Project description:The hemibiotrophic fungal pathogen Leptosphaeria maculans is the causal agent of blackleg disease in Brassica napus (canola, oilseed rape) and causes significant losses in crop yields worldwide. While genetic resistance has been used to mitigate the disease, little information about the genes and gene regulatory networks underlying blackleg resistance is currently available. High-throughput RNA sequencing and rigorous bioinformatics approaches revealed dynamic changes in the host transcriptome and identified plant defense pathways specific to the host-pathogen incompatible LepR1-AvrLepR1 interaction.
Project description:Global insights into high temperature and drought stress regulated genes by RNA-Seq in economically important oilseed crop Brassica juncea
Project description:In species with exalbuminous seeds such as crucifer oilseeds and legumes, the endosperm is eventually consumed and its space occupied by the embryo during seed development. However, the main constituent of the early developing seed is the liquid endosperm, and most of the carbon resources for the ensuing stages of seed development arrive at the embryo through the endosperm. In contrast to the extensive study of species with persistent endosperm, little is known about the global gene expression pattern in the endosperm of exalbuminous seed species. We took a multiparallel approach that combines ESTs, protein profiling and microarray analyses to look into the gene expression landscape in the endosperm of the oilseed crop Brassica napus. An EST collection of over 30,000 entries allowed us to detect close to 10,000 unisequences expressed in the endosperm. A protein profile analysis of more than 800 proteins corroborated several signature pathways uncovered by abundant ESTs. Using microarray analyses, we identified genes that are differentially or highly expressed across all developmental stages. These complementary analyses provided insight on several prominent metabolic pathways in the endosperm. We also discovered that LEC1 was highly expressed in the endosperm and that the regulatory cascade downstream of LEC1 operates in the endosperm. The endosperm EST collection and the microarray dataset provide a basic genomic resource for dissecting metabolic and developmental events important for oilseed improvement. Our findings on the featured metabolic processes and the LEC1 regulatory cascade offer new angles for investigation on the integration of endosperm gene expression with embryo development and storage product deposition in seed development. Keywords: seed development
Project description:MicroRNAs are multifunctional non-coding short nucleotide molecules. Nevertheless, the role of miRNAs in the interactions between plants and necrotrophic pathogens is largely unknown. Here, we report the identification of the miRNA repertoire of the economically important oil crop oilseed rape (Brassica napus) and those involved in interacting with its most devastating necrotrophic pathogen Sclerotinia sclerotiorum. We identified 280 B. napus miRNA candidates, including 53 novel candidates and 227 canonical members or variants of known miRNA families, by high-throughput deep sequencing of small RNAs from both normal and S. sclerotiorum-inoculated leaves. Target genes of 15 novel candidates and 222 known miRNAs were further identified by sequencing of degradomes from the two types of samples. MicroRNA microarray analysis revealed that 68 miRNAs were differentially expressed between S. sclerotiorum-inoculated and uninoculated leaves. A set of these miRNAs target genes involved in plant defense to S. sclerotiorum and/or other pathogens such as NBS-LRR R genes and nitric oxygen and reactive oxygen species related genes. Additionally, three miRNAs target AGO1 and AGO2, key components of post-transcriptional gene silencing (PTGS). Expression of several viral PTGS suppressors reduced resistance to S. sclerotiorum. Arabidopsis mutants of AGO1 and AGO2 exhibited reduced resistance while transgenic lines over-expressing AGO1 displayed increased resistance to S. sclerotiorum in an AGO1 expression level-dependent manner. Moreover, transient over-expression of miRNAs targeting AGO1 and AGO2 decreased resistance to S. sclerotiorum in oilseed rape. Our results demonstrate that the interactions between B. napus and S. sclerotiorum are tightly regulated at miRNA level and probably involve PTGS.
Project description:MicroRNAs are multifunctional non-coding short nucleotide molecules. Nevertheless, the role of miRNAs in the interactions between plants and necrotrophic pathogens is largely unknown. Here, we report the identification of the miRNA repertoire of the economically important oil crop oilseed rape (Brassica napus) and those involved in interacting with its most devastating necrotrophic pathogen Sclerotinia sclerotiorum. We identified 280 B. napus miRNA candidates, including 53 novel candidates and 227 canonical members or variants of known miRNA families, by high-throughput deep sequencing of small RNAs from both normal and S. sclerotiorum-inoculated leaves. Target genes of 15 novel candidates and 222 known miRNAs were further identified by sequencing of degradomes from the two types of samples. MicroRNA microarray analysis revealed that 68 miRNAs were differentially expressed between S. sclerotiorum-inoculated and uninoculated leaves. A set of these miRNAs target genes involved in plant defense to S. sclerotiorum and/or other pathogens such as NBS-LRR R genes and nitric oxygen and reactive oxygen species related genes. Additionally, three miRNAs target AGO1 and AGO2, key components of post-transcriptional gene silencing (PTGS). Expression of several viral PTGS suppressors reduced resistance to S. sclerotiorum. Arabidopsis mutants of AGO1 and AGO2 exhibited reduced resistance while transgenic lines over-expressing AGO1 displayed increased resistance to S. sclerotiorum in an AGO1 expression level-dependent manner. Moreover, transient over-expression of miRNAs targeting AGO1 and AGO2 decreased resistance to S. sclerotiorum in oilseed rape. Our results demonstrate that the interactions between B. napus and S. sclerotiorum are tightly regulated at miRNA level and probably involve PTGS.
Project description:B. napus, a widely cultivated oilseed crop spanning roughly 35 million hectares world-wide (Faostat , 2022), faces various stress factors including salt stress which reduces plant height, size, and yield (Shahza d et al., 2022; Naheed et al., 2021). Endophytic microorganisms are known to promote plant growth and biomass production (Rho et al., 2018, Azad et al., 2016, Zhang et al., 2019). In this study, inoculation with endophyte Acremonium alternatum increased both fresh and dry weight under salt stress conditions. Further molecular analyses provided insights into potential mechanisms involved, highlighting a putative role of abscisic acid in mediating ROS metabolism and ion sequestering. These findings contribute to our understanding of plant-fungi interactions and offer promising leads for developing novel biological agents to improve crop production under the challenges posed by climate change.
Project description:The purpose of the present study is to determine the effect of Phosphorus deficiency on gene expression level using microarray analysis to identify genes responsible for root hair development. Phosphorus deficiency induced the formation of root hairs to explore a greater soil volume but molecular mechanisms were unknown. Therefore, microarray experiments were performed using root tips of Brassica carinata cultivars Bale and Bacho, respectively differing in root hair length during Phosphorus deficiency. Experimental design was carried out in nutrient solution in a climate chamber with controlled environmental conditions (20°C, 16h day/8h night cycle, 70% relative humidity) in a randomized design. 25 root tips from 10 day old seedlings grown without Phosphorus of 1cm length were harvested and immediately frozen in liquid nitrogen. Gene expression analyses were performed
Project description:UV-B radiation regulates numerous morphogenic, biochemical and physiological responses in plants, and can stimulate some responses typically associated with other abiotic and biotic stimuli, including invertebrate herbivory. Removal of UV-B from the growing environment of various plant species has been found to increase their susceptibility to consumption by invertebrate pests, however, to date, little research has been conducted to investigate the effects of UV-B on crop susceptibility to field pests. Here, we report findings from a multi-omic and genetic-based study investigating the mechanisms of UV-B-stimulated resistance of the crop, Brassica napus (oilseed rape), to herbivory from an economically important lepidopteran specialist of the Brassicaceae, Plutella xylostella (diamondback moth). The UV-B photoreceptor, UV RESISTANCE LOCUS 8 (UVR8), was not found to mediate resistance to this pest. RNA-Seq and untargeted metabolomics identified components of the sinapate/lignin biosynthetic pathway that were similarly regulated by UV-B and herbivory. Arabidopsis mutants in genes encoding two enzymes in the sinapate/lignin biosynthetic pathway, CAFFEATE O-METHYLTRANSFERASE 1 (COMT1) and ELICITOR-ACTIVATED GENE 3-2 (ELI3-2), retained UV-B-mediated resistance to P. xylostella herbivory. However, overexpression of B. napus COMT1 in Arabidopsis further reduced plant susceptibility to P. xylostella herbivory in a UV-B-dependent manner. These findings demonstrate that overexpression of a component of the sinapate/lignin biosynthetic pathway in a member of the Brassicaceae can enhance UV-B-stimulated resistance to herbivory from P. xylostella.