Abstract
Meiotic recombination is the main driver of genetic diversity in wheat breeding. The rate and location of crossover (CO) events are regulated by genetic and epigenetic factors. In wheat, most COs occur in subtelomeric regions but are rare in centromeric and pericentric areas. The aim of this work was to increase COs in both “hot” and “cold” chromosomal locations. We used Virus-Induced gene Silencing (VIGS) to downregulate the expression of recombination-suppressing genes XRCC2 and FANCM and of epigenetic maintenance genes MET1 and DDM1 during meiosis. VIGS suppresses genes in a dominant, transient and non-transgenic manner, which is convenient in wheat, a hard-to-transform polyploid. F1 hybrids of a cross between two tetraploid lines whose genome was fully sequenced (wild emmer and durum wheat), were infected with a VIGS vector ∼ 2 weeks before meiosis. Recombination was measured in F2 seedlings derived from F1-infected plants and non-infected controls. We found significant up and down-regulation of CO rates along subtelomeric regions as a result of silencing either MET1, DDM1 or XRCC2 during meiosis. In addition, we found up to 93% increase in COs in XRCC2-VIGS treatment in the pericentric regions of some chromosomes. Silencing FANCM showed no effect on CO. Overall, we show that CO distribution was affected by VIGS treatments rather than the total number of COs which did not change. We conclude that transient silencing of specific genes during meiosis can be used as a simple, fast and non-transgenic strategy to improve breeding abilities in specific chromosomal regions.
| Original language | English |
|---|---|
| Article number | 635139 |
| Number of pages | 13 |
| Journal | Frontiers in Plant Science |
| Volume | 11 |
| DOIs | |
| Publication status | Published Online - 4 Feb 2021 |
Funding
We thank Asaf Distelfeld for providing Zavitan seeds and genomic data. We also thank Naomi Avivi-Ragolski for her help with wheat hybridization and to Prof. Moshe Feldman for his help with the cytological analysis. This research was supported by United States–Israel Binational Agricultural Research and Development Fund Grant US-4828-15 (to Wojciech P. Pawlowski and Avraham A. Levy) and also by the Sir Charles Clore Postdoctoral Fellowship for 2016–2017. Author contributions - AL and AR designed the research and wrote the manuscript. AR performed the research. DL did InDels analysis. TD-M helped with GBS calibration and data analysis. TD-M and CM-B helped with library preparation and NGS sequencing. All authors contributed to the article and approved the submitted version.
All Science Journal Classification (ASJC) codes
- Plant Science