Project description:Drought is one of the most severe stresses leading to retardation of plant growth and development and loss of crop yield. Here we examined the proteome changes of an important oil seed crop canola Brassica napus under drought stress over a 14 day period. Using iTRAQ LC-MS/MS, we identified 2,244 proteins expressed during drought stress. Among them, 412 proteins showed significant changes in abundance under stress, and 67, 243, 287, and 79 proteins were differentially expressed in 3rd, 7th, 10th, and 14th day of drought stress, respectively. Functional analysis of the 412 proteins indicated that the number of proteins associated with “Metabolism”, “Protein synthesis”, and “Signaling” decreased, while those related to “Photosynthesis” and “Stress and defense” increased in response to drought stress. In particular, the proteome profiles at the 7th and 10th day were similar to each other, although there were much more post-translational modifications (PTM) at the 10th day of drought. Interestingly, 286 of 2,244 proteins exhibited PTMs in response to drought stress, 82 of which were differentially changed in drought-stressed plants, and 60 were observed at the 10th day. Furthermore, comparison of protein expression changes with those of gene transcription showed that there was positive correlation in B. napus, although there were different patterns between transcripts and proteins at each time point. As drought stress prolongs, most of the protein abundance changes may be attributed to gene transcription, and PTMs clearly contribute to the protein diversity and functions.
Project description:Canola (oilseed rape, Brassica napus L.), is susceptible to infection by the biotrophic protist Plasmodiophora brassicae, the causal agent of clubroot. To understand the roles of microRNAs (miRNAs) during the post-transcriptional regulation of disease initiation and progression, we have characterized the changes in miRNA expression profiles in canola roots during clubroot disease development and have compared these to uninfected roots. Two different stages of clubroot development were targeted in this miRNA profiling study: an early time of 10-dpi for disease initiation and a later 20-dpi, by which time the pathogen had colonized the roots (as evident by visible gall formation and histological observations). P. brassicae responsive miRNAs were identified and validated by qRT-PCR of miRNAs and the subsequent validation of the target mRNAs through starBase degradome analysis, and through 5’ RLM-RACE. This study identifies putative miRNA-regulated genes with roles during clubroot disease initiation and development. Putative target genes identified in this study included: transcription factors (TFs), hormone-related genes, as well as genes associated with plant stress response regulation such as cytokinin, auxin/ethylene response elements. The results of our study may assist in elucidating the role of miRNAs in post-transcriptional regulation of target genes during disease development and may contribute to the development of strategies to engineer durable resistance to this important phytopathogen.
Project description:The fullerenes, a kind of carbon nanoparticles, have potential for enhanced stress tolerance in plants. While the positive effects of polyhydroxy fullerene—fullerol on plants in response to drought at the physiological level have been documented, the molecular mechanism in Brassica napus are not entirely understood. In this study, exogenous fullerol was applied to the leaves of B. napus seedlings given drought. The leaves of B. napus seedlings in each treatment (sufficient water condition, drought, and drought combined with fullerol) were used to conduct the molecular mechanism using transcriptomic analysis.
Project description:Clubroot of Brassicaceae, an economically important soil borne disease, is caused by Plasmodiophora brassicae Woronin, an obligate, biotrophic protist. This disease poses a serious threat to canola and related crops in Canada and around the globe causing significant loss to seed yield. The pathogen is continuously evolving and new pathotypes are emerging, this necessitates the development of novel resistant canola cultivars to manage the disease effectively. Given that proteins play a crucial role in majority of biological processes and molecular functions, the identification of differentially abundant proteins (DAP) using proteomics information is an attractive approach to understand the plant-pathogen interactions as well as in the future development of gene specific markers for developing clubroot resistant (CR) cultivars. In this study, P. brassicae pathotype 3 (P3H) was used to challenge CR and clubroot susceptible (CS) canola lines. Root samples were collected at three distinct stages of pathogenesis, 7-, 14-, and 21-days post inoculation (DPI), protein samples were isolated, digested with trypsin and subjected to LC-MS/MS analysis. A total of 937 proteins demonstrated a significant (q < 0.05) change in abundance in at least in one of the time points when compared between control and inoculated CR-parent, CR-progeny, CS-parent, CS-progeny and 784 proteins were significantly (q < 0.05) changed in abundance in at least in one of the time points when compared between the inoculated- CR and CS root proteomes of parent and progeny across the three time points tested. Functional annotation of the differentially abundant proteins (DAPs) revealed several proteins related to calcium dependent signaling pathways in response to the pathogen. In addition, proteins related to reactive oxygen species (ROS) biochemistry, dehydrins, lignin, thaumatin, and phytohormones were identified. Among the DAPs, 74 putative proteins orthologous to CR proteins and quantitative trait loci (QTL) associated with eight CR loci in four chromosomes including chromosomes A3 and A8 were identified. In conclusion, these results have contributed to an improved understanding of the mechanisms that are involved in mediating response to P. brassicae in canola at the protein level.
Project description:Canola (oilseed rape, Brassica napus L.), is susceptible to infection by the biotrophic protist Plasmodiophora brassicae, the causal agent of clubroot. To understand the roles of microRNAs (miRNAs) during the post-transcriptional regulation of disease initiation and progression, we have characterized the changes in miRNA expression profiles in canola roots during clubroot disease development and have compared these to uninfected roots. Two different stages of clubroot development were targeted in this miRNA profiling study: an early time of 10-dpi for disease initiation and a later 20-dpi, by which time the pathogen had colonized the roots (as evident by visible gall formation and histological observations). P. brassicae responsive miRNAs were identified and validated by qRT-PCR of miRNAs and the subsequent validation of the target mRNAs through starBase degradome analysis, and through 5M-bM-^@M-^Y RLM-RACE. This study identifies putative miRNA-regulated genes with roles during clubroot disease initiation and development. Putative target genes identified in this study included: transcription factors (TFs), hormone-related genes, as well as genes associated with plant stress response regulation such as cytokinin, auxin/ethylene response elements. The results of our study may assist in elucidating the role of miRNAs in post-transcriptional regulation of target genes during disease development and may contribute to the development of strategies to engineer durable resistance to this important phytopathogen. In this miRNA-microarray experiment a total of 4 samples were analyzed with their 3 biological replicates. In which 2 samples C 10 DAY and C 20 DAY was used as referrence contols.
Project description:Cultivation of canola at temperatures above the optimum growth temperature of 21°C for prolonged periods, especially during the flowering stage, resulted in several adverse effects, including rapid vegetative growth, reduced viability of female gametophytes, increased seed abortion rate, accelerated embryo development, and a reduction in seed oil composition (Young et al., 2004; Mácová et al., 2022; Secchi et al., 2023). One of the distinctive phenotypes observed during the seed development of certain canola cultivars subjected to prolonged heat stress affecting the seed yield is the occurrence of the pre-harvest sprouting phenotype (PHS) (Mácová et al., 2022). Misregulation of seed dormancy by abscisic acid and dormancy-related genes is thought to be the primary cause of PHS in many cereal crops (Benech-Arnold & Rodríguez, 2018; Tai et al., 2021). This phenotype is associated with seed coat rupture (SCR), observed in seeds during the early stages of maturation. In this study, we employed a multi-methodological approach to investigate the occurrence of SCR phenotype in seeds of Brassica napus cv. Topas. The results demonstrate that SCR occurs in seeds around 20 days after pollination (20DAP) when the plants are cultivated in elevated temperatures over an extended period. The unrestricted embryonic growth exerts pressure on the seed coat, as evidenced by a reduction in the thickness of the seed coat cell layers. This results in an early alteration to the cell wall composition, with an increased proportion of demethylesterified pectin, which is likely to stiffen the seed coat, thereby rendering it more susceptible to rupture. The precise mechanism by which accelerated embryo development influences heat stress-mediated seed development in canola plants has yet to be elucidated.
Project description:Selection for improved energy efficiency and drought tolerance in canola results in distinct transcriptome and epigenome changes [ChIP-Seq]