College of Life Science and Technology, Inner Mongolia Normal University, Huhehaote, China; College of Landscape Architecture and Art, Henan Agricultural University, Zhengzhou, China.
College of Forestry, Henan Agricultural University, Zhengzhou, China.
Plant Physiol Biochem. 2023 Sep;202:107945. doi: 10.1016/j.plaphy.2023.107945. Epub 2023 Aug 6.
Whole genome doubling (WGD) plays a critical role in plant evolution, yet the mechanisms underlying the maintenance of overall equilibrium following an artificial doubling event, as well as its impact on phenotype and adaptability, remain unclear. By comparing the gene expression of naturally occurring weeping forsythia diploids and colchicine-induced autotetraploids under normal growth conditions and cold stress, we identified gene expression dosage responses resulting from ploidy change. Only a small proportion of effectively expressed genes showed dosage effect, and most genes did not exhibit significant expression differences. However, the genes that showed expression dosage effect were largely random. The autotetraploids had slower overall growth rates, possibly resulting from negative gene dosage effects on zeatin synthesis and multiple metabolic delays caused by other negative dosage genes. Our comparative analysis of cold response genes in diploids and autotetraploids revealed that genes related to "response to abscisic acid" and "cold acclimation" were key factors contributing to greater cold tolerance in the autotetraploids. In particular, gene expression related to "cold acclimation" might mitigate the effects of cold stress. Taken together, our findings suggested that overall gene expression equilibrium following WGD of weeping forsythia autotetraploids was achieved through the inactivation of the majority of duplicated genes. Our research provides new insights into the mechanisms regulating expression dosage balance following polyploidization events.
全基因组加倍 (WGD) 在植物进化中起着至关重要的作用，但人工加倍事件后维持整体平衡的机制及其对表型和适应性的影响仍不清楚。通过比较自然发生的垂丝海棠二倍体和秋水仙素诱导的同源四倍体在正常生长条件和冷胁迫下的基因表达，我们鉴定了由倍性变化引起的基因表达剂量反应。只有一小部分有效表达的基因表现出剂量效应，而大多数基因没有表现出显著的表达差异。然而，表现出表达剂量效应的基因很大程度上是随机的。同源四倍体的整体生长速度较慢，可能是由于 zeatin 合成的负基因剂量效应以及其他负剂量基因引起的多种代谢延迟所致。我们对二倍体和同源四倍体中冷响应基因的比较分析表明，与“对脱落酸的响应”和“冷适应”相关的基因是同源四倍体具有更高耐寒性的关键因素。特别是，与“冷适应”相关的基因表达可能减轻了冷胁迫的影响。总之，我们的研究结果表明，垂丝海棠同源四倍体 WGD 后整体基因表达平衡是通过大多数重复基因的失活来实现的。我们的研究为调控多倍化事件后表达剂量平衡的机制提供了新的见解。
