解密土壤植物的根系分泌物组成被认为是更好地了解影响植物生长性能的植物-土壤-微生物相互作用的关键步骤。在这项研究中,玉米的两种基因型(WT,rth3)在两种基质(沙子,壤土)定制,插入到字段图中的穿孔列。使用土壤-水培-杂种渗出取样方法,在不同的植物发育阶段(BBCH14、19、59、83)收集根系分泌物。渗出物通过基于LC-MS的非靶向代谢组学进行表征,以及通过针对总溶解有机碳的分光光度测定法,可溶性碳水化合物,蛋白质,氨基酸,和酚类物质.结果表明,植物发育阶段是渗出化合物组成和数量的主要驱动因素。随着时间的推移,每株植物的碳(C)渗出随着生物量产量的增加而增加,而每cm²根表面积h-1的C渗出率随植物成熟而降低。此外,养分迁移率较低的底物的渗出率较高(即,壤土)。令人惊讶的是,我们观察到根无毛rth3的渗出率高于根毛形成的WT同胞,尽管渗出物代谢物组成保持相似。我们的结果强调了植物发育阶段对植物-土壤-微生物相互作用的影响。
Deciphering root exudate composition of soil-grown plants is considered a crucial step to better understand plant-soil-microbe interactions affecting plant growth performance. In this study, two genotypes of Zea mays L. (WT, rth3) differing in root hair elongation were grown in the field in two substrates (sand, loam) in custom-made, perforated columns inserted into the field plots. Root exudates were collected at different plant developmental stages (BBCH 14, 19, 59, 83) using a soil-hydroponic-hybrid exudation sampling approach. Exudates were characterized by LC-MS based non-targeted metabolomics, as well as by photometric assays targeting total dissolved organic carbon, soluble carbohydrates, proteins, amino acids, and phenolics. Results showed that plant developmental stage was the main driver shaping both the composition and quantity of exuded compounds. Carbon (C) exudation per plant increased with increasing biomass production over time, while C exudation rate per cm² root surface area h-1 decreased with plant maturity. Furthermore, exudation rates were higher in the substrate with lower nutrient mobility (i.e., loam). Surprisingly, we observed higher exudation rates in the root hairless rth3 mutant compared to the root hair-forming WT sibling, though exudate metabolite composition remained similar. Our results highlight the impact of plant developmental stage on the plant-soil-microbe interplay.