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Identification of Plasmodesmal Localization Sequences in Proteins In Planta
08:07

Identification of Plasmodesmal Localization Sequences in Proteins In Planta

Published on: August 15, 2017

Phytoplasma PMU1 exists as linear chromosomal and circular extrachromosomal elements and has enhanced expression in

Tania Y Toruño1, Martina Seruga Musić, Silvia Simi

  • 1Department of Entomology, The Ohio State University-Ohio Agricultural Research and Development Center (OARDC), Wooster, OH 44691, USA.

Molecular Microbiology
|July 29, 2010
PubMed

Insights

Phytoplasmas utilize potential mobile units (PMUs) for host adaptation. The circular PMU1 is more abundant and expressed in insects, suggesting regulated replication and host-specific roles in phytoplasma virulence.

Area of Science:

  • Microbiology
  • Plant Pathology
  • Genetics

Background:

  • Phytoplasmas are obligate intracellular bacteria dependent on plant and insect hosts.
  • Their small genomes possess multicopy gene clusters known as potential mobile units (PMUs).
  • PMU1, a large repeat in Aster Yellows phytoplasma strain Witches' Broom (AY-WB), contains genes for DNA replication and membrane proteins.

Purpose of the Study:

  • To investigate the structure and regulation of PMU1 in AY-WB.
  • To determine the distribution and expression of PMU1 in different hosts (insects vs. plants).
  • To explore the role of PMUs in phytoplasma host adaptation and virulence.

Main Methods:

  • Comparative analysis of linear (L-PMU1) and circular (C-PMU1) forms of PMU1.
  • Quantification of C-PMU1 copy number in insect and plant hosts.
  • Analysis of PMU1 gene expression levels in different hosts.
  • Genomic localization of virulence genes within PMU regions.

Main Results:

  • AY-WB possesses both L-PMU1 and C-PMU1 forms.
  • C-PMU1 copy number was approximately fivefold higher in insects compared to plants.
  • PMU1 gene expression was significantly elevated in insects, indicating regulated synthesis and expression.
  • Crucial AY-WB virulence genes are located on chromosomal PMU regions similar to PMU1.

Conclusions:

  • PMUs, particularly C-PMU1, play a significant role in phytoplasma host adaptation.
  • The differential regulation of C-PMU1 in insects suggests host-specific functions.
  • PMUs have integrated into the AY-WB chromosome, contributing to its adaptive potential.

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