Zhu Xiangtao, Zhu Huijun, Ji Wen, Hong Erman, Lu Zeyun, Li Bole, Chen Xia
College of Jiyang, Zhejiang A&F University, Zhuji, China.
Zhejiang Provincial Key Laboratory of Germplasm Innovation and Utilization for Garden Plants, Zhejiang A&F University, Hangzhou, China.
Front Plant Sci. 2022 Nov 3;13:1046881. doi: 10.3389/fpls.2022.1046881. eCollection 2022.
The efficient induction of peony embryogenic callus is of great significance to the improvement and establishment of its regeneration technology system. In this study, the embryos of 'Fengdanbai' at different developmental stages were selected as explants, the effects of different concentrations and types of plant growth regulator combinations on the induction and proliferation of embryonic callus at different developmental stages were investigated, and comparative transcriptome analysis of callus with different differentiation potentials were performed to explore the molecular mechanisms affecting callus differentiation. The results showed that the germination rate of 90d seed embryo was the best, which was 94.17%; the 70d and 80d cotyledon callus induction effect was the best, both reaching 100%, but the 80d callus proliferation rate was higher, the proliferation rate reached 5.31, and the optimal induction medium was MS+0.1 mg·LNAA+0.3 mg·LTDZ+3 mg·L2,4-D, the callus proliferation multiple was 4.77. Based on the comparative transcriptomic analysis, we identified 3470 differentially expressed genes (DEGs) in the callus with high differentiation rate and low differentiation rate, including 1767 up-regulated genes and 1703 down-regulated genes. Pathway enrichment analysis showed that the "Phenylpropanoid biosynthesis" metabolic pathway was significantly enriched, which is associated with promoting further development of callus shoots and roots. This study can provide reference for genetic improvement and the improvement of regeneration technology system of peony.
高效诱导牡丹胚性愈伤组织对其再生技术体系的完善和建立具有重要意义。本研究选取不同发育阶段的‘凤丹白’胚作为外植体，研究不同浓度和类型的植物生长调节剂组合对不同发育阶段胚性愈伤组织诱导和增殖的影响，并对具有不同分化潜力的愈伤组织进行比较转录组分析，以探究影响愈伤组织分化的分子机制。结果表明，90d种子胚的萌发率最佳，为94.17%；70d和80d子叶愈伤组织诱导效果最佳，均达100%，但80d愈伤组织增殖率更高，增殖倍数达5.31，最佳诱导培养基为MS+0.1 mg·L NAA+0.3 mg·L TDZ+3 mg·L 2,4-D，愈伤组织增殖倍数为4.77。基于比较转录组分析，我们在高分化率和低分化率愈伤组织中鉴定出3470个差异表达基因（DEGs），其中上调基因1767个，下调基因1703个。通路富集分析表明，“苯丙烷生物合成”代谢通路显著富集，这与促进愈伤组织芽和根的进一步发育有关。本研究可为牡丹的遗传改良和再生技术体系的完善提供参考。
