Biology subjects

Giachero, M. L.

Publications and source records attributed to Giachero, M. L..

3 recordsLinked to original sources

bioRxiv2024

Analysis arbuscular mycorrhizal fungi (AMF) community composition associated with alkaline saline sodic soils

Marginal soils affected by salinity, sodicity and alkalinity decrease crop productivity. In this context, a viable alternative strategy lies in the remediation of degraded lands using beneficial microorganisms. This study aims to characterize native arbuscular mycorrhizal fungal (AMF) communities by sequencing PCR amplicons that cover most of the small subunit rRNA (SSU) gene, the complete internal transcribed spacer (ITS) region, and a portion of the large subunit (LSU) rRNA, employing Oxford Nanopore Technologies (ONT). Three field sites, with varying crop conditions, were selected: a patch with no crop growth (Site 1), a patch with corn stubble (Site 2), and a patch with wheat plants exhibiting 15 days of growth (Site 3). Soil analyses revealed distinct characteristics - alkaline saline sodic soil (ASS) for Site 1, moderately alkaline soil (A) for Site 2, and neutral soil (N) for Site 3. ONT sequencing yielded a total of 4,040,470 raw reads from which 19.13% survived after quality and length filter. Reads were grouped in 556 clusters, of which 222 remained after bioinformatic analysis. Despite moderate error rates in 9.4.1, flowcells chemistry, using a clustering and polishing approach facilitated the ecological analysis and allowed a better taxonomic resolution. Bioinformatic analysis showed no significant differences in AMF diversity among soils. However, results suggest the dominance of Glomeraceae and Acaulosporaceae families, specifically the genera Glomus and Acaulospora in ASS soil. Further exploration is required to better understand their role in promoting plant growth under adverse conditions. The study highlights the significance of cutting-edge sequencing tools in advancing the comprehension of essential symbiotic relationships for sustainable agriculture in challenging environments.

plant biology↗

bioRxiv2022

SOYBEAN RESPONSE TO INITIAL STAGE OF Fusarium virguliforme INFECTION

Fusarium virguliforme causes the Sudden Death Syndrome, an important disease in soybean crops. In this work, we investigated the defensive response mechanisms in soybean root, at cell wall level, during F. virguliforme infection using an in vitro culture system. We measured total root lignin content by the acetyl bromide method and estimated the in-situ lignin and suberin deposition by confocal microscopy on local and systemic root tissues, i.e. adjacent and distant to the pathogen entry site respectively. Moreover, the expression dynamics of phenylalanine ammonia lyase (PAL), shikimate/quinate hydroxycinnamoyltransferase (HCT) and cinnamyl alcohol dehydrogenase (CAD) was evaluated by real-time quantitative PCR. The results showed that, although the most significant increment of lignin deposition was observed in the epidermal cells of local tissues, F. virguliforme also induced lignin deposition changes in a sistemic fashion. In fact, inoculated plants presented a higher deposition of lignin in hypodermis and cortex than the control ones, independently of the distance from the inoculum source, while suberin deposition was higher in local zones. Moreover, the gene expression analysis showed an up-regulation of PAL, HCT and CAD genes after the inoculation with the pathogen, which correlates with the cell wall modifications observed in the local tissues. The results presented here suggest that the increase in lignin and suberin deposition during soybean root/F. virguliforme interaction is probably a strategy not only to stop the pathogen entrance, but to provide the plant more time to prepare its defences as well.

plant biology↗

bioRxiv2018

Transcriptome analysis of mycorrhizal and non-mycorrhizal soybean plantlets upon infection with Fusarium virguliforme, one causal agent of sudden death syndrome

Soilborne pathogens represent a threat to agriculture causing important yield losses. The \"Sudden Death Syndrome\" (SDS), a severe disease in soybean is caused by a complex of Fusarium species. This pathosystem has been widely investigated and several strategies were proposed to manage SDS. Although a decrease in symptoms and in the level of root tissue infection particularly by F. virguliforme was observed in presence of arbuscular mycorrhizal fungi (AMF), biological control based on AMF has received less attention. Here we report the results, under strict in vitro culture experimental conditions, a transcriptional analysis in mycorrhizal versus non-mycorrhizal soybean plantlets upon infection by F. virguliforme. An important transcriptional reprogramming was detected following infection by the pathogen. Results revealed 1768 and 967 differentially expressed genes in the AMF-colonized (+AMF+Fv) and non-colonized (-AMF+Fv) plants, respectively. Major transcriptional changes, corresponded to defence response related genes belonging to secondary metabolism, stress and signalling categories. The +AMF+Fv treatment showed the largest number of upregulated genes related to defence, as those encoding for disease resistance proteins, WRKY transcription factors, auxins, receptors kinases, and proteases. Only few genes had primed expression in +AMF+Fv treatment, as those coding for a thaumatin-like protein (TLP) and a pleiotropic drug resistance (PDR) protein. Moreover, +AMF+Fv showed a significant number of downregulated genes related to cell wall modification and peroxidases than - AMF+Fv treatment. This detailed insight increases our knowledge on the transcriptional changes and the potential metabolic pathways involved in the enhanced resistance/tolerance of mycorrhizal plants upon infection with F. virguliforme.

plant biology↗