Key Laboratory of Herbage and Endemic Crop Biotechnology, Ministry of Education, State Key Laboratory of Reproductive Regulation and Breeding of Grassland Livestock, College of Life Science, Inner Mongolia University, Hohhot, 010021, Inner Mongolia, China.
Biomass and Bioenergy Research Center, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China.
Theor Appl Genet. 2022 Feb;135(2):461-472. doi: 10.1007/s00122-021-03976-y. Epub 2021 Nov 3.
Cytochimera potato plants, which mixed with diploid and tetraploid cells, could cause the highest and significantly increased biomass yield than the polyploid and diploid potato plants. Polyploidization is an important approach in crop breeding for agronomic trait improvement, especially for biomass production. Cytochimera contains two or more mixed cells with different levels of ploidy, which is considered a failure in whole genome duplication. Using colchicine treatment with diploid (Dip) potato (Solanum chacoense) plantlets, this study generated tetraploid (Tet) and cytochimera (Cyt) lines, which, respectively, contained complete and partial cells with genome duplication. Compared to the Dip potato, we observed remarkably enhanced plant growth and biomass yields in Tet and Cyt lines. Notably, the Cyt potato straw, which was generated from incomplete genome doubling, was of significantly higher biomass yield than that of the Tet with a distinctively altered cell wall composition. Meanwhile, we observed that one layer of the tetraploid cells (about 30%) in Cyt plants was sufficient to trigger a gene expression pattern similar to that of Tet, suggesting that the biomass dominance of Cyt may be related to the proportion of different ploidy cells. Further genome-wide analyses of co-expression networks indicated that down-regulation (against Dip) of spliceosomal-related transcripts might lead to differential alternative splicing for specifically improved agronomic traits such as plant growth, biomass yield, and lignocellulose composition in Tet and Cyt plants. In addition, this work examined that the genome of Cyt line was relatively stable after years of asexual reproduction. Hence, this study has demonstrated that incomplete genome doubling is a promising strategy to maximize biomass production in potatoes and beyond.
细胞嵌合体马铃薯植株混合了二倍体和四倍体细胞，其生物量产量比多倍体和二倍体马铃薯植株高且显著增加。多倍化是作物改良农业性状的重要途径，尤其是提高生物量产量。细胞嵌合体包含两个或更多具有不同倍性水平的混合细胞，这被认为是整个基因组复制的失败。本研究使用秋水仙素处理二倍体（Dip）马铃薯（Solanum chacoense）苗，产生了四倍体（Tet）和细胞嵌合体（Cyt）系，它们分别包含完整和部分基因组重复的细胞。与 Dip 马铃薯相比，我们观察到 Tet 和 Cyt 系的植物生长和生物量产量显著增强。值得注意的是，不完全基因组加倍产生的 Cyt 马铃薯秸秆的生物量产量明显高于 Tet，细胞壁组成明显改变。同时，我们观察到 Cyt 植物中约 30%的四层四倍体细胞足以触发与 Tet 相似的基因表达模式，表明 Cyt 的生物量优势可能与不同倍性细胞的比例有关。对共表达网络的全基因组分析表明，剪接体相关转录物的下调（相对于 Dip）可能导致特定的差异剪接，从而改善 Tet 和 Cyt 植物的生长、生物量产量和木质纤维素组成等农业性状。此外，本研究还检测到 Cyt 系的基因组在多年无性繁殖后相对稳定。因此，本研究表明不完全基因组加倍是提高马铃薯及其他作物生物量产量的一种很有前途的策略。
