Targeted degradation of endogenous condensation-prone proteins improves crop performance

Abstract

Effective methods, such as CRISPR and RNA interference, exist for modulating gene expression at DNA and RNA levels, but approaches for directly modifying endogenous proteins remain lacking in plants. Here, we develop a targeted condensation-prone-protein degradation (TCD) strategy to eliminate endogenous proteins, particularly those prone to condensation. We identify an E3 ligase, E3TCD1, that degrades itself but selectively targets other proteins when fused to them. In rice, transgenic E3TCD1 fusions with Teosinte branched 1 and Early flowering 3 (OsELF3) modulate tiller numbers and flowering times, respectively. The TCD system is also controllable. Using the ProTBF1-uORFsTBF1 expression control cassette, we can conditionally degrade the negative defense regulator OsELF3 upon pathogen invasion, enhancing rice resistance without interfering with rice flowering time. This method, unlike animal-targeting strategies, does not rely on small molecules, antibodies, or genetic knock-ins, showing promise as a gene therapeutic avenue for optimizing crop performance and potentially addressing human diseases.