Biodiversity and network complexity of rhizosphere soil microbiomes regulate the differentiation of Capsicum growth strategies

Plant growth strategies represent a gradient from slow to fast economic strategies. Rhizosphere microbiomes have a continual and profound impact on plant growth. However, our understanding of differences in plant economic spectrum among various crop varieties and their associations with rhizosphere microbiome remains limited.

Here, pepper (Capsicum spp.) was employed as a model plant to examine the differentiation of 73 varieties in plant economic strategies. Meanwhile, this study explored the associations of economic strategy differentiation with rhizosphere microbiomes.

The 73 varieties displayed significant differentiation in both above- and below-ground growth traits, enabling their growth classification into fast economic strategy (FES), medium economic strategy (MES), and slow economic strategy (SES). A significantly consistent distribution was observed among plant functional traits and rhizosphere microbial communities (bacteria and protists) of SES varieties, which was not discovered in FES varieties. Compared with FES varieties, the SES varieties exhibited a lower microbial diversity and community complexity. Pepper varieties with SES were more strongly correlated with their rhizosphere microbiomes compared to FES varieties. Rhizosphere microbial and community complexity indirectly regulated above-ground growth of SES varieties by affecting the root growth and nutrient uptake.

Overall, these findings enhance our understanding of the connections between plant economic strategies and rhizosphere microbiomes, offering valuable insights into selection and popularization of exceptional Capsicum varieties.