MicroRNA395 mediates regulation of sulfate accumulation and allocation in Arabidopsis thaliana

Plant J. 2010 Jun 1;62(6):1046-57. doi: 10.1111/j.1365-313X.2010.04216.x. Epub 2010 Mar 31.

Abstract

Sulfur is a macronutrient that is necessary for plant growth and development. Sulfate, a major source of sulfur, is taken up by plant roots and transported into various tissues for assimilation. During sulfate limitation, expression of miR395 is significantly up-regulated. miR395 targets two families of genes, ATP sulfurylases (encoded by APS genes) and sulfate transporter 2;1 (SULTR2;1, also called AST68), both of which are involved in the sulfate metabolism pathway. Their transcripts are suppressed strongly in miR395-over-expressing transgenic Arabidopsis, which over-accumulates sulfate in the shoot but not in the root. APS1 knockdown mutants accumulate twice as much sulfate as the wild-type. By constructing APS4-RNAi transgenic plants, we found that silencing the APS4 gene also results in over-accumulation of sulfate. Even though miR395-over-expressing transgenic plants over-accumulate sulfate in the shoot, they display sulfur deficiency symptoms. Additionally, the distribution of sulfate from older to younger leaves is impaired in miR395-over-expressing plants, similar to a SULTR2;1 loss-of-function mutant. The aps1-1 sultr2;1 APS4-RNAi triply repressed mutants phenocopied miR395-over-expressing plants. Our research showed that miR395 is involved in the regulation of sulfate accumulation and allocation by targeting APS genes and SULTR2;1, respectively.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anion Transport Proteins / metabolism
  • Arabidopsis / genetics*
  • Arabidopsis / metabolism
  • Arabidopsis Proteins / metabolism
  • DNA, Bacterial / genetics
  • Gene Expression Regulation, Plant
  • Gene Silencing
  • MicroRNAs / metabolism*
  • Mutagenesis, Insertional
  • Plant Leaves / metabolism
  • Plant Shoots / metabolism
  • Plants, Genetically Modified / genetics
  • Plants, Genetically Modified / metabolism
  • RNA, Plant / metabolism*
  • Sulfate Adenylyltransferase / metabolism
  • Sulfate Transporters
  • Sulfates / metabolism*

Substances

  • AST68 protein, Arabidopsis
  • Anion Transport Proteins
  • Arabidopsis Proteins
  • DNA, Bacterial
  • MicroRNAs
  • RNA, Plant
  • Sulfate Transporters
  • Sulfates
  • T-DNA
  • Sulfate Adenylyltransferase