Sexual Plant Reproduction

, Volume 16, Issue 6, pp 289–297

Transcript profiling of male-fertile and male-sterile sorghum indicates extensive alterations in gene expression during microgametogenesis

Original Article

DOI: 10.1007/s00497-004-0204-1

Cite this article as:
Pring, D.R. & Tang, H.V. Sex Plant Reprod (2004) 16: 289. doi:10.1007/s00497-004-0204-1

Abstract

Male-sterile sorghum carrying the IS1112C cytoplasm represents an unusual example of aberrant microgametogenesis wherein microspores develop into inviable pollen that remain physically intact until anther exsertion. These inviable pollen grains do not deposit starch, yet fluoresce with the vital stain fluoroscein diacetate. We sought to elucidate the extent of differential gene expression in this subtle example of defective microgametogenesis through cDNA-AFLP transcript profiling of near-isogenic male-fertile and male-sterile plants at an early stage representing early-mid microspores to early pollen, 7–11 days prior to anthesis, and a late stage representing young to nearly mature pollen, spanning the terminal 96 h of pollen development. The transition from early to late stages is characterized by changes in abundance of nearly 33% of shared transcripts, and early- or late-specific expression of about 10% of transcripts. Male-sterile plants exhibit extensive changes in regulatory patterns characteristic of fertile plants, including premature expression of late-specific, and prolonged expression of early-specific, transcripts. Genome-wide transcriptome patterns indicate the expression of an estimated 12,000 genes in early-mid microspores, and the abundance of at least 15% of these transcripts is altered in male-sterile plants. A near-isogenic line restored to male fertility is characterized by apparent normalized expression of most of these transcripts. The development of the microgametophyte is thus characterized by dynamic programmed changes in gene expression, and the expression of male sterility compounds these changes in a complex manner.

Keywords

SorghumCytoplasmic male sterilityRestorer genesTranscript profiling

Copyright information

© Springer-Verlag 2004

Authors and Affiliations

  1. 1.United States Department of Agriculture-Agricultural Research Service, Department of Plant PathologyUniversity of FloridaGainesville USA