Gu Xiaoyan, Fang Zhou, Tan Jiarui, Chen Sen, Peng Jiahui, Feng Wei, Huang Yiqin, Cao Ying, Hu Shanglian
Lab of Plant Cell Engineering, Southwest University of Science and Technology, Mianyang, 621010, Sichuan, China.
Engineering Research Center for Biomass Resource Utilizaiton and Modification of Sichuan Province, Mianyang, 621010, Sichuan, China.
BMC Plant Biol. 2025 Sep 1;25(1):1170. doi: 10.1186/s12870-025-07267-2.
Bamboo usually undergoes a prolonged vegetative growth period for several decades. Additionally, not all bamboo species produce seeds, and the regulatory mechanisms governing embryogenic callus formation remain unclear, which constrains molecular breeding progress in bamboo. Here, we used buds of Bambusa changningensis Yi et B. X. Li as explants for callus induction. The results revealed that bamboo embryogenic callus (EC) on media added coconut powder, 2,4-D and proline increased faster than that on other media. The content of EC increased with the increase of 2,4-D concentration on different media. The concentrations of auxin and gibberellin (GA) in non-embryogenic callus (NE) were significantly higher than those in EC. Furthermore, RNA-seq analysis revealed that 795 DEGs were mainly enriched in pathways of starch synthase and amyloplast metabolism. Gene set analysis revealed that genes associated with amylopectin synthesis and metabolism pathways were upregulated in EC, and several starch synthesis-related genes were significantly enriched in EC. We then observed that EC exhibited more clearly amyloplast, higher starch content, and three starch metabolism related genes (SS1, SBE1, STP-1) showed higher expression levels compared to NE. Collectively, these results identified that the transition from NE to EC was associated with amyloplast synthesis and metabolism, and it providing new insights into the establishment of callus regeneration and genetic transformation systems in bamboo.
竹子通常会经历长达数十年的营养生长阶段。此外，并非所有竹种都会产生种子，而且调控胚性愈伤组织形成的机制仍不清楚，这限制了竹子分子育种的进展。在此，我们以长宁竹（Bambusa changningensis Yi et B. X. Li）的芽为外植体进行愈伤组织诱导。结果表明，添加椰子粉、2,4-D和脯氨酸的培养基上的竹子胚性愈伤组织（EC）比其他培养基上的生长更快。在不同培养基上，EC的含量随2,4-D浓度的增加而增加。非胚性愈伤组织（NE）中的生长素和赤霉素（GA）浓度显著高于EC中的。此外，RNA测序分析表明，795个差异表达基因主要富集在淀粉合酶和造粉体代谢途径中。基因集分析表明，与支链淀粉合成和代谢途径相关的基因在EC中上调，并且几个与淀粉合成相关的基因在EC中显著富集。然后我们观察到，与NE相比，EC表现出更明显的造粉体、更高的淀粉含量，并且三个与淀粉代谢相关的基因（SS1、SBE1、STP-1）显示出更高的表达水平。总体而言，这些结果表明从NE到EC的转变与造粉体的合成和代谢有关，为竹子愈伤组织再生和遗传转化系统的建立提供了新的见解。
