National Key Laboratory for Germplasm Innovation and Utilization of Horticultural Crops, College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan 430070, China.
Int J Mol Sci. 2023 Sep 23;24(19):14486. doi: 10.3390/ijms241914486.
Transcription and alternative splicing (AS) are now appreciated in plants, but few studies have examined the effects of changing ploidy on transcription and AS. In this study, we showed that artificially autododecaploid plants of London plane ( × (Aiton) Willd) had few flowers relative to their hexaploid progenitors. Transcriptome analysis based on full-length Oxford Nanopore Technologies (ONTs) and next-generation sequencing (NGS) revealed that the increased ploidy level in × led to more transcribed isoforms, accompanied by an increase in the number of isoforms per gene. The functional enrichment of genes indicated that novel genes transcribed specifically in the dodecaploids may have been highly correlated with the ability to maintain genome stability. The dodecaploids showed a higher number of genes with upregulated differentially expressed genes (DEGs) compared with the hexaploid counterpart. The genome duplication of × resulted mainly in the DEGs involved in basic biological pathways. It was noted that there was a greater abundance of alternative splicing (AS) events and AS genes in the dodecaploids compared with the hexaploids in × . In addition, a significant difference between the structure and expression of AS events between the hexaploids and dodecaploids of was found. Of note, some DEGs and differentially spliced genes (DSGs) related to floral transition and flower development were consistent with the few flower traits in the dodecaploids of × . Collectively, our findings explored the difference in transcription and AS regulation between the hexaploids and dodecaploids of × and gained new insight into the molecular mechanisms underlying the few-flower phenotype of × . These results contribute to uncovering the regulatory role of transcription and AS in polyploids and breeding few-flower germplasms.
转录和可变剪接（AS）在植物中现已得到广泛研究，但鲜有研究探讨倍性变化对转录和 AS 的影响。本研究表明，与六倍体亲本相比，人工自诱导的伦敦悬铃木（× (Aiton) Willd）同源多倍体植物的花较少。基于全长牛津纳米孔技术（ONTs）和下一代测序（NGS）的转录组分析表明，× 中较高的倍性水平导致更多转录的异构体，同时每个基因的异构体数量增加。基因的功能富集表明，在十二倍体中特异性转录的新基因可能与维持基因组稳定性的能力高度相关。与六倍体相比，十二倍体中上调的差异表达基因（DEGs）的数量更多。× 的基因组加倍主要导致参与基本生物学途径的 DEGs。值得注意的是，与六倍体相比，十二倍体中存在更多的可变剪接（AS）事件和 AS 基因。此外，在 × 的六倍体和十二倍体之间发现了 AS 事件结构和表达之间的显著差异。值得注意的是，一些与花发育和花发育相关的 DEG 和差异剪接基因（DSGs）与 × 的十二倍体花少的性状一致。总之，我们的研究结果探讨了 × 的六倍体和十二倍体之间转录和 AS 调控的差异，并深入了解了 × 花少表型的分子机制。这些结果有助于揭示转录和 AS 在多倍体中的调控作用，并为培育花少的种质资源提供了新的思路。
