Table_1_Merging the occurrence possibility into gene co-expression network deciphers the importance of exogenous 2-oxoglutarate in improving the growth of rice seedlings under thiocyanate stress.doc

Thiocyanate (SCN−) can find its way into cultivated fields, which might hamper the harmony in carbon and nitrogen metabolism (CNM) of plants, ebbing their quality and productivity. In the current study, we investigated the role of the exogenous application of 2-oxoglutarate (2-OG) in maintaining homeostasis of CNM in rice seedlings under SCN− stress. Results showed that SCN− exposure significantly repressed the gene expression and activities of CNM-related enzymes (e.g., phosphoenolpyruvate carboxylase, NADP-dependent isocitrate dehydrogenases, and isocitrate dehydrogenases) in rice seedlings, thereby reducing their relative growth rate (RGR). Exogenous application of 2-OG effectively mitigated the toxic effects of SCN− on rice seedlings, judged by the aforementioned parameters. The co-expression network analysis showed that genes activated in CNM pathways were categorized into four modules (Modules 1–4). In order to identify the key module activated in CNM in rice seedlings exposed to SCN−, the results from real-time quantitative PCR (RT-qPCR) tests were used to calculate the possibility of the occurrence of genes grouped in four different modules. Notably, Module 3 showed the highest occurrence probability, which is mainly related to N metabolism and 2-OG synthesis. We can conclude that exogenous application of 2-OG can modify the imbalance of CNM caused by SCN− exposure through regulating N metabolism and 2-OG synthesis in rice seedlings.

硫氰酸根（SCN−）可渗透至耕作田地，进而干扰植物碳氮代谢（CNM）的和谐平衡，导致其品质与生产力下降。在本研究中，我们探讨了外源施用2-氧代谷氨酸（2-OG）在维持水稻幼苗在SCN−胁迫下CNM稳态中的作用。研究结果表明，SCN−的暴露显著抑制了水稻幼苗中与CNM相关的酶（例如，磷酸烯醇式丙酮酸羧化酶、NADP依赖性异柠檬酸脱氢酶和异柠檬酸脱氢酶）的基因表达和活性，从而降低了其相对生长速率（RGR）。外源施用2-OG有效地缓解了SCN−对水稻幼苗的毒性影响，上述参数可作为判断依据。共表达网络分析显示，参与CNM途径的基因可分为四个模块（模块1-4）。为了识别水稻幼苗在SCN−暴露下CNM中的关键激活模块，我们利用实时定量PCR（RT-qPCR）测试结果计算了四个不同模块中基因组分的出现可能性。值得注意的是，模块3表现出最高的出现概率，其主要与氮代谢和2-OG合成相关。据此，我们可以得出结论，外源施用2-OG可通过调节水稻幼苗中的氮代谢和2-OG合成来改变SCN−暴露引起的CNM失衡。