Temporal and spatial transcriptomic and microRNA dynamics of CAM photosynthesis in pineapple

Plant J. 2017 Oct;92(1):19-30. doi: 10.1111/tpj.13630. Epub 2017 Aug 21.


The altered carbon assimilation pathway of crassulacean acid metabolism (CAM) photosynthesis results in an up to 80% higher water-use efficiency than C3 photosynthesis in plants making it a potentially useful pathway for engineering crop plants with improved drought tolerance. Here we surveyed detailed temporal (diel time course) and spatial (across a leaf gradient) gene and microRNA (miRNA) expression patterns in the obligate CAM plant pineapple [Ananas comosus (L.) Merr.]. The high-resolution transcriptome atlas allowed us to distinguish between CAM-related and non-CAM gene copies. A differential gene co-expression network across green and white leaf diel datasets identified genes with circadian oscillation, CAM-related functions, and source-sink relations. Gene co-expression clusters containing CAM pathway genes are enriched with clock-associated cis-elements, suggesting circadian regulation of CAM. About 20% of pineapple microRNAs have diel expression patterns, with several that target key CAM-related genes. Expression and physiology data provide a model for CAM-specific carbohydrate flux and long-distance hexose transport. Together these resources provide a list of candidate genes for targeted engineering of CAM into C3 photosynthesis crop species.

Keywords: Ananas comosus; CAM photosynthesis; circadian regulation; cis-element; stomata.

MeSH terms

  • Ananas / genetics*
  • Ananas / physiology
  • Carbon / metabolism*
  • Circadian Clocks
  • Gene Expression Regulation, Plant*
  • MicroRNAs / genetics*
  • Photosynthesis
  • Plant Proteins / genetics*
  • Plant Stomata / genetics
  • Plant Stomata / physiology
  • RNA, Plant / genetics
  • Transcriptome*
  • Water / metabolism


  • MicroRNAs
  • Plant Proteins
  • RNA, Plant
  • Water
  • Carbon