Phenotypic characterization of Arabidopsis thaliana mutants that alleviate root growth defects in a vitamin B ₆ biosynthesis mutant

Vitamin B 6 is an essential metabolite required by all living organisms and participates in numerous cellular biochemical reactions. Unlike mammals, plants can synthesize this compound de novo , and therefore, serve as an excellent nutritional source for the vitamin. Although the biosynthesis pathway in plants has been well understood for nearly two decades, the regulatory mechanisms that control vitamin B 6 levels remain largely unknown. Here, we describe a novel set of Arabidopsis mutants that display distinct phenotypic and molecular characteristics and are likely affected in either the biosynthesis or homeostasis of vitamin B 6 . We propose that these new mutants will serve as valuable tools for uncovering the unknown regulatory steps governing vitamin B 6 levels in plants.