Characterization and map-based cloning of miniature2-m1, a gene controlling kernel size in maize

Characterization and map-based cloning of miniature2-m1, a gene controlling kernel size in maize

Blog Article

Kernel development plays an important role in determining kernel size in maize.Here we present the cloning and characterization of a maize gene, nitrate transporter1.5 wella color touch 77 45 (NRT1.5), which controls small kernel phenotype by playing an important role in kernel development.

A novel recessive small kernel mutant miniature2-m1 (mn2-m1) was isolated from self-pollinated progenies of breeding materials.The mutant spontaneously showed small kernel character arresting both embryo and endosperm development at an early stage after pollination.Utilizing 21 polymorphic SSR markers, the mn2-m1 locus was limited to a 209.9-kb interval using 9 176 recessive individuals of a BC1 segregating population from mn2-m1/B73.

Only one annotated gene was located in this 209.9 kb region, Zm00001d019294, which was predicted to encode nitrate transporter1.5 (NRT1.5).

Allelism tests confirmed that mn2-m1 was allelic to miniature2-m2 (mn2-m2) and miniature2-710B (mn2-710B).The mn2-m1 and mn2-m2 alleles both had nucleotide deletions in the coding region resulting in premature termination, and the mn2-710B allele had some missence mutations.Subcellular localization showed that Miniature 2 (MN2) is localized in the plasma membrane.Quantitative real-time PCR (qRT-PCR) analysis revealed that the expression of MN2 and some genes involved in the basal endosperm transfer layer (BETL) and embryo surrounding region (ESR) development were affected in mn2-m1 seeds.

These read more results suggested that MN2 plays an important role in maize seed development.