National Key Laboratory of Crop Genetics and Germplasm Enhancement Nanjing Agricultural University Nanjing 210095 China.
Hainan Key Laboratory for Biosafety Monitoring and Molecular Breeding in Off-Season Reproduction Regions Institute of Tropical Bioscience and Biotechnology Chinese Academy of Tropical Agricultural Sciences Haikou 571101 China.
Adv Sci (Weinh). 2021 Feb 15;8(9):2004222. doi: 10.1002/advs.202004222. eCollection 2021 May.
The importance of allopolyploidy in plant evolution has been widely recognized. The genetic changes triggered by allopolyploidy, however, are not yet fully understood due to inconsistent phenomena reported across diverse species. The construction of synthetic polyploids offers a controlled approach to systematically reveal genomic changes that occur during the process of polyploidy. This study reports the first fully sequenced synthetic allopolyploid constructed from a cross between and , with high-quality assembly. The two subgenomes are confidently partitioned and the -originated subgenome predominates over the -originated subgenome, retaining more sequences and showing higher homeologous gene expression. Most of the genomic changes emerge immediately after interspecific hybridization. Analysis of a series of genome sequences from several generations (S, S-S) of . × confirms that genomic changes occurred in the very first generations, subsequently slowing down as the process of diploidization is initiated. The duplicated genome of the allopolyploid with double genes from both parents broadens the genetic base of . ×, resulting in enhanced phenotypic plasticity. This study provides novel insights into plant polyploid genome evolution and demonstrates a promising strategy for the development of a wide array of novel plant species and varieties through artificial polyploidization.
异源多倍体在植物进化中的重要性已得到广泛认可。然而，由于不同物种报道的现象不一致，异源多倍体引发的遗传变化仍未被完全理解。人工合成多倍体的构建提供了一种系统揭示多倍体过程中发生的基因组变化的受控方法。本研究报道了首例由 和 杂交构建的完全测序的异源合成多倍体，具有高质量的组装。两个亚基因组被明确划分，起源于 的亚基因组占主导地位，保留了更多的序列，并表现出更高的同源基因表达。大多数基因组变化在种间杂交后立即出现。对来自 × 几个世代（S、S-S）的一系列基因组序列的分析证实，基因组变化发生在第一代，随后随着二倍化过程的启动而减缓。异源多倍体的加倍基因组具有来自双亲的双倍基因，拓宽了 × 的遗传基础，导致表型可塑性增强。本研究为植物多倍体基因组进化提供了新的见解，并展示了通过人工多倍体化开发广泛新型植物物种和品种的有前途的策略。
