The role of barren stalk1 in the architecture of maize

Abstract

The architecture of higher plants is established through the activity of lateral meristems--small groups of stem cells formed during vegetative and reproductive development. Lateral meristems generate branches and inflorescence structures, which define the overall form of a plant, and are largely responsible for the evolution of different plant architectures. Here, we report the isolation of the barren stalk1 gene, which encodes a non-canonical basic helix-loop-helix protein required for the initiation of all aerial lateral meristems in maize. barren stalk1 represents one of the earliest genes involved in the patterning of maize inflorescences, and, together with the teosinte branched1 gene, it regulates vegetative lateral meristem development. The architecture of maize has been a major target of selection for early agriculturalists and modern farmers, because it influences harvesting, breeding strategies and mechanization. By sampling nucleotide diversity in the barren stalk1 region, we show that two haplotypes entered the maize gene pool from its wild progenitor, teosinte, and that only one was incorporated throughout modern inbreds, suggesting that barren stalk1 was selected for agronomic purposes.

Direct mapping of density response in a population of B73 × Mo17 recombinant inbred lines of maize (Zea Mays L.)

“…The two QTL for ears per plant detected in the Mo17 backcross in Stuber et al (1992) mapped around the QTL for ear per plant on chromosomes 7 and 8 in our study. Finally, the barren stalk1 locus, at which mutant alleles can eliminate the production of female inflorescenses (Gallavotti et al, 2007), is located near the major barrenness and yield QTL on chromosome 3, suggesting that this locus may also contribute to natural variation for barrenness in maize. Overlapping QTL in barrenness and grain yield suggest possible genetic mechanisms for carbon allocation as may be expected ).…”

Combining population genomics and quantitative genetics: finding the genes underlying ecologically important traits

“…Existing evidence suggests that it is possible and even probable for some loci to show high levels of differentiation (or reduced within population variation) without having been targets of selection either owing to chance alone, or for instance, due to incorrect models of demographic history used in estimating parameters like F ST (e.g., island versus stepping stone models; see Akey et al, 2004) or ascertainment bias (Thornton and Jensen, in press). Similarly, it is also possible for loci to be under selection without yielding statistically significant results in tests for selection (Gallavotti et al, 2004;McVean et al, 2005;Przeworski et al, 2005;Teshima et al, 2006). Simulation studies by Teshima et al (2006) suggest that a sizable proportion of loci under selection will be missed in empirical genome-wide scans, especially if the loci selected had previously been neutral.…”

Hormonal Regulation of Branching in Grasses

“…Yeast two-hybrid screening with PID identified calciumbinding proteins that act upstream of PID (Benjamins et al, 2003). In contrast, a yeast two-hybrid screen with BIF2 identified BARREN STALK1 (BA1), a nuclear localized basic helix-loop-helix putative transcription factor as an interacting partner with BIF2 (Gallavotti et al, 2004;Skirpan et al, 2008). In vitro kinase assays showed that BIF2 phosphorylates BA1 (Skirpan et al, 2008).…”