Comprehensive co-expression network reveals the fine-tuning of AsHSFA2c in balancing drought tolerance and growth in oat.

Persistent activation of drought tolerance is detrimental to plant growth and development. However, the mechanism that balances plant drought tolerance and growth remains largely undetermined. Here, we constructed a comprehensive co-expression network comprising 84 transcriptome datasets associated with growth and drought tolerance in oats. Moreover, 84 functional modules and many candidate genes related to drought tolerance and growth were identified. A key candidate gene, AsHSFA2c was involved in fine-tuning the balance between drought tolerance and growth by inhibiting plant growth and positively regulating drought tolerance. Then, we determined AsDOF25 as an upstream positive regulator and AsAGO1 as the downstream target gene of AsHSFA2c. These results imply that the AsDOF25-AsHSFA2c-AsAGO1 module contributes to the balance between drought tolerance and growth in oats. Our findings and resources will facilitate the identification of key genes related to drought tolerance and further studies of the genetic basis underlying strong drought tolerance in oats.