suggest that the exogenous NO could effectively regulate Fe,  Zn and Mn rational distributions in organs and subcellular microzone under the Cu stress,  so that the seedlings could keep a better balance between mineral nutrition elements and intracellular ion homeostasis to maintain normal physiological metabolism of tomato.