The KL system in wheat permits homoeologous crossing over between closely related chromosomes
The KL system in wheat permits homoeologous crossing over between closely related chromosomes
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DOI：
10.1016/j.cj.2023.01.003
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发表时间：
2023-06-01
期刊：
影响因子：
6.6
通讯作者：
Hao，Ming
中科院分区：
文献类型：
--
作者：
Fan，Chaolan;Luo，Jiangtao;Hao，Ming
中国小麦地方品种开县洛汉麦(KL)表现出类似ph的表型。与此相关的一个主效QTL QPh.sicau-3A(syn.phKL)已定位在染色体臂3AL上。本研究揭示了phKL诱导的同源配对和重组的一些特征。在KL单倍体中，同源配对水平高于Ph1中国春(CS)单倍体。A-D配对有明显的偏好，而A-B和B-D配对的频率较低，反映了小麦基因组A和D之间较高的亲和力。配对特性受温度和镁离子添加的影响。在2Sv-2B、2Sv-2D和2RL-2BL三对同源物上验证了phKL在染色体工程中的适用性。重组率分别为1.68%、0.17%和0%。在小麦单倍体和六倍体中，当存在小麦的Ph1基因座时，KL中的phKL基因座诱导了中等水平的同源染色体配对和重组。Ph1强加的染色体配对和交换的标准在一定程度上得到了放松，允许同源交换，但只允许在密切相关的染色体之间交换；在分化程度更高的染色体之间没有交换。因此，phKL系统(QPh.sicau-3A)可以作为一种有用的工具用于小麦染色体工程，以减少由ph1突变引起的基因组混乱，从而转移来自密切相关物种的基因。
The Chinese wheat landrace Kaixianluohanmai (KL) expresses theph-like phenotype. A major QTL,QPh.sicau-3A(syn.phKL), responsible for this effect has been mapped to chromosome arm 3AL. This study presents some characteristics of homoeologous pairing and recombination induced byphKL. In KL haploids, the level of homoeologous pairing was elevated relative toPh1Chinese Spring (CS) haploids. There was a clear preference for A–D pairing and less frequent for A–B and B–D, reflecting the higher levels of affinity between genomes A and D in wheat. The characteristics of pairing were affected by temperature and magnesium ion supplementation. The suitability ofphKLfor chromosome engineering was tested on three pairs of homoeologues: 2Sv-2B, 2Sv-2D, and 2RL-2BL. The recombination rates were 1.68%, 0.17%, and 0%, respectively. ThephKLlocus in KL induced a moderate level of homoeologous chromosome pairing and recombination when thePh1locus of wheat was present, both in wheat haploids and hexaploids. ThePh1-imposed criteria for chromosome pairing and crossing over were relaxed to some degree, permitting homoeologous crossing over but only between closely related chromosomes; there was no crossing over between more differentiated chromosomes. Therefore, thephKLsystem (QPh.sicau-3A) can be a useful tool in chromosome engineering of wheat to transfer genes from closely related species with the benefit of reduced genomic chaos generated by theph1bmutation.