The wheat Phs-A1 pre-harvest sprouting resistance locus delays the rate of seed dormancy loss and maps 0.3 cM distal to the PM19 genes in UK germplasm.
The wheat Phs-A1 pre-harvest sprouting resistance locus delays the rate of seed dormancy loss and maps 0.3 cM distal to the PM19 genes in UK germplasm.
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DOI：
10.1093/jxb/erw194
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发表时间：
2016-07
影响因子：
6.9
通讯作者：
Uauy C
中科院分区：
文献类型：
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作者：
Shorinola O;Bird N;Simmonds J;Berry S;Henriksson T;Jack P;Werner P;Gerjets T;Scholefield D;Balcárková B;Valárik M;Holdsworth MJ;Flintham J;Uauy C
Phs-A1 通过延迟种子休眠丧失的速度来赋予小麦抗发芽能力，并且与之前提出的 PM19 候选基因不同。谷物收获前的早发芽，又称收获前发芽，是谷物生产中产量和品质损失的重要根源。收获前发芽是一种复杂的谷物缺陷，并且由于气候模式的变化而成为越来越大的挑战。尽管现代小麦品种的发芽变异很大一部分是由几个主要数量性状基因座控制的，包括染色体臂4AL中的Phs-A1，但发芽抗性是多基因的。尽管它很重要，但人们对这个重要基因座的生理基础和基因知之甚少。在这项研究中，我们对 Phs-A1 进行了表征，并表明它通过影响干种子后熟过程中休眠丧失的速度来抵抗发芽损伤。我们证明，即使种子在低温（13°C）下发育，Phs-A1 仍然有效。对小麦和短柄草同线性 Phs-A1 区间的比较分析发现了 10 个直系同源基因，包括先前提出作为该基因座的主要候选基因的质膜 19 基因（PM19-A1 和 PM19-A2）。然而，两个双亲英国作图群体的高分辨率精细作图将 Phs-A1 限制在 PM19 基因远端 0.3 cM 的区间。这项研究表明，这一主要收获前发芽位点可能有不止一个因果基因。本研究报告的信息和资源将有助于在更广泛的种质中检验这一假设，并且对于培育更具发芽弹性的小麦品种具有重要意义。
Phs-A1 confers resistance to sprouting in wheat by delaying the rate of seed dormancy loss and is distinct from the previously proposed PM19 candidate genes. The precocious germination of cereal grains before harvest, also known as pre-harvest sprouting, is an important source of yield and quality loss in cereal production. Pre-harvest sprouting is a complex grain defect and is becoming an increasing challenge due to changing climate patterns. Resistance to sprouting is multi-genic, although a significant proportion of the sprouting variation in modern wheat cultivars is controlled by a few major quantitative trait loci, including Phs-A1 in chromosome arm 4AL. Despite its importance, little is known about the physiological basis and the gene(s) underlying this important locus. In this study, we characterized Phs-A1 and show that it confers resistance to sprouting damage by affecting the rate of dormancy loss during dry seed after-ripening. We show Phs-A1 to be effective even when seeds develop at low temperature (13 °C). Comparative analysis of syntenic Phs-A1 intervals in wheat and Brachypodium uncovered ten orthologous genes, including the Plasma Membrane 19 genes (PM19-A1 and PM19-A2) previously proposed as the main candidates for this locus. However, high-resolution fine-mapping in two bi-parental UK mapping populations delimited Phs-A1 to an interval 0.3 cM distal to the PM19 genes. This study suggests the possibility that more than one causal gene underlies this major pre-harvest sprouting locus. The information and resources reported in this study will help test this hypothesis across a wider set of germplasm and will be of importance for breeding more sprouting resilient wheat varieties.