Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, Singapore 117576, Singapore.
Rice (N Y). 2013 Aug 13;6(1):20. doi: 10.1186/1939-8433-6-20.
Photorespiration, a highly wasteful process of energy dissipation, depresses the productivity of C3 plants such as rice (Oryza sativa) under dry and hot conditions. Thus, it is highly required to understand the cellular physiology and relevant metabolic states under photorespiration using systems approaches, thereby devising strategies for improving rice production.
In silico model-driven gene deletion analysis was performed on photorespiring leaf cells under ambient and stressed environmental conditions using our central metabolic network of rice cells. As a result, we identified a number of essential genes for the cell growth across various functional pathways such as photorespiratory cycle, Calvin cycle, GS-GOGAT cycle and sucrose metabolism as well as certain inter-compartmental transporters, which are mostly in good agreement with previous experiments. Synthetic lethal (SL) screening was also performed to identify the pair of non-essential genes whose simultaneous deletion become lethal, revealing the existence of more than 220 pairs of SLs on rice central metabolism.
The gene deletion and synthetic lethal analyses highlighted the rigid nature of rice photosynthetic pathways and characterized functional interactions between central metabolic genes, respectively. The biological roles of such reported essential genes should be further explored to better understand the rice photorespiration in future.
在干旱和炎热的条件下，光合作用会消耗大量能量，从而抑制 C3 植物（如水稻）的生产力。因此，需要采用系统方法来理解光合作用下的细胞生理学和相关代谢状态，从而制定提高水稻产量的策略。
利用我们的水稻细胞中心代谢网络，对环境条件下和应激环境条件下的光合作用叶片细胞进行了基于计算模型的基因缺失分析。结果，我们确定了许多对细胞生长至关重要的基因，这些基因涉及光合作用循环、卡尔文循环、GS-GOGAT 循环和蔗糖代谢等各种功能途径，以及一些跨区室转运蛋白，这与之前的实验结果大多吻合。还进行了合成致死（SL）筛选，以鉴定同时缺失会导致致死的非必需基因对，揭示了水稻中心代谢中存在 220 多对 SL。
基因缺失和合成致死分析分别强调了水稻光合作用途径的刚性性质和中心代谢基因之间的功能相互作用。应该进一步探索这些报道的必需基因的生物学作用，以便将来更好地理解水稻的光合作用。
