Global and cell‐type gene expression profiles in tomato plants colonized by an arbuscular mycorrhizal fungus

Abstract

Summary• Arbuscular mycorrhizal symbiosis develops in roots; extensive cellular reorganizations and specific metabolic changes occur, which are mirrored by local and systemic changes in the transcript profiles.• A TOM2 microarray (c. 12 000 probes) has been used to obtain an overview of the transcriptional changes that are triggered in Solanum lycopersicum roots and shoots, as a result of colonization by the arbuscular mycorrhizal fungus Glomus mosseae. The cell-type expression profile of a subset of genes was monitored, using laser microdissection, to identify possible plant determinants of arbuscule development,.• Microarrays revealed 362 up-regulated and 293 down-regulated genes in roots. Significant gene modulation was also observed in shoots: 85 up-and 337 downregulated genes. The most responsive genes in both organs were ascribed to primary and secondary metabolism, defence and response to stimuli, cell organization and protein modification, and transcriptional regulation. Six genes, preferentially expressed in arbusculated cells, were identified.• A comparative analysis only showed a limited overlap with transcript profiles identified in mycorrhizal roots of Medicago truncatula, probably as a consequence of the largely nonoverlapping probe sets on the microarray tools used. The results suggest that auxin and abscisic acid metabolism are involved in arbuscule formation and ⁄ or functioning.

Gr and hp-1 tomato mutants unveil unprecedented interactions between arbuscular mycorrhizal symbiosis and fruit ripening

“…The treated RNA samples were then re-checked spectrophotometrically to determine the nucleic acid concentration, as previously described. The absence of DNA contamination was verified through amplification of a fragment of the tomato ubiquitin gene (Fiorilli et al 2009) in a control reverse-transcription PCR using the OneStep RT-PCR Kit (Qiagen), followed by agarose gel electrophoresis. cDNA was synthesized from 750 ng of total RNA using the SuperscriptTM II Reverse Transcriptase Kit (Invitrogen) according to the manufacturer's indications.…”

“…These genes regulate not only nutrient transport, but also carbohydrate and lipid metabolism as well as cell wall remodeling (Ruzicka et al 2013). Extending transcriptomic analysis to the whole plant, an organ-independent gene core set and a systemic defencerelated gene program have been detected in shoot and fruits, both induced by the presence of AMF (Fiorilli et al 2009;Salvioli et al 2012). Fruits from mycorrhizal (MYC) tomato plants have also been found to be enriched in healthy compounds, including amino acids (Salvioli et al 2012) and lycopene (Regvar et al 2003).…”

Indole-3-acetic acid: A widespread physiological code in interactions of fungi with other organisms

“…69 Genomic analysis of the expression profiles in tomato plants colonized by an arbuscular mycorrhizal fungus revealed the accumulation of transcripts for a putative IAA-amido synthetase in mycorrhizal roots. 70 The role of auxin signaling during AM has become more evident with regard to miRNA-mediated regulation. MicroRNA 393 (miR393) targets several auxin receptors.…”

Proteomic Analyses of Cells Isolated by Laser Microdissection

“…Recently, LM has also been used to provide new insight into fruit development and physiology through the collection of epidermal and subepidermal cells from green, expanding Citrus clementina fruit (Matas et al, 2010). A few studies have also focused on the application of LM to gene expression in plant-microbe interactions (Tang et al, 2006;Balestrini et al, 2007;Guether et al, 2009aGuether et al, , 2009bFiorilli et al, 2009;Chandran et al, 2010;Hacquard et al, 2010).…”