Data_Sheet_1_Wheat-Thinopyrum Substitution Lines Imprint Compensation Both From Recipients and Donors.xlsx

Even frequently used in wheat breeding, we still have an insufficient understanding of the biology of the products via distant hybridization. In this study, a transcriptomic analysis was performed for six Triticum aestivum-Thinopyrum elongatum substitution lines in comparison with the host plants. All the six disomic substitution lines showed much stronger “transcriptomic-shock” occurred on alien genomes with 57.43–69.22% genes changed expression level but less on the recipient genome (2.19–8.97%). Genome-wide suppression of alien genes along chromosomes was observed with a high proportion of downregulated genes (39.69–48.21%). Oppositely, the wheat recipient showed genome-wide compensation with more upregulated genes, occurring on all chromosomes but not limited to the homeologous groups. Moreover, strong co-upregulation of the orthologs between wheat and Thinopyrum sub-genomes was enriched in photosynthesis with predicted chloroplastic localization, which indicates that the compensation happened not only on wheat host genomes but also on alien genomes.

尽管远缘杂交已广泛应用于小麦育种实践，但学界对该技术所获后代的生物学特性仍缺乏充分认知。本研究以6个普通小麦（Triticum aestivum）-长穗偃麦草（Thinopyrum elongatum）二体代换系（disomic substitution lines）及其受体亲本为材料，开展转录组学分析。结果显示，6个二体代换系的外源基因组均呈现出更为显著的“转录组冲击（transcriptomic-shock）”现象：约57.43%~69.22%的基因表达水平发生改变，而受体小麦基因组的基因表达变化比例仅为2.19%~8.97%。在外源基因组中，全染色体范围的基因表达抑制现象显著，下调基因占比达39.69%~48.21%。与之相反，受体小麦基因组则呈现全基因组补偿效应，上调基因占比更高，且该补偿现象遍布所有染色体，并不局限于部分同源群。此外，小麦与长穗偃麦草亚基因组间的直系同源基因（orthologs）协同上调现象显著富集于光合作用通路，且预测其定位于叶绿体中，这表明补偿效应不仅发生在小麦受体基因组，同样也存在于外源基因组中。