abstract: many transcription factors (tfs) in animals bind to both dna and mrna, regulating transcription and mrna turnover. however, whether plant tfs function at both the transcriptional and post-transcriptional levels remains unknown. the rice (oryza sativa) bzip tf avrpiz-t-interacting protein 5 (apip5) negatively regulates programmed cell death and blast resistance and is targeted by the effector avrpiz-t of the blast fungus magnaporthe oryzae. we demonstrate that the nuclear localization signal of apip5 is essential for apip5-mediated suppression of cell death and blast resistance. apip5 directly targets two genes that positively regulate blast resistance: the cell wall-associated kinase gene oswak5 and the cytochrome p450 gene cyp72a1. apip5 inhibits oswak5 expression and thus limits lignin accumulation; moreover, apip5 inhibits cyp72a1 expression and thus limits reactive oxygen species production and defense compounds accumulation. remarkably, apip5 acts as an rna-binding protein to regulate mrna turnover of the cell death- and defense-related genes oslsd1 and osrac1. therefore, apip5 plays dual roles, acting as tf to regulate gene expression in the nucleus and as an rna-binding protein to regulate mrna turnover in the cytoplasm, a previously unidentified regulatory mechanism of plant tfs at the transcriptional and post-transcriptional levels.
nucleic acids research， if：16.97
doi：doi.org/10.1093/nar/gkac316
