Natural variation in a molybdate transporter controls grain molybdenum concentration in rice
Natural variation in a molybdate transporter controls grain molybdenum concentration in rice
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DOI：
10.1111/nph.15546
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发表时间：
2019-03-01
期刊：
影响因子：
9.4
通讯作者：
Salt, David E.
中科院分区：
文献类型：
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作者：
Huang, Xin-Yuan;Liu, Huan;Salt, David E.
钼（Mo）是大多数生物体（包括人类）必需的微量营养素。谷物如水稻（Oryza sativa）是钼的主要膳食来源。然而，水稻籽粒钼含量变异的遗传基础却知之甚少。利用重组自交系群体和回交导入系群体定位了控制水稻籽粒钼积累的数量性状位点qGMo 8。我们确定了一个α-淀粉酶转运蛋白，OsMOT 1;1，作为该QTL的致病基因。OsMOT 1;1在酵母细胞中异源表达时，表现出对硫酸盐的转运活性，但对硫酸盐没有转运活性。OsMOT 1;1主要在根中表达，在限制根的条件下参与植物对外源激素的吸收和转运。OsMOT 1;1基因的敲除导致Mo向地上部的转运减少，籽粒中Mo含量降低，对缺Mo的敏感性提高。我们揭示了水稻籽粒中钼浓度的自然变化归因于OsMOT 1;1的可变表达，由于其启动子的序列变异。OsMOT 1;1基因自然等位变异的鉴定有助于培育富钼水稻品种，改善缺钼土壤水稻的钼营养状况。
Molybdenum (Mo) is an essential micronutrient for most living organisms, including humans. Cereals such as rice (Oryza sativa) are the major dietary source of Mo. However, little is known about the genetic basis of the variation in Mo content in rice grain. We mapped a quantitative trait locus (QTL) qGMo8 that controls Mo accumulation in rice grain by using a recombinant inbred line population and a backcross introgression line population. We identified a molybdate transporter, OsMOT1;1, as the causal gene for this QTL. OsMOT1;1 exhibits transport activity for molybdate, but not sulfate, when heterogeneously expressed in yeast cells. OsMOT1;1 is mainly expressed in roots and is involved in the uptake and translocation of molybdate under molybdate-limited condition. Knockdown of OsMOT1;1 results in less Mo being translocated to shoots, lower Mo concentration in grains and higher sensitivity to Mo deficiency. We reveal that the natural variation of Mo concentration in rice grains is attributed to the variable expression of OsMOT1;1 due to sequence variation in its promoter. Identification of natural allelic variation in OsMOT1;1 may facilitate the development of rice varieties with Mo-enriched grain for dietary needs and improve Mo nutrition of rice on Mo-deficient soils.