Project description:Transcriptional profiling of three mexican maize landraces under 10, and 17 days stress and recovery irrigation A dye balanced modified loop design was implemented. Two biological replicates (pooling five representative plants) representing each sampling point for each genotype were obtained for purified RNA from 120 randomly chosen seedlings. This experiment involved a total of forty-eight (24 sets) of microarray hybridizations, including direct and dye swap comparisons between treatments as well as across the three landraces. This design allowed us to determine differences in gene expression between the three different landraces under drought stress (10 and 17 days) and at recovery irrigation compared to irrigated controls.
Project description:Locally adapted maize accessions (landraces) represent an untapped resource of nutritional and resistance traits for breeding, including the shaping of distinct microbiota. Our study focused on five different maize landraces and a reference commercial hybrid, showing different susceptibility to fusarium ear rot, and whether this trait could be related to particular compositions of the bacterial microbiota in the embryo, using different approaches. Our cultivation-independent approach utilized the metabarcoding of a portion of the 16S rRNA gene to study bacterial populations in these samples. Multivariate statistical analyses indicated that the microbiota of the embryos of the accessions grouped in two different clusters: one comprising three landraces and the hybrid, one including the remaining two landraces, which showed a lower susceptibility to fusarium ear rot in field. The main discriminant between these clusters was the frequency of Firmicutes, higher in the second cluster, and this abundance was confirmed by quantification through digital PCR. The cultivation-dependent approach allowed the isolation of 70 bacterial strains, mostly Firmicutes. In vivo assays allowed the identification of five candidate biocontrol strains against fusarium ear rot. Our data revealed novel insights into the role of the maize embryo microbiota and set the stage for further studies aimed at integrating this knowledge into plant breeding programs.
Project description:The fungal pathogen Fusarium moniliforme causes ear rot in maize. Ear rot in maize is a destructive disease globally caused by Fusarium moniliforme , due to decrease of grain yield and increase of risks in raising livestock by mycotoxins production. Plants have developed various defense pathways to cope with pathogens. We used microarrays to detail the global programme of gene expression during the infection process of Fusarium moniliforme in its host plant to get insights into the defense programs and the host processes potentially involved in plant defense against this pathogen.
Project description:The fungal pathogen Fusarium moniliforme causes ear rot in maize. Ear rot in maize is a destructive disease globally caused by Fusarium moniliforme , due to decrease of grain yield and increase of risks in raising livestock by mycotoxins production. Plants have developed various defense pathways to cope with pathogens. We used microarrays to detail the global programme of gene expression during the infection process of Fusarium moniliforme in its host plant to get insights into the defense programs and the host processes potentially involved in plant defense against this pathogen. Experiment Overall Design: In two compared independent experiments plants were infected with the Fusarium moniliforme. Samples from infected bracts of resistant maize (Bt-1) as well as susceptible maize (Ye478) were taken at 4 days post infection. Samples from uninfected control plants were taken at the same time points. For example: R0 (control) and RT (treat) in Bt-1 and S0 (control) and ST (treat) in Ye478.
Project description:There is a need for expansion of the available potato genomic and transcriptomic resources in order to explore novel traits for potato improvement. Transcriptomic data derived from leaves from eleven native South American potato landraces (ten Peruvian and another; TBR Chilean) has been collected in order to aid the annotation of these genomes.
Project description:Background: Sorghum bicolor is a remarkably drought tolerant cereal crop. Its natural biodiversity that enables this tolerance has developed in sub-Saharan Africa. The sequencing of the sorghum genome in 2009 has expedited research of this crop which has also been proposed as a model C4 cereal crop for genomics. In this study, the genetic response mechanisms involved in sorghums’ tolerance to progressive water deficit and moderate re-watering were investigated in three previously uncharacterized South African landraces (designated: LR5, LR6 and LR35) using cDNA microarrays comprising 35 899 transcript probes. Results: Across the three landraces, significant differential expression of 1 797 genes, including 264 genes with currently unknown functions, were altered in response to progressive water stress and re-watering. The modulated sorghum genes had homology to proteins involved in growth, regulation, and protection. Gene ontology analysis identified significant enrichment of 26 genes involved in the ‘response to abiotic stimulus’ GO category in LR6 during severe stress. The expression of USP responded to progressive water stress and moderate re-watering in LR6 and LR35. Moreover, our results indicate a putative role for β-alanine betaine biosynthesis in drought tolerance of sorghum. Conclusions: This study identified the drought responsive gene complement of three previously uncharacterized South African sorghum landraces. Each landrace is a distinct genotype and similar responses to water deficit and re-watering were not expected. Functional characterizations of some of the differentially expressed genes found in this study may be used as possible targets for marker-assisted breeding or transgenic initiatives for sorghum and, other closely related crop species.
Project description:Fusarium verticillioides is a detrimental fungus that can contaminate maize grains with mycotoxins that are harmful to human and animal health. Breeding and growing resistant genotypes is one alternative to reduce contamination and subsequent production of mycotoxins by this fungus. However, little is known about the resistant mechanism relevant to breeding in this pathosystem. Therefore, our aim was to identify genes and metabolites that may be related to Fusarium ear rot resistance using resistant and susceptible maize inbreds. Kernels of the resistant inbred showed significantly reduced disease severity, and reduced levels of total fumonisin and ergosterol content compared with the susceptible one. Gene expression data were obtained from microarray hybridizations using F. verticillioides inoculated and non inoculated maize kernels. Differentially expressed sequences were identified and classified into 36 functional categories. Most of the differentially expressed genes were assigned to the categories “protein, RNA, DNA, stress, transport, signaling and cell metabolism”. These genes encode for PR proteins, detoxification and primary metabolism enzymes. Fungal inoculation did not produce considerable changes in gene expression and metabolites in the resistant L4637 inbred, probably due to a preformed or constitutive resistance mechanism. Defense-related genes were induced or repressed in kernels of the susceptible inbred L4674, responding specifically to the pathogen infection. The qRT-PCR in infected silks showed that glucanase, lipid transfer, xylanase inhibitor, PR1 and 26S proteosome transcripts had higher expression ratios in the susceptible line compared to the resistant one in response to fungal infection. Through this study, a global view of differential genes expressed and metabolites concentration during resistance and susceptibility to F. verticillioides inoculation has been obtained, giving additional information about the mechanisms and pathways conferring resistance to this important disease in maize. Global view of differential genes expressed during resistance and susceptibility to F. verticillioides inoculation. Two maize inbred lines : one resistant (L4637) and one susceptible (L4674) to F. verticillioides infection. Two-condition experiment, Inoculated (I) vs. non-inoculated (NI) lines. Biological replicates: 3 . One replicate per array.