Tang Xiumei, He Yonglin, Zhang Zheng, Wu Haining, He Liangqiong, Jiang Jing, Meng Weiwei, Huang Zhipeng, Xiong Faqian, Liu Jing, Zhong Ruichun, Han Zhuqiang, Wan Shubo, Tang Ronghua
Cash Crops Research Institute, Guangxi Academy of Agricultural Sciences, Nanning, China.
Key Lab of Crop Genetic Improvement and Ecological Physiology of Shandong, Shandong Academy of Agricultural Sciences, Jinan, China.
Front Plant Sci. 2022 Dec 2;13:1018727. doi: 10.3389/fpls.2022.1018727. eCollection 2022.
Intercropping systems have been studied as a sustainable agricultural planting pattern to increase soil quality and crop yields. However, the relationships between metabolites and soil physicochemical properties remain poorly understood under sugarcane/peanut intercropping system. Thus, we determined the rhizosphere soil physicochemical properties, and analyzed rhizosphere soil metabolites and root metabolites by metabolomics method under monoculture and intercropping patterns of sugarcane and peanut. The results showed that pH, the contents of total phosphorus (P), total potassium (K), available nitrogen (N), available phosphorus (P), and available potassium (K) were higher in rhizosphere soil of intercropping peanut than monoculture peanut, and the content of total P was higher in rhizosphere soil of intercropping sugarcane than monoculture sugarcane. Sugarcane/peanut intercropping also significantly increased the activities of acid phosphatase and urease in rhizosphere soil. The metabolomics results showed that 32 metabolites, mainly organic acids and their derivatives (25.00%), nucleotides and their metabolites (18.75%), were detected in root and rhizosphere soil samples. In the MP-S (rhizosphere soil of monoculture peanut) vs. IP-S (rhizosphere soil of intercropping peanut) comparison, 47 differential metabolites (42 upregulated) were screened, including glycerolipids (19.15%), organic acids and their derivatives (17.89%), and amino acids and their metabolites (12.77%). In the MS-S (rhizosphere soil of monoculture sugarcane) vs. IS-S (rhizosphere soil of intercropping sugarcane) comparison, 51 differential metabolites (26 upregulated) were screened, including heterocyclic compounds (15.69%), glycerolipids (11.76%), and organic acids and their derivatives (9.80%). The metabolite species from MP-S, MS-S, IP-S, and IS-S were similar, but some metabolite contents were significantly different, such as adenine, adenosine, maltotriose, thermozeaxanthin-13 and PE-NMe (20:0/24:0). Adenine and adenosine were detected in root and rhizosphere soils, and their levels were increased in the intercropping treatment, which were mainly related to enhanced purine metabolism in root and rhizosphere soils under the sugarcane/peanut intercropping system. Importantly, adenine and adenosine were significantly positively correlated with total P and total K contents, acid phosphatase and urease activities, and pH. This study clarified that the sugarcane/peanut intercropping system could improve soil nutrients and enzymes and was related to purine metabolism.
间作系统作为一种可持续的农业种植模式，已被用于提高土壤质量和作物产量。然而，在甘蔗/花生间作系统下，代谢产物与土壤理化性质之间的关系仍不清楚。因此，我们测定了单作和间作模式下甘蔗和花生根际土壤的理化性质，并采用代谢组学方法分析了根际土壤代谢产物和根系代谢产物。结果表明，间作花生根际土壤的pH值、总磷（P）、总钾（K）、碱解氮（N）、有效磷（P）和有效钾（K）含量均高于单作花生，间作甘蔗根际土壤的总磷含量高于单作甘蔗。甘蔗/花生间作还显著提高了根际土壤酸性磷酸酶和脲酶的活性。代谢组学结果表明，在根和根际土壤样品中检测到32种代谢产物，主要是有机酸及其衍生物（25.00%）、核苷酸及其代谢产物（18.75%）。在单作花生根际土壤（MP-S）与间作花生根际土壤（IP-S）的比较中，筛选出47种差异代谢产物（42种上调），包括甘油脂（19.15%）、有机酸及其衍生物（17.89%）和氨基酸及其代谢产物（12.77%）。在单作甘蔗根际土壤（MS-S）与间作甘蔗根际土壤（IS-S）的比较中，筛选出51种差异代谢产物（26种上调），包括杂环化合物（15.69%）、甘油脂（11.76%）和有机酸及其衍生物（9.80%）。MP-S、MS-S、IP-S和IS-S的代谢产物种类相似，但一些代谢产物含量存在显著差异，如腺嘌呤、腺苷、麦芽三糖、热玉米黄质-13和PE-NMe（20:0/24:0）。在根和根际土壤中均检测到腺嘌呤和腺苷，间作处理下其含量增加，这主要与甘蔗/花生间作系统下根和根际土壤中嘌呤代谢增强有关。重要的是，腺嘌呤和腺苷与总磷、总钾含量、酸性磷酸酶和脲酶活性以及pH值呈显著正相关。本研究阐明了甘蔗/花生间作系统可以改善土壤养分和酶活性，且与嘌呤代谢有关。
