Interplay of SLIM1 and miR395 in the regulation of sulfate assimilation in Arabidopsis

Cintia G. Kawashima, Colette A. Matthewman, Siqi Huang, Bok-Rye Lee, Naoko Yoshimoto, Anna Koprivova, Ignacio Rubio-Somoza, Marco Todesco, Tina Rathjen, Kazuki Saito, Hideki Takahashi, Tamas Dalmay, Stanislav Kopriva

Research output: Contribution to journalArticlepeer-review

142 Citations (Scopus)

Abstract

MicroRNAs play a key role in the control of plant development and response to adverse environmental conditions. For example, microRNA395 (miR395), which targets three out of four isoforms of ATP sulfurylase, the first enzyme of sulfate assimilation, as well as a low-affinity sulfate transporter, SULTR2;1, is strongly induced by sulfate deficiency. However, other components of sulfate assimilation are induced by sulfate starvation, so that the role of miR395 is counterintuitive. Here, we describe the regulation of miR395 and its targets by sulfate starvation. We show that miR395 is important for the increased translocation of sulfate to the shoots during sulfate starvation. MiR395 together with the SULFUR LIMITATION 1 transcription factor maintain optimal levels of ATP sulfurylase transcripts to enable increased flux through the sulfate assimilation pathway in sulfate-deficient plants. Reduced expression of ATP sulfurylase (ATPS) alone affects both sulfate translocation and flux, but SULTR2;1 is important for the full rate of sulfate translocation to the shoots. Thus, miR395 is an integral part of the regulatory circuit controlling plant sulfate assimilation with a complex mechanism of action.
Original languageEnglish
Pages (from-to)863-876
Number of pages14
JournalThe Plant Journal
Volume66
Issue number5
DOIs
Publication statusPublished - Jun 2011

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