In our study on maize root exudates (Henry, C. et al, 2025, in preparation), we developed a non-invasive rhizosampling method that enables the repeated capture of metabolites and microbiomes from soil-grown maize over time. Using LC-MS metabolomics and 16S amplicon sequencing, we found that developmental stage was the dominant factor structuring both exudate and microbial profiles. Genotype played a larger role in shaping metabolite composition, for example, B73 exuded higher levels of benzoxazinoids such as DIMBOA and benzoxazolone, while Mo17 and W605S displayed similar profiles reflecting their closer genetic relationship. In contrast, heat stress drove the most pronounced changes in the microbiome, including shifts in the relative abundance of Massilia and Azospirillum within the Pseudomonadota phylum, and a notable decline in Luteolibacter under heat. We also observed that heat stress disproportionately induced sulfur-containing metabolites, a class of compounds linked to oxidative stress mitigation. Together, these findings underscore how genotype, abiotic stress, and developmental timing interact to shape below-ground communication, and they establish a scalable platform for linking root exudation to plant performance under climate stress.