College of Pharmaceutical Sciences, Soochow University, Suzhou, 215123, China.
College of Pharmaceutical Sciences, Soochow University, Suzhou, 215123, China.
Plant Physiol Biochem. 2018 Sep;130:112-126. doi: 10.1016/j.plaphy.2018.06.018. Epub 2018 Jun 18.
To investigate on the effects of autopolyploidization on growth and artemisinin biosynthesis in Artemisia annua, we performed a comprehensive transcriptomic characterization of diploid and induced autotetraploid A. annua. The polyploidization treatment not only enhanced photosynthetic capacity and endogenous contents of indole-3-acetic acid (IAA), abscisic acid (ABA) and jasmonic acid (JA), oxidative stress, but increased the average level of artemisinin in tetraploids from 42.0 to 63.6%. The obvious phenotypic alterations in tetraploids were observed including shorter stems, larger size of stomata and glandular secretory trichomes (GSTs), larger leaves, more branches and roots. A total of 8763 (8.85%) differentially expressed genes (DEGs) were identified in autotetraploids and mainly involved in carbohydrate metabolic processes, cell wall organization and defense responses. Both the up-regulated expression of DNA methylation unigenes and enhanced level of DNA methylation in autotetraploids indicated a possible role of DNA methylation on transcriptomic remodeling and phenotypic alteration. The up-regulated genes were enriched in response to extracellular protein biosynthesis, photosynthesis and hormone stimulus for cell enlargement and phenotypic alteration. The genomic shock induced by chromosome duplication stimulated the expression of transcripts related to oxidative stress, biosynthesis and signal transduction of ABA and JA, and key enzymes in artemisinin biosynthetic pathway, leading to the increased accumulation of artemisinin. This is the first transcriptomic research that identifies DEGs involved in the polyploidization of A. annua. The results provide novel information for understanding the complexity of polyploidization and for further identification of the factors and genes involve in artemisinin biosynthesis.
为了研究同源多倍化对黄花蒿生长和青蒿素生物合成的影响，我们对二倍体和诱导的同源四倍体黄花蒿进行了全面的转录组特征分析。多倍化处理不仅增强了光合能力和内源吲哚-3-乙酸（IAA）、脱落酸（ABA）和茉莉酸（JA）的含量、氧化应激，还将四倍体青蒿素的平均水平从 42.0%提高到 63.6%。在四倍体中观察到明显的表型变化，包括茎变短、气孔和腺毛分泌毛（GSTs）变大、叶变大、分枝和根增多。在同源四倍体中鉴定出 8763 个（8.85%）差异表达基因（DEGs），主要涉及碳水化合物代谢过程、细胞壁组织和防御反应。同源四倍体中 DNA 甲基化基因的上调表达和 DNA 甲基化水平的增强表明 DNA 甲基化可能在转录组重塑和表型改变中发挥作用。上调的基因富集在细胞外蛋白质生物合成、光合作用和激素刺激细胞增大和表型改变的反应中。染色体加倍引起的基因组冲击刺激了与氧化应激、ABA 和 JA 生物合成和信号转导以及青蒿素生物合成途径关键酶相关的转录物的表达，导致青蒿素的积累增加。这是首次对黄花蒿多倍体化相关 DEGs 进行的转录组研究。研究结果为理解多倍体化的复杂性以及进一步鉴定参与青蒿素生物合成的因素和基因提供了新的信息。
