Sorghum Ionomics Reveals the Functional SbHMA3a Allele that Limits Excess Cadmium Accumulation in Grains.
Sorghum Ionomics Reveals the Functional SbHMA3a Allele that Limits Excess Cadmium Accumulation in Grains.
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高粱离子组学揭示了限制谷物中镉过量积累的功能性 SbHMA3a 等位基因。
DOI：
10.1093/pcp/pcac035
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发表时间：
2022
影响因子：
4.9
通讯作者：
Wataru Sakamoto
中科院分区：
文献类型：
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作者：
Fiona Wacera Wahinya;Kiyoshi Yamazaki;Zihuan Jing;Tsuneaki Takami;Takehiro Kamiya;Hiromi Kajiya-Kanegae;Hideki Takanashi;Hiroyoshi Iwata;Nobuhiro Tsutsumi;Toru Fujiwara;Wataru Sakamoto
了解必需矿物质的吸收和再分配或有毒元素的螯合对于优化作物生产非常重要。虽然控制矿物运输的机制已在水稻和其他物种中阐明，但对高粱-一种重要的C4谷类作物知之甚少。在这里，我们评估了遗传因素，支配谷物离子组配置文件在高粱中使用重组自交系（RILs）来自BTx 623和NOG（Takakibi）之间的杂交。在温室条件下收获的高粱籽粒中测量的22种元素的成对相关和聚类分析表明，亲本系以及RIL显示出不同的离子体。特别是，BTx 623积累了显着更高水平的镉（Cd）比NOG，因为两个线之间的差异根到地上部的易位因素。数量性状基因座（QTL）分析显示，一个显着的QTL籽粒镉浓度的第2染色体上。详细的分析鉴定SbHMA 3a，编码P1 B型ATP酶重金属转运蛋白，负责低镉积累的谷物; NOG等位基因编码的功能HMA 3转运蛋白（SbHMA 3a-NOG），其镉转运活性在酵母中的异源表达证实。BTx 623具有截短的、功能丧失的SbHMA 3a等位基因。SbHMA 3a在NOG中的功能性通过来自反交的F2籽粒的Cd浓度证实，其中NOG等位基因以显性方式表现。我们的结论是，SbHMA 3a-NOG是一个镉转运，螯合多余的镉在根组织中，如在其他HMA 3s。我们的研究结果将有利于分离育种品种与低镉的谷物或利用高镉品种的植物修复。
Understanding uptake and redistribution of essential minerals or sequestering of toxic elements is important for optimized crop production. Although the mechanisms controlling mineral transport have been elucidated in rice and other species, little is understood in sorghum—an important C4cereal crop. Here, we assessed the genetic factors that govern grain ionome profiles in sorghum using recombinant inbred lines (RILs) derived from a cross between BTx623 and NOG (Takakibi). Pairwise correlation and clustering analysis of 22 elements, measured in sorghum grains harvested under greenhouse conditions, indicated that the parental lines, as well as the RILs, show different ionomes. In particular, BTx623 accumulated significantly higher levels of cadmium (Cd) than NOG, because of differential root-to-shoot translocation factors between the two lines. Quantitative trait locus (QTL) analysis revealed a prominent QTL for grain Cd concentration on chromosome 2. Detailed analysis identifiedSbHMA3a, encoding a P1B-type ATPase heavy metal transporter, as responsible for low Cd accumulation in grains; the NOG allele encoded a functional HMA3 transporter (SbHMA3a-NOG) whose Cd-transporting activity was confirmed by heterologous expression in yeast. BTx623 possessed a truncated, loss-of-functionSbHMA3aallele. The functionality of SbHMA3a in NOG was confirmed by Cd concentrations of F2grains derived from the reciprocal cross, in which the NOG allele behaved in a dominant manner. We concluded that SbHMA3a-NOG is a Cd transporter that sequesters excess Cd in root tissues, as shown in other HMA3s. Our findings will facilitate the isolation of breeding cultivars with low Cd in grains or in exploiting high-Cd cultivars for phytoremediation.