Project description:RKNs are economically most damaging, obligate sedentary endoparasites that form giant cells within host roots to obtain nutrition and complete their life cycle. We report genome-wide identification of miRNAs from both host and RKN using RKN-infected susceptible tomato roots through high-throughput sequencing. Eleven small RNA libraries were made from five disease development stages, their five corresponding uninfected development stages and uninfected development stage 0. A total of 52 conserved miRNAs, 4 variants of conserved miRNAs and 281 novel miRNAs of host were identified. A significantly upregulated expression of majority of the miRNAs was observed during susceptible response and downregulated expression during resistance response through qRT-PCR. The miRNA targets were predicted and validated through 5’RLM-RACE. Furthermore, correlation between the expression profile of selected conserved miRNAs viz., miR164, miR156, miR396, miR159, and novel Sly_miRNA996 with their target transcription factors viz., NAC, SBP, GRF1, GAMYB-like, and MYB-like, respectively was also determined. This study suggests a potential role of host miRNAs in regulating transcription factor genes involved in plant developmental processes and defense responses during RKN infection. Additionally, 328 RKN miRNAs including 38 conserved miRNAs, 106 novel miRNAs, and 184 candidate novel miRNAs were identified from same dataset. The differential expression of conserved and RKN-specific miRNAs at different development stages of nematode in tomato roots suggests their probable role during nematode development and adaptation to parasitic behavior. This is the most comprehensive study reporting the identification and characterization of miRNAs from both tomato and RKN in five different disease development stages under soil grown conditions and their potential roles during RKN infection in tomato roots.
Project description:This study aimed to investigate the physiological and molecular responses of Solanum lycopersicum (tomato) to Phytophthora cinnamomi infection. The initial defense response in tomato seeds included the production of reactive oxygen species (ROS) and callose deposition. Screening of commercial tomato varieties revealed varying levels of susceptibility, with the variety Marmande exhibiting heightened vulnerability. Three days post-inoculation, Marmande showed increased expression of genes associated with ROS generation, and biosynthesis pathways for phenylpropanoids and flavonoids. Additionally, 850 genes related to cell wall remodeling, including those involved in lignin biosynthesis and pectin methyl esterase inhibitors (PMEIs), were significantly upregulated. Seven days post-inoculation, a stronger transcriptional response was observed, with activation of ethylene (ET) and jasmonic acid (JA) signaling pathways, while salicylic acid (SA) showed minimal activity. Metabolomic analysis of infected roots revealed elevated levels of metabolites linked to lycopene, flavonoids, and phenylpropanoids. Furthermore, infected roots exhibited a significant reduction in pectin levels, which was corroborated by in vitro assays showing zoospore-mediated pectin degradation. These results suggest that degradation of root pectin is a key mechanism facilitating zoospore invasion in susceptible tomato hosts. This study provides new insights into the molecular mechanisms underlying host-pathogen interactions and identifies potential targets for managing Phytophthora cinnamomi-induced diseases in crops.
Project description:Iron (Fe) deficiency is a yield-limiting factor for a variety of field crops across the world and generally results from the interaction of limited soil Fe bioavailability and susceptible genotype cultivation. Tomato, a Strategy I, model plant for Fe deficiency, is an important economical crop. Tomato responses in order to improve Fe uptake are based on acidification of rhizosphere, reduction of Fe3+ to Fe2+ and transport of Fe2+ into the cells. Transcriptional profile obtained by roots (27-d) of 21-d-old tomato plants starved of iron for an additional week was compared with the transcriptional profile obtained for roots (27-d) of 21-d-old tomato plants grown for an additional week at 100 M-NM-<M Fe. Tomato plants were hydroponically grown in both cases. Three different biological replicates were used for each sample repeating the experiment three times. All samples were obtained pooling roots of six plants (27-d-old).
Project description:To characterize the PTI response of tomato and the effect of the delivery of a subset of effectors, we performed an RNA-seq analysis of tomato Rio Grande prf3 leaves challenged with either the flgII-28 peptide or the following bacterial strains: Agrobacterium tumefaciens GV2260, Pseudomonas fluorescens 55, Pseudomonas putida KT2440, Pseudomonas syringae pv. tomato (Pst) DC3000, Pst DC3000 deltahrcQ-U deltafliC and Pst DC3000 deltaavrPto deltaavrPtoB. NOTE: Samples in SRA were assigned the same sample accession. This is incorrect as there are different samples, hence âSource Nameâ was replaced with new values. Comment[ENA_SAMPLE] contains the original SRA sample accessions.
Project description:The biocontrol agent Pythium oligandrum, which is a member of phylum Oomycota, can control diseases caused by a taxonomically wide range of plant pathogens, including fungi, bacteria, and oomycetes. However, whether P. oligandrum could control diseases caused by plant root-knot nematodes (RKNs) was unknown. We investigated a recently isolated P. oligandrum strain GAQ1, and the P. oligandrum CBS530.74 strain, for the control of RKN Meloidogyne incognita infection of tomato (Solanum lycopersicum L.). Initially, P. oligandrum culture filtrates were found to be lethal to M. incognita second-stage juveniles (J2s) with up to 84% mortality at 24 h after treatment compared to 14% in the control group. Consistent with the lethality to M. incognita J2s, tomato roots treated with P. oligandrum culture filtrates reduced the attraction of nematodes, and the number of nematodes penetrating the roots was reduced by up to 78%. In a greenhouse pot trial, P. oligandrum GAQ1 inoculation of tomato plants significantly reduced the gall number by 58% in plants infected with M. incognita. Notably, P. oligandrum GAQ1 mycelial treatment significantly increased tomato plant height (by 36%), weight (by 27%), and root weight (by 48%). Transcriptome analysis of tomato seedling roots inoculated with the P. oligandrum GAQ1 strain identified ~2,500 differentially expressed genes. The enriched GO terms and annotations in the up-regulated genes suggested modulation of plant hormone-signaling and defense-related pathways in response to P. oligandrum. In conclusion, our results support that P. oligandrum GAQ1 can serve as a potential biocontrol agent for M. incognita control in tomato. Multiple mechanisms appear to contribute to the biocontrol effect involving direct inhibition of M. incognita, potential priming of tomato plant defenses, and plant growth promotion.
Project description:Tomato, a Strategy I model plant for Fe deficiency, is an important economical crop. The transcriptional responses induced by Fe deficiency in tomato roots were previously described (Zamboni et al., 2012). The changes in trascriptome caused by the supply of Fe to plants starved fro 1 week were described in relation to the different nature of chelating agents (Fe-WEHS, Fe-CITRATE and Fe-PS). Transcriptional profile obtained by roots (27-d) of 21-d-old tomato plants starved of iron (0 μM Fe-EDTA) for 1 week and supplied for 1 h with 1 μM of Fe as Fe-WEHS (supply_Fe_WEHS), Fe citrate (supply_Fe_CITRATE) and Fe-PS (supply_Fe_PS). Tomato plants were hydroponically grown in all three case of Fe supply. Three different biological replicates were used for each sample repeating the experiment three times. All samples were obtained pooling roots of six plants (27-d-old).