Magnesium supply alleviates iron toxicity-induced leaf bronzing in rice through exclusion and tissue-tolerance mechanisms

Introduction Iron (Fe) toxicity is a widespread nutritional disorder in lowland rice causing growth retardation and leaf symptoms referred to as bronzing. It partly caused by an imbalance of nutrients other than Fe supply these known mitigate the toxicity. But physiological molecular mechanisms involved are unknown. Methods We investigated effect magnesium (Mg) on tolerance field study Central Highlands Madagascar hydroponic experiments with excess (300 mg L -1 ). An RNA-seq analysis was conducted experiment elucidate possible underlying Mg effects. Results discussion Addition consistently decreased bronzing under both conditions, whereas potassium (K) addition minor Plants treated tended have smaller shoot concentrations field, suggesting enhanced exclusion at whole-plant level. However, multiple genotypes showed that were also mitigated without concomitant decrease concentration, increased confers tissue The suggested significantly decreasing concentration or oxidative stress assessed content malondialdehyde, biomarker for stress. revealed induced more changes leaves roots. Subsequent cis-element NAC transcription factor binding sites enriched genes leaves. non-significant enrichment same sites, family proteins may mediate Mg. This provides clues mitigating toxicity-induced rice.