Characterization and analysis of the promoter region of monodehydroascorbate reductase 4 (CpMDAR4) in papaya

Dessireé Zerpa-Catanho, Steven J. Clough, Ray Ming

Research output: Contribution to journalArticlepeer-review


Key message: Differential spatial and temporal expression patterns due to regulatory cis-elements and two different isoforms are detected among CpMDAR4 alleles in papaya. Abstract: The aim of this research was to study the effects of cis-element differences between the X, Y and Yh alleles on the expression of CpMDAR4, a potential candidate gene for sex differentiation in papaya, using a transcriptional reporter system in a model species Arabidopsis thaliana. Possible effects of a retrotransposon insertion in the Y and Yh alleles on the transcription and expression of CpMDAR4 alleles in papaya flowers were also examined. When comparing promoters and cis-regulatory elements among genes in the non-recombining region of the sex chromosomes, paired genes exhibited differences. Our results showed that differences in the promoter sequences of the CpMDAR4 alleles drove the expression of a reporter gene to different flower tissues in Arabidopsis. β-glucuronidase staining analysis of T2 and T3 lines for constructs containing 5′ deletions of native Y and Yh allele promoters showed the loss of specific expression of the reporter gene in the anthers, confirming the existence and location of cis-regulatory element POLLEN1LELAT52. The expression analysis of CpMDAR4 alleles in papaya flowers also showed that all alleles are actively expressed in different flower tissues, with the existence of a shorter truncated isoform, with unknown function, for the Y and Yh alleles due to an LTR-RT insertion in the Y and Yh chromosomes. The observed expression patterns in Arabidopsis thaliana flowers and the expression patterns of CpMDAR4 alleles in papaya flowers suggest that MDAR4 might have a role on development of reproductive organs in papaya, and that it constitutes an important candidate for sex differentiation.

Original languageEnglish (US)
Pages (from-to)233-264
Number of pages32
JournalPlant Reproduction
Issue number4
StatePublished - Dec 2022


  • Carica papaya
  • Cis-elements
  • Isoforms
  • Monodehydroascorbate reductase
  • Promoter analysis

ASJC Scopus subject areas

  • Plant Science
  • Cell Biology


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