Li Yihan, Li Shuangyu, Hua Xiuting, Xu Yi, Chen Shuqi, Yu Zehuai, Zhuang Gui, Lan Yuhong, Yao Wei, Chen Baoshan, Zhang Muqing, Zhang Jisen
State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Guangxi Key Laboratory of Sugarcane Biology, College of Agriculture, Guangxi University, Nanning, 530004, China.
Fujian Provincial Key Laboratory of Haixia Applied Plant Systems Biology, Center for Genomics and Biotechnology, Fujian Agriculture and Forestry University, Fuzhou, 350002, China.
BMC Genomics. 2025 Jan 10;26(1):28. doi: 10.1186/s12864-025-11210-y.
Sugarcane is a crucial crop for both sugar and bioethanol production. The nobilization breeding and utilization of wild germplasm have significantly enhanced its productivity. However, the pollen sterility in Saccharum officinarum restricts its role to being a female parent in crosses with Saccharum spontaneum during nobilization breeding, resulting in a narrow genetic basis for modern sugarcane cultivars. Mitochondria, often referred to as the intracellular "energy factories", provide energy for plant life activities, and are also implicated in cytoplasmic male sterility (CMS).
We performed mitochondrial genome assembly and structural analysis of two Saccharum founding species. We discovered that the proportions of repeat sequences are the primary factor contributing to the variations in mitochondrial genome structure and size between the two Saccharum species. Heterologous expression of the mitochondrial chimeric gene ORF113, which is highly expressed in male-sterile S. officinarum flowers, significantly inhibits growth and ATP synthesis in yeast cells, making it a key candidate CMS-related gene in sugarcane. Furthermore, we developed two co-dominant simple sequence repeat (SSR) markers based on the mitochondrial genome, which can effectively distinguish the cytoplasmic types of the two Saccharum species.
In this study, we identified structural variants and developed SSR molecular markers in the mitochondrial genomes of both S. officinarum and S. spontaneum. We also identified a novel mitochondrial chimeric ORF as a key candidate CMS-related gene. These findings offer valuable insights into variety identification, genetic resource development, and cross-breeding strategies in sugarcane.
甘蔗是制糖和生物乙醇生产的关键作物。野生种质的驯化育种和利用显著提高了其生产力。然而，甘蔗属热带种的花粉不育限制了其在驯化育种中作为母本与甘蔗属野生种杂交的作用，导致现代甘蔗品种的遗传基础狭窄。线粒体常被称为细胞内的“能量工厂”，为植物生命活动提供能量，也与细胞质雄性不育（CMS）有关。
我们对甘蔗两个原始物种进行了线粒体基因组组装和结构分析。我们发现重复序列的比例是导致这两个甘蔗物种线粒体基因组结构和大小差异的主要因素。线粒体嵌合基因ORF113在雄性不育的甘蔗属热带种花中高度表达，其异源表达显著抑制酵母细胞的生长和ATP合成，使其成为甘蔗中一个关键的候选CMS相关基因。此外，我们基于线粒体基因组开发了两个共显性简单序列重复（SSR）标记，可有效区分这两个甘蔗物种的细胞质类型。
在本研究中，我们在甘蔗属热带种和甘蔗属野生种的线粒体基因组中鉴定了结构变异并开发了SSR分子标记。我们还鉴定了一个新的线粒体嵌合ORF作为关键的候选CMS相关基因。这些发现为甘蔗的品种鉴定、遗传资源开发和杂交育种策略提供了有价值的见解。
