Molecular Evolution and Association of Natural Variation in ZmARF31 with Low Phosphorus Tolerance in Maize.
Molecular Evolution and Association of Natural Variation in ZmARF31 with Low Phosphorus Tolerance in Maize.
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ZmARF31 的分子进化以及自然变异与玉米低磷耐受性的关联
DOI：
10.3389/fpls.2016.01076
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发表时间：
2016
影响因子：
5.6
通讯作者：
Lu Y
中科院分区：
文献类型：
--
作者：
Wu F;Liu Z;Xu J;Gao S;Lin H;Liu L;Liu Y;Lu Y
低磷胁迫是制约植物生长和产量的主要因素之一。通过分子育种提高植物对磷饥饿的耐受性是提高粮食产量的有效途径。本研究以331个不同的玉米自交系为材料，检测了ZmARF31的核苷酸多样性和有利等位基因，该基因在低磷反应和根系构型调控中起着关键作用。在331份玉米自交系中，ZmARF31共检测到30个单核苷酸多态(SNPs)和14个插入缺失(Indels)。在显著的纯化选择下，ZmARF31的5‘-非翻译区(UTR)表现出较小的连锁不平衡(LD)块，而3’-UTR表现出最丰富的多样性和较大的LD块。用普通线性模型、结合群体结构的广义线性模型和混合线性模型分别鉴定出与耐低磷性状相关的自然变异(P≤0.0 1)有3 0个、14个和9个。在3个模型中，有4个SNP与总干重(TDW)显著相关，其中S410和S462位于一个完整的LD区块。在重组自交系群体中的进一步验证表明，非同义突变S410的有利等位基因G/G和插入38个碱基的有利等位基因Indel S1442分别对TDW和总根尖有正遗传效应。表达分析进一步证实，ZmARF31在耐低磷自交系178的根中高度表达。ZmARF31编码的蛋白质位于胞核和胞浆中。携带较多有利等位基因的单倍型对表型变异的影响大于单基因座。这些单倍型将有助于开发有价值的遗传标记和进行玉米分子育种。
Low-phosphorus (P) stress is one of the major factors constraining plant growth and yield. Improving plant tolerance to P starvation through molecular breeding is an efficient alternative to increase grain production. In the study, 331 diverse maize inbreds were used to detect nucleotide diversity and favorable alleles of ZmARF31, which plays a key role in low P responses and root architecture regulation. Significant phenotypic variation was found in each of 11 tested traits under both P and no-P treatments, and 30 single nucleotide polymorphisms (SNPs) and 14 insertion–deletions (InDels) were detected in ZmARF31 among the 331 maize inbreds. The 5′-untranslated region (UTR) of ZmARF31 showed a small linkage disequilibrium (LD) block under significant purifying selection, whereas the 3′-UTR showed the most abundant diversity and a larger LD block. Thirty, fourteen, and nine natural variations were identified in ZmARF31 that were associated with P-deficiency-tolerance traits (P ≤ 0.01) by using the general linear model (GLM), GLM incorporated with population structure, and mixed linear model, respectively. Four SNPs were significantly associated with the total dry weight (TDW) in the three models, of which SNPs S410 and S462 were located in a complete LD block. A further verification conducted in a recombinant inbred line population revealed that favorable allele G/G of non-synonymous mutation S410 and favorable allele with a 38 bp insertion of InDel S1442 exhibited positive genetic effects on the TDW and total root tips, respectively. Expression analysis further confirmed that ZmARF31 was highly expressed in the roots of low-P-tolerant inbred 178. The protein encoded by ZmARF31 was located both in the nucleus and cytoplasm. Haplotypes carrying more favorable alleles showed a greater effect on phenotypic variation than single loci. Such haplotypes should be helpful to develop valuable genetic markers and perform maize molecular breeding.