Enhanced tolerance of rice to low iron availability in alkaline soils using barley nicotianamine aminotransferase genes
Enhanced tolerance of rice to low iron availability in alkaline soils using barley nicotianamine aminotransferase genes
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DOI：
10.1038/88143
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发表时间：
2001-05-01
影响因子：
46.9
通讯作者：
Mori, S
中科院分区：
文献类型：
--
作者：
Takahashi, M;Nakanishi, H;Mori, S
世界农业中范围最广的非生物胁迫之一是由于土壤pH值高而导致的铁（Fe）可用性低，其中30%的耕地碱性过高，无法进行最佳作物生产。水稻特别容易受到低铁供应的影响，而其他禾本科作物如大麦则不会。利用农杆菌介导法和pBIGRZ 1将含有两个naat基因的大麦基因组DNA片段导入水稻。植物铁载体是禾本科植物从根部分泌的天然铁螯合剂，用于溶解土壤中的铁。这两个转基因在水稻转化体的地上部和根中均表达，以响应低铁营养状况。表达这两个基因的转基因水稻表现出较高的烟酰胺氨基转移酶活性和分泌大量的植物铁载体比非转化体在缺铁条件下。因此，转基因水稻表现出对低铁有效性的耐受性增强，在碱性土壤中的籽粒产量是非水稻的4.1倍。
One of the widest ranging abiotic stresses in world agriculture arises from low iron (Fe) availability due to high soil pH, with 30% of arable land too alkaline for optimal crop production. Rice is especially susceptible to low iron supply, whereas other graminaceous crops such as barley are not. A barley genomic DNA fragment containing two naat genes, which encode crucial enzymes involved in the biosynthesis of phytosiderophores, was introduced into rice using Agrobacterium-mediated transformation and pBIGRZ1. Phytosiderophores are natural iron chelators that graminaceous plants secrete from their roots to solubilize iron in the soil. The two transgenes were expressed in response to low iron nutritional status in both the shoots and roots of rice transformants. Transgenic rice expressing the two genes showed a higher nicotianamine aminotransferase activity and secreted larger amounts of phytosiderophores than nontransformants under iron-deficient conditions. Consequently, the transgenic rice showed an enhanced tolerance to low iron availability and had 4.1 times greater grain yields than that of the nontransformant rice in an alkaline soil.