{'fraction_non_alphanumeric': 0.02178217821782178, 'fraction_numerical': 0.021122112211221122, 'mean_word_length': 5.064, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
STOP1 degradation mediated by the F-box proteins RAH1 and RAE1 balances aluminum resistance and plant growth in Arabidopsis thaliana.

The C2H2-type zinc finger transcription factor STOP1 is crucial for aluminum (Al) resistance in Arabidopsis. The F-box protein Regulation of AtALMT1 Expression 1 (RAE1) was recently reported to regulate the stability of STOP1. There is a unique homolog of RAE1, RAH1 (RAE1 homolog 1), in Arabidopsis, but the biological function of RAH1 is still known. In this study, we characterized the role of RAH1 and/or RAE1 in the regulation of Al resistance and plant growth. We demonstrate that RAH1 can directly interact with STOP1 and promote its ubiquitination and degradation. RAH1 is preferentially expressed in root caps and vascular tissues of various tissues, and its expression is induced by Al and controlled by STOP1. Mutation of RAH1 in rae1 but not wild-type (WT) background increases STOP1 protein level, leading to increased expression of STOP1-regulated genes and enhanced Al resistance. Interestingly, rah1rae1 double mutant shows reduced plant growth compared to WT and single mutants under normal conditions, and introduction of stop1 mutation into the double mutant background can rescue its reduced plant growth phenotype. Our results thus reveal that RAH1 plays an unequally redundant role with RAE1 in the modulation of STOP1 stability and plant growth, and dynamic regulation of the STOP1 level is critical for the balance of Al resistance and normal plant growth.