The chloroplast min system functions differentially in two specific nongreen plastids in Arabidopsis thaliana

PLoS One. 2013 Jul 30;8(7):e71190. doi: 10.1371/journal.pone.0071190. Print 2013.

Abstract

The nongreen plastids, such as etioplasts, chromoplasts, etc., as well as chloroplasts, are all derived from proplastids in the meristem. To date, the Min system members in plants have been identified as regulators of FtsZ-ring placement, which are essential for the symmetrical division of chloroplasts. However, the regulation of FtsZ-ring placement in nongreen plastids is poorly understood. In this study, we investigated the division site placement of nongreen plastids by examining the etioplasts as representative in Arabidopsis Min system mutants. Surprisingly, the shape and number of etioplasts in cotyledons of arc3, arc11 and mcd1 mutants were similar to that observed in wild-type plants, whereas arc12 and parc6 mutants exhibited enlarged etioplasts that were reduced in number. In order to examine nongreen plastids in true leaves, we silenced the ALB3 gene in these Min system mutant backgrounds to produce immature chloroplasts without the thylakoidal network using virus induced gene silencing (VIGS). Interestingly, consistent with our observations in etioplasts, enlarged and fewer nongreen plastids were only detected in leaves of parc6 (VIGS-ALB3) and arc12 (VIGS-ALB3) plants. Further, the FtsZ-ring assembled properly at the midpoint in nongreen plastids of arc3, arc11 and mcd1 (VIGS-ALB3) plants, but organized into multiple rings in parc6 (VIGS-ALB3) and presented fragmented filaments in arc12 (VIGS-ALB3) plants, suggesting that division site placement in nongreen plastids requires fewer components of the plant Min system. Taken together, these results suggest that division site placement in nongreen plastids is different from that in chloroplasts.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Arabidopsis / genetics*
  • Arabidopsis / metabolism*
  • Arabidopsis Proteins / genetics*
  • Arabidopsis Proteins / metabolism*
  • Chloroplasts / genetics*
  • Chloroplasts / metabolism*
  • Gene Expression Regulation, Plant
  • Mutation
  • Phenotype
  • Plant Leaves / genetics
  • Plant Leaves / metabolism
  • Plastids / genetics
  • Plastids / metabolism

Substances

  • Arabidopsis Proteins

Grants and funding

This investigation was supported by the National Natural Science Foundation of China (No. 31171173), the Natural Science Foundation of Guangdong Province, PR China (No. S2012010010533), the Fundamental Research Funds for the Central Universities (10lgpy34), and the Open Research Fund Program of Guangdong Key Laboratory of Plant Resources (plant01k18). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.