Dual effect of the wheat Ph1 locus on chromosome synapsis and crossover

Allopolyploids must possess a mechanism for facilitating synapsis and crossover (CO) between homologues, in preference to homoeologues (related chromosomes), to ensure successful meiosis. In hexaploid wheat, the Ph1 locus has a major effect on the control of these processes. Studying a wheat mutant lacking Ph1 provides an opportunity to explore the underlying mechanisms. Recently, it was proposed that Ph1 stabilises wheat during meiosis, both by promoting homologue synapsis during early meiosis and preventing MLH1 sites on synapsed homoeologues from becoming COs later in meiosis. Here, we explore these two effects and demonstrate firstly that whether or not Ph1 is present, synapsis between homoeologues does not take place during the telomere bouquet stage, with only homologous synapsis taking place during this stage. Furthermore, in wheat lacking Ph1, overall synapsis is delayed with respect to the telomere bouquet, with more synapsis occurring after the bouquet stage, when homoeologous synapsis is also possible. Secondly, we show that in the absence of Ph1, we can increase the number of MLH1 sites progressing to COs by altering environmental growing conditions; we show that higher nutrient levels in the soil or lower temperatures increase the level of both homologue and homoeologue COs. These observations suggest opportunities to improve the exploitation of the Ph1 wheat mutant in breeding programmes.

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Author Martín, Azahara C.
Last Updated August 7, 2019, 10:54 (UTC)
Created July 31, 2019, 16:29 (UTC)
Article Host Type publisher
Article Is Open Access true
Article License Type cc-by
Article Version Type publishedVersion
Citation Report https://scite.ai/reports/10.1007/s00412-017-0630-0
DFW Organisation JIC
DFW Work Package 1
DOI 10.1007/s00412-017-0630-0
Date Last Updated 2019-01-02T04:30:24.001297
Evidence open (via page says license)
Journal Is Open Access false
Open Access Status hybrid
PDF URL https://link.springer.com/content/pdf/10.1007%2Fs00412-017-0630-0.pdf
Publisher URL https://doi.org/10.1007/s00412-017-0630-0