Effect of biotin deficiency on gene expression in Aravbidopsis leaves

In addition to its essential metabolic functions biotin is suggested a critical role in regulating gene expression. The first committed enzyme in biotin biosynthesis in Arabidopsis, 7-keto-8-aminopelargonic acid synthase is encoded by At5g04620 (BIO4). We isolated a novel T-DNA insertion mutant of BIO4 (bio4-1) showing a spontaneous cell death phenotype that could be rescued both by exogenous biotin and genetic complementation. The bio4-1 plants exhibited massive accumulation of hydrogen peroxide. The T-DNA insertion in the bio4-1 mutant contains a Methionine Sulfoxide Reductase B9 (AT4G21850) under a constitutive 35S CaMV promoter. To dissect the specific effects of biotin defiency on gene expression on a genome wide scale, we compared expression of wt Col-0 leaves with bio4-1 mutants and bio4-1 mutants complemented with D-biotin. Expression in leaves of Col-0 wt, bio4-1 mutants with a T-DNA insertion in the 5`-UTR of BIO4, and bio4-1 mutants complemented with watering with 200µM D-biotin.