Role of core and unique communities in root bacterial community of sorghum cultivar Hongyingzi

The role of core communities (CC) and unique communities (UC) in root bacterial community of sorghum cultivar Hongyingzi in shaping the diversity of the entire community (EC) was investigated, and the impact on the nutrients of soil in root system was explored based on 15 soil nutrient indices. The results revealed that CC and UC were dominated by abundant and rare microbiota, respectively. The Shannon and mean pairwise phylogenetic distance (MPD) indexes of UC were significantly higher than those of CC (P<0.05), and MPD index of UC was significantly higher than that of EC (P<0.05), indicating that UC played a critical role in maintaining α-diversity levels of EC. Both CC and UC were highly significantly correlated with EC succession (P<0.01), while there was no significant correlation between CC and UC (P>0.05), indicating that EC succession was simultaneously influenced by CC and UC, but the succession patterns between CC and UC were relatively independent. The contributions of CC and UC to EC succession were 49.1% and 20.0%, respectively, indicating that CC was the primary driving force behind EC succession. A total of 8 dominant bacterial phyla were identified in EC, represented by Proteobacteria (59.4%) and Actinobacteria (14.2%). Furthermore, as the microbiota migrated towards root tissues, their effects on changes in nutrients of soil in root system, particularly those related to nitrogen, phosphorus, and potassium cycling, became more pronounced. Regarding the rhizosphere and rhizoplane, CC was the major community influencing soil nutrients changes in EC, with the distribution of microbiota significantly affecting organic matter occurring mainly in the rhizosphere.