Genome shock in a synthetic allotetraploid wheat invokes subgenome-partitioned gene regulation, meiotic instability, and karyotype variation

作者：Yan Sha, Yang Li, Deshi Zhang, Ruili Lv, Han Wang, Ruisi Wang, Heyu Ji, Shuhang Li, Lei Gong, Ning Li, Liu B · 发表于：Journal of Experimental Botany · 年份：2023 · DOI：10.1093/jxb/erad247 · 被引用次数：8 · 研究领域：Chromosomal and Genetic Variations、Wheat and Barley Genetics and Pathology、Genetic Mapping and Diversity in Plants and Animals

It is becoming increasingly evident that interspecific hybridization at the homoploid level or coupled with whole-genome duplication (i.e. allopolyploidization) has played a major role in biological evolution. However, the direct impacts of hybridization and allopolyploidization on genome structure and function, phenotype, and fitness remains to be fully understood. Synthetic hybrids and allopolyploids are trackable experimental systems that can be used to address this issue. In this study, we resynthesized a pair of reciprocal F1 hybrids and corresponding reciprocal allotetraploids using the two diploid progenitor species of bread wheat (Triticum aestivum, BBAADD), namely T. urartu (AA) and Aegilops tauschii (DD). By comparing phenotypes related to growth, development, and fitness, and by analysing genome expression in both hybrids and allotetraploids in relation to the parents, we found that the types and trends of karyotype variation in the immediately formed allotetraploids were correlated with both instability of meiosis and chromosome- and subgenome-biased expression. We determined clear advantages of allotetraploids over diploid F1 hybrids in several morphological traits including fitness that mirrored the tissue- and developmental stage-dependent subgenome-partitioning of the allotetraploids. The allotetraploids were meiotically unstable primarily due to homoeologous pairing that varied dramatically among the chromosomes. Nonetheless, the manifestation of organismal k...