Transcriptional trajectories of anther development provide candidates for engineering male fertility in sorghum

Sci Rep. 2020 Jan 21;10(1):897. doi: 10.1038/s41598-020-57717-0.

Abstract

Sorghum is a self-pollinated crop with multiple economic uses as cereal, forage, and biofuel feedstock. Hybrid breeding is a cornerstone for sorghum improvement strategies that currently relies on cytoplasmic male sterile lines. To engineer genic male sterility, it is imperative to examine the genetic components regulating anther/pollen development in sorghum. To this end, we have performed transcriptomic analysis from three temporal stages of developing anthers that correspond to meiotic, microspore and mature pollen stages. A total of 5286 genes were differentially regulated among the three anther stages with 890 of them exhibiting anther-preferential expression. Differentially expressed genes could be clubbed into seven distinct developmental trajectories using K-means clustering. Pathway mapping revealed that genes involved in cell cycle, DNA repair, regulation of transcription, brassinosteroid and auxin biosynthesis/signalling exhibit peak expression in meiotic anthers, while those regulating abiotic stress, carbohydrate metabolism, and transport were enriched in microspore stage. Conversely, genes associated with protein degradation, post-translational modifications, cell wall biosynthesis/modifications, abscisic acid, ethylene, cytokinin and jasmonic acid biosynthesis/signalling were highly expressed in mature pollen stage. High concurrence in transcriptional dynamics and cis-regulatory elements of differentially expressed genes in rice and sorghum confirmed conserved developmental pathways regulating anther development across species. Comprehensive literature survey in conjunction with orthology analysis and anther-preferential accumulation enabled shortlisting of 21 prospective candidates for in-depth characterization and engineering male fertility in sorghum.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Carbohydrate Metabolism / genetics
  • Cell Wall / genetics
  • Cell Wall / metabolism
  • Flowers / genetics*
  • Flowers / growth & development*
  • Flowers / metabolism
  • Gene Expression Regulation, Plant
  • Genetic Engineering
  • Genomics
  • Meiosis / genetics
  • Oryza / genetics
  • Plant Growth Regulators / genetics
  • Plant Growth Regulators / metabolism
  • Plant Infertility / genetics
  • Plant Proteins / genetics*
  • Plants, Genetically Modified
  • Pollen / cytology
  • Pollen / genetics
  • Pollen / growth & development
  • Pollen / metabolism
  • Reproducibility of Results
  • Secondary Metabolism / genetics
  • Sequence Analysis, RNA
  • Sorghum / genetics*
  • Sorghum / growth & development
  • Sorghum / metabolism

Substances

  • Plant Growth Regulators
  • Plant Proteins