SummaryRain-fed plants are subjected to cycles of drought and re-watering. Thus, efficient recovery from drought may be among the key determinants in the success of these plants. We performed a fine-scale time course of bulk RNA sequencing and revealed that transcriptional drought recovery is an active and rapid process involving activating over 3000 recovery-specific genes. We found that upon rehydration, there is a rapid microbial-autonomic induction of the immune system. We termed this response drought recovery-induced immunity (DRII). To reveal the immediate cell-type-specific responses that occur upon recovery we performed a single-nucleus transcriptome analysis of plants recovering from drought and profiled >126,000 transcriptomes. We found that the DRII response manifests in sub-populations of epidermal, trichome, and mesophyll cells immediately following rehydration. Finally, inoculation assays withPseudomonas syringaepv.tomatoDC3000 demonstrated that DRII increases plant resistance against pathogens. Since rehydration increases microbial proliferation and thus, the risk for infection, the DRII response may be crucial for plant survival in water-fluctuating environments.
