Arabidopsis plants harbouring a mutation in AtSUC2, encoding the predominant sucrose/proton symporter necessary for efficient phloem transport, are able to complete their life cycle and produce viable seed.

Background And Aims: AtSUC2 encodes a sucrose/proton symporter that localizes throughout the collection and transport phloem and is necessary for efficient transport of sucrose from source to sink tissues in Arabidopsis thaliana. Plants harbouring homozygous AtSUC2 null alleles accumulate sugar, starch, and anthocyanin in mature leaves, have severely delayed development and stunted growth and, in previous studies, failed to complete their life cycle by producing viable seed.

Methods: An AtSUC2 allele with a T-DNA insertion in the second intron was analysed.