Cooperative Regulatory Functions of miR858 and MYB83 during Cyst Nematode Parasitism.

Abstract

MicroRNAs (miRNAs) recently have been established as key regulators of transcriptome reprogramming that define cell function and identity. Nevertheless, the molecular functions of the greatest number of miRNA genes remain to be determined. Here, we report cooperative regulatory functions of miR858 and its MYB83 transcription factor target gene in transcriptome reprogramming during Heterodera cyst nematode parasitism of Arabidopsis (Arabidopsis thaliana). Gene expression analyses and promoter-GUS fusion assays documented a role of miR858 in posttranscriptional regulation of MYB83 in the Heterodera schachtii-induced feeding sites, the syncytia. Constitutive overexpression of miR858 interfered with H. schachtii parasitism of Arabidopsis, leading to reduced susceptibility, while reduced miR858 abundance enhanced plant susceptibility. Similarly, MYB83 expression increases were conducive to nematode infection because overexpression of a noncleavable coding sequence of MYB83 significantly increased plant susceptibility, whereas a myb83 mutation rendered the plants less susceptible. In addition, RNA-seq analysis revealed that genes involved in hormone signaling pathways, defense response, glucosinolate biosynthesis, cell wall modification, sugar transport, and transcriptional control are the key etiological factors by which MYB83 facilitates nematode parasitism of Arabidopsis. Furthermore, we discovered that miR858-mediated silencing of MYB83 is tightly regulated through a feedback loop that might contribute to fine-tuning the expression of more than a thousand of MYB83-regulated genes in the H. schachtii-induced syncytium. Together, our results suggest a role of the miR858-MYB83 regulatory system in finely balancing gene expression patterns during H. schachtii parasitism of Arabidopsis to ensure optimal cellular function.

• Authors: Sarbottam Piya, Christina Kihm, J Hollis Rice, Thomas J Baum, Tarek Hewezi
• Journal: Plant physiology (Plant Physiol) Vol. 174 Issue 3 Pg. 1897-1912 (Jul 2017) ISSN: 1532-2548 [Electronic] United States
• PMID: 28512179 (Publication Type: Journal Article)
• Copyright: © 2017 American Society of Plant Biologists. All Rights Reserved.

Chemical References

• Arabidopsis Proteins
• MYB83 protein, Arabidopsis
• MicroRNAs
• Mirn858 microRNA, Arabidopsis
• Transcription Factors
• Glucuronidase

Topics

• Animals
• Arabidopsis (genetics, parasitology)
• Arabidopsis Proteins (genetics, metabolism)
• Base Sequence
• Disease Resistance (genetics)
• Down-Regulation (genetics)
• Feedback, Physiological
• Gene Expression Profiling
• Gene Expression Regulation, Plant
• Gene Ontology
• Glucuronidase (metabolism)
• MicroRNAs (genetics, metabolism)
• Models, Biological
• Open Reading Frames (genetics)
• Parasites (physiology)
• Plant Diseases (genetics, parasitology)
• Plants, Genetically Modified
• Promoter Regions, Genetic (genetics)
• Transcription Factors (genetics, metabolism)
• Tylenchoidea (physiology)