Biophysics Group, Biomedical Center, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China.
University of Chinese Academy of Sciences, Beijing 100049, China.
Int J Mol Sci. 2023 May 26;24(11):9287. doi: 10.3390/ijms24119287.
Rodin (TKS) has great potential as an alternative natural-rubber (NR)-producing crop. The germplasm innovation of TKS still faces great challenges due to its self-incompatibility. Carbon-ion beam (CIB) irradiation is a powerful and non-species-specific physical method for mutation creation. Thus far, the CIB has not been utilized in TKS. To better inform future mutation breeding for TKS by the CIB and provide a basis for dose-selection, adventitious buds, which not only can avoid high levels of heterozygosity, but also further improve breeding efficiency, were irradiated here, and the dynamic changes of the growth and physiologic parameters, as well as gene expression pattern were profiled, comprehensively. The results showed that the CIB (5-40 Gy) caused significant biological effects on TKS, exhibiting inhibitory effects on the fresh weight and the number of regenerated buds and roots. Then,15 Gy was chosen for further study after comprehensive consideration. CIB-15 Gy resulted in significant oxidative damages (hydroxyl radical (OH) generation activity, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity and malondialdehyde (MDA) content) and activated the antioxidant system (superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), and ascorbate peroxidase (APX)) of TKS. Based on RNA-seq analysis, the number of differentially expressed genes (DEGs) peaked at 2 h after CIB irradiation. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis revealed that DNA-replication-/repair- (mainly up-regulated), cell-death- (mainly up-regulated), plant-hormone- (auxin and cytokinin, which are related to plant morphogenesis, were mainly down-regulated), and photosynthesis- (mainly down-regulated) related pathways were involved in the response to the CIB. Furthermore, CIB irradiation can also up-regulate the genes involved in NR metabolism, which provides an alternative strategy to elevate the NR production in TKS in the future. These findings are helpful to understand the radiation response mechanism and further guide the future mutation breeding for TKS by the CIB.
杜仲（TKS）作为一种具有巨大潜力的天然橡胶（NR）替代作物。由于其自交不亲和性，TKS 的种质创新仍然面临巨大挑战。碳离子束（CIB）辐照是一种强大的、非物种特异性的诱变创造物理方法。迄今为止，CIB 尚未在 TKS 中得到应用。为了更好地为未来通过 CIB 对 TKS 进行诱变育种提供信息，并为剂量选择提供依据，本研究利用 CIB 辐照不定芽，全面分析其生长和生理参数以及基因表达模式的动态变化。结果表明，CIB（5-40 Gy）对 TKS 产生了显著的生物学效应，表现为对鲜重和再生芽和根的数量的抑制作用。综合考虑后，选择 15 Gy 进行进一步研究。CIB-15 Gy 导致 TKS 产生显著的氧化损伤（羟自由基（OH）生成活性、1,1-二苯基-2-苦基肼（DPPH）自由基清除活性和丙二醛（MDA）含量），并激活 TKS 的抗氧化系统（超氧化物歧化酶（SOD）、过氧化氢酶（CAT）、过氧化物酶（POD）和抗坏血酸过氧化物酶（APX））。基于 RNA-seq 分析，CIB 辐照后 2 h 差异表达基因（DEGs）数量达到峰值。基因本体论（GO）和京都基因与基因组百科全书（KEGG）分析表明，与 DNA 复制/修复（主要上调）、细胞死亡（主要上调）、植物激素（与植物形态发生有关的生长素和细胞分裂素，主要下调）和光合作用（主要下调）相关的途径参与了对 CIB 的反应。此外，CIB 辐照还可以上调参与 NR 代谢的基因，这为未来提高 TKS 中的 NR 产量提供了一种替代策略。这些发现有助于了解辐射响应机制，并进一步指导未来通过 CIB 对 TKS 进行诱变育种。
