Liu Xin, Gao Yingbo, Tang Siyuan, Ben Linli, Zhang Xiaoxiang, Dong Guichun, Zhou Juan, Lin Lingshang, Yang Zefeng, Zhou Yong, Huang Jianye, Yao Youli
Jiangsu Key Laboratory of Crop Genetics and Physiology, Jiangsu Key Laboratory of Crop Cultivation and Physiology, Agricultural College of Yangzhou University, Yangzhou, 225009, Jiangsu, China.
Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops, Yangzhou University, Yangzhou, 225009, Jiangsu, China.
Rice (N Y). 2025 Apr 17;18(1):28. doi: 10.1186/s12284-025-00779-3.
Fructose-1,6-bisphosphate aldolase (FBA) stands as a pivotal enzyme involved within the Calvin cycle and glycolytic pathways in bacteria and higher plants, but the specific function of OsFBA in rice is still unclear. Here, we identified a chloroplast and mitochondria dual-localized FBA protein, OsFBA1, in rice. Experimental evidence showed that the functionally deficient osfba1 mutants featured a notable decline in chlorophyll content, photosynthetic rate, and severe growth impediment by the three-leaf stage, leading to eventual plant demise. Up-regulation of photosynthetic-pathway genes in the osfba1 mutants indicated the essential role of OsFBA1 in chloroplast development and suggested a compensatory mechanism of other genes in the process. Furthermore, the absence of OsFBA1 impaired the carbon assimilation in young rice seedlings, and supplying exogenous glucose could partially sustain the survival of osfba1 mutant for a few more days. Pathway-specific metabolomics analysis revealed a systemic change of metabolites in the glycolytic pathway, and consequential carbohydrates accumulation due to OsFBA1 disruption. Transcriptomics profiling corroborated the expression changes of photosynthesis, and carbon metabolism pathway genes. We further demonstrated that OsFBA1 serves as the primary FBA enzyme governing energy generation, photosynthesis and carbon metabolism. These results prove that OsFBA1 is an essential core gene in supporting the life cycle of rice, its expression has to be tightly regulated.
果糖-1,6-二磷酸醛缩酶（FBA）是细菌和高等植物卡尔文循环及糖酵解途径中的关键酶，但OsFBA在水稻中的具体功能仍不清楚。在此，我们在水稻中鉴定出一种定位于叶绿体和线粒体的双定位FBA蛋白OsFBA1。实验证据表明，功能缺陷型osfba1突变体在三叶期时叶绿素含量、光合速率显著下降，生长严重受阻，最终导致植株死亡。osfba1突变体中光合途径基因的上调表明OsFBA1在叶绿体发育中起关键作用，并暗示了该过程中其他基因的补偿机制。此外，OsFBA1的缺失损害了水稻幼苗的碳同化，供应外源葡萄糖可使osfba1突变体存活多几天。途径特异性代谢组学分析揭示了糖酵解途径中代谢物的系统性变化，以及由于OsFBA1破坏导致的碳水化合物积累。转录组分析证实了光合作用和碳代谢途径基因的表达变化。我们进一步证明，OsFBA1是控制能量产生、光合作用和碳代谢的主要FBA酶。这些结果证明，OsFBA1是支持水稻生命周期的必需核心基因，其表达必须受到严格调控。
