The arbuscular mycorrhizal status has an impact on the transcriptome profile and amino acid composition of tomato fruit

Abstract

BackgroundArbuscular mycorrhizal (AM) symbiosis is the most widespread association between plant roots and fungi in natural and agricultural ecosystems. This work investigated the influence of mycorrhization on the economically relevant part of the tomato plant, by analyzing its impact on the physiology of the fruit. To this aim, a combination of phenological observations, transcriptomics (Microarrays and qRT-PCR) and biochemical analyses was used to unravel the changes that occur on fruits from Micro-Tom tomato plants colonized by the AM fungus Glomus mosseae.ResultsMycorrhization accelerated the flowering and fruit development and increased the fruit yield. Eleven transcripts were differentially regulated in the fruit upon mycorrhization, and the mycorrhiza-responsive genes resulted to be involved in nitrogen and carbohydrate metabolism as well as in regulation and signal transduction. Mycorrhization has increased the amino acid abundance in the fruit from mycorrhizal plants, with glutamine and asparagine being the most responsive amino acids.ConclusionsThe obtained results offer novel data on the systemic changes that are induced by the establishment of AM symbiosis in the plant, and confirm the work hypothesis that AM fungi may extend their influence from the root to the fruit.

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

“…1). As expected, under AM colonization, the Ailsa Craig WT plants accelerated the floral transition, as previously observed in the Micro-Tom cv (Salvioli et al 2012). For most of the mutants considered no statistically supported differences between MYC and NM were observed.…”

“…While mycorrhiza is not impacted in its establishment by altered fruit ET response or whole plant light response, perturbing these signaling systems has an impact on plant phenology both under MYC and NM conditions. Previous investigations performed using Micro-Tom tomatoes colonized by F. mosseae revealed a positive correlation between AM, systemic effects and phenology (Salvioli et al 2012). Ailsa Craig cv MYC WT confirmed this trend having a significantly reduced vegetative period.…”

“…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).…”

“…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). In addition, they possess a higher anti-oestrogenic power and no in vitro genotoxic effects (Giovannetti et al 2012), as well as an enhanced expression of allergen-encoding genes that do not match with a higher allergenic potential for humans (Schwarz et al 2011).…”

Symbiosis with an endobacterium increases the fitness of a mycorrhizal fungus, raising its bioenergetic potential

“…The samples were then reverse-transcribed using Superscript II Reverse Transcriptase (Life Technologies). Quantitative realtime PCR experiments and data analysis were carried out as described in Salvioli et al (2012), using as a reference gene for transcript normalisation the G. margarita elongation factor (Tef). The primer names and corresponding sequences are listed in Supplementary Table S10.…”