Ma Meng, Zhong Wenying, Zhang Qing, Deng Li, Wen Jing, Yi Bin, Tu Jinxing, Fu Tingdong, Zhao Lun, Shen Jinxiong
National Key Laboratory of Crop Genetic Improvement, Hubei Hongshan Laboratory, National Center of Rapeseed Improvement in Wuhan, Huazhong Agricultural University, Wuhan, China.
Front Plant Sci. 2023 Jan 27;14:1123729. doi: 10.3389/fpls.2023.1123729. eCollection 2023.
Although utilization of heterosis has largely improved the yield of many crops worldwide, the underlying molecular mechanism of heterosis, particularly for allopolyploids, remains unclear. Here, we compared epigenome and transcriptome data of an elite hybrid and its parental lines in three assessed tissues (seedling, flower bud, and silique) to explore their contribution to heterosis in allopolyploid . Transcriptome analysis illustrated that a small proportion of non-additive genes in the hybrid compared with its parents, as well as parental expression level dominance, might have a significant effect on heterosis. We identified histone modification (H3K4me3 and H3K27me3) variation between the parents and hybrid, most of which resulted from the differences between parents. H3K4me3 variations were positively correlated with gene expression differences among the hybrid and its parents. Furthermore, H3K4me3 and H3K27me3 were rather stable in hybridization and were mainly inherited additively in the hybrid. Together, our data revealed that transcriptome reprogramming and histone modification remodeling in the hybrid could serve as valuable resources for better understanding heterosis in allopolyploid crops.
尽管杂种优势的利用在很大程度上提高了全球许多作物的产量，但杂种优势的潜在分子机制，尤其是异源多倍体的杂种优势分子机制仍不清楚。在此，我们比较了一个优良杂交种及其亲本系在三个评估组织（幼苗、花芽和角果）中的表观基因组和转录组数据，以探究它们对异源多倍体杂种优势的贡献。转录组分析表明，与亲本相比，杂交种中一小部分非加性基因以及亲本表达水平优势可能对杂种优势有显著影响。我们鉴定了亲本与杂交种之间的组蛋白修饰（H3K4me3和H3K27me3）变异，其中大部分是由亲本之间的差异导致的。H3K4me3变异与杂交种及其亲本之间的基因表达差异呈正相关。此外，H3K4me3和H3K27me3在杂交过程中相当稳定，并且在杂交种中主要以加性方式遗传。总之，我们的数据表明，杂交种中的转录组重编程和组蛋白修饰重塑可为更好地理解异源多倍体作物的杂种优势提供有价值的资源。
