The control of maize spikelet meristem fate by theAPETALA2-like gene indeterminate spikelet1 (original) (raw)

  1. George Chuck,
  2. Robert B. Meeley, and
  3. Sarah Hake
  4. Department of Plant and Microbial Biology, University of California, Berkeley, California 94720, USA; Pioneer Hi-Bred International, Johnston, Iowa 50131, USA; Plant Gene Expression Center, US Department of Agriculture-Agricultural Research Service (USDA-ARS), Albany, California 94710, USA

Abstract

The orderly production of meristems with specific fates is crucial for the proper elaboration of plant architecture. The maize inflorescence meristem branches several times to produce lateral meristems with determinate fates. The first meristem formed, the spikelet pair meristem, produces two spikelet meristems, each of which produces two floral meristems. We have identified a gene called_indeterminate spikelet1_ (ids1) that specifies a determinate spikelet meristem fate and thereby limits the number of floral meristems produced. In the absence of ids1 gene function, the spikelet meristem becomes indeterminate and produces additional florets. Members of the grass family vary in the number of florets within their spikelets, suggesting that ids1 may play a role in inflorescence architecture in other grass species. ids1_is a member of the APETALA2 (AP2) gene family of transcription factors that has been implicated in a wide range of plant development roles. Expression of_ids1 was detected in many types of lateral organ primordia as well as spikelet meristems. Our analysis of the ids1 mutant phenotype and expression pattern indicates that ids1 specifies determinate fates by suppressing indeterminate growth within the spikelet meristem.

Footnotes