Project description:Rice blast is a recurrent fungal disease, and resistance to fungal infection is a complex trait. Therefore, a comprehensive examination of rice transcriptome and its variation during fungal infection is necessary to understand the complex gene regulatory networks. In this study, adopting Next-Generation Sequencing we profiled the transcriptomes and microRNAomes of rice varieties, one susceptible and the other resistant to M. oryzae, at multiple time points during the fungal infection.
Project description:Heterosis is an important biological phenomenon; however, the role of small RNA (sRNA) in heterosis of hybrid rice remains poorly described. Here, we performed sRNA profiling of F1 super-hybrid rice LYP9 and its parents using high-throughput sequencing technology, and identified 355 distinct mature microRNAs and trans-acting small interfering RNAs, 69 of which were differentially expressed sRNAs (DES) between the hybrid and the mid-parental value. Among these, 34 DES were predicted to target 176 transcripts, of which 112 encoded 94 transcription factors. Further analysis showed that 67.6% of DES expression levels were negatively correlated with their target mRNAs either in flag leaves or panicles. The target genes of DES were significantly enriched in some important biological processes, including the auxin signalling pathway, in which existed a regulatory network mediated by DES and their targets, closely associated with plant growth and development. Overall, 20.8% of DES and their target genes were significantly enriched in quantitative trait loci of small intervals related to important rice agronomic traits including growth vigour, grain yield, and plant architecture, suggesting that the interaction between sRNAs and their targets contributes to the heterotic phenotypes of hybrid rice. Our findings revealed that sRNAs might play important roles in hybrid vigour of super-hybrid rice by regulating their target genes, especially in controlling the auxin signalling pathway. The above finding provides a novel insight into the molecular mechanism of heterosis. We constructed six sRNA sequencing libraries and six mRNA sequencing libraries of flag leaves and panicles of the super-hybrid rice Liangyou-pei9 (LYP9) combination at the grain-filling stage. The above hybrid rice combination includes F1 hybrid LYP9 and its parental lines including the male-sterile line Peiai64s (PA64s) and the restorer line 93-11.
Project description:Rice blast is a recurrent fungal disease, and resistance to fungal infection is a complex trait. Therefore, a comprehensive examination of rice transcriptome and its variation during fungal infection is necessary to understand the complex gene regulatory networks. In this study, adopting Next-Generation Sequencing we profiled the transcriptomes and microRNAomes of rice varieties, one susceptible and the other resistant to M. oryzae, at multiple time points during the fungal infection.
Project description:Plants are naturally associated with diverse microbial communities, which play significant roles in plant performance, such as growth promotion or fending off pathogens. The roots of Alkanna tinctoria L. are rich in naphthoquinones, particularly the medicinally used chiral compounds alkannin, shikonin and their derivatives. Former studies already have shown that microorganisms may modulate plant metabolism. To further investigate the potential interaction between A. tinctoria and associated microorganisms we performed a greenhouse experiment, in which A. tinctoria plants were grown in the presence of three distinct soil microbiomes. At four defined plant developmental stages we made an in-depth assessment of bacterial and fungal root-associated microbiomes as well as all primary and secondary metabolites. Our results showed that the plant developmental stage was the most important driver influencing the plant metabolite content, revealing peak contents of alkannin/shikonin at the fruiting stage. In contrast, the soil microbiome had the biggest impact on the plant root microbiome. Correlation analyses performed on the measured metabolite content and the abundance of individual bacterial and fungal taxa suggested a dynamic, at times positive or negative relationship between root-associated microorganisms and root metabolism. In particular, the bacterial Allorhizobium-Neorhizobium-Pararhizobium-Rhizobium group and the fungal species Penicillium jensenii were found to be positively correlated with higher content of alkannins.
Project description:The rate, timing, and mode of species dispersal is recognized as a key driver of the structure and function of communities of macroorganisms, and may be one ecological process that determines the diversity of microbiomes. Many previous studies have quantified the modes and mechanisms of bacterial motility using monocultures of a few model bacterial species. But most microbes live in multispecies microbial communities, where direct interactions between microbes may inhibit or facilitate dispersal through a number of physical (e.g., hydrodynamic) and biological (e.g., chemotaxis) mechanisms, which remain largely unexplored. Using cheese rinds as a model microbiome, we demonstrate that physical networks created by filamentous fungi can impact the extent of small-scale bacterial dispersal and can shape the composition of microbiomes. From the cheese rind of Saint Nectaire, we serendipitously observed the bacterium Serratia proteamaculans actively spreads on networks formed by the fungus Mucor. By experimentally recreating these pairwise interactions in the lab, we show that Serratia spreads on actively growing and previously established fungal networks. The extent of symbiotic dispersal is dependent on the fungal network: diffuse and fast-growing Mucor networks provide the greatest dispersal facilitation of the Serratia species, while dense and slow-growing Penicillium networks provide limited dispersal facilitation. Fungal-mediated dispersal occurs in closely related Serratia species isolated from other environments, suggesting that this bacterial-fungal interaction is widespread in nature. Both RNA-seq and transposon mutagenesis point to specific molecular mechanisms that play key roles in this bacterial-fungal interaction, including chitin utilization and flagellin biosynthesis. By manipulating the presence and type of fungal networks in multispecies communities, we provide the first evidence that fungal networks shape the composition of bacterial communities, with Mucor networks shifting experimental bacterial communities to complete dominance by motile Proteobacteria. Collectively, our work demonstrates that these strong biophysical interactions between bacterial and fungi can have community-level consequences and may be operating in many other microbiomes.
Project description:Crop breeding for board-spectrum disease resistance is the most profitable strategy to control diseases. However, knowledge on genes and mechanism of board-spectrum resistance is very limited. We fund a rice mutant ebr1 (enhanced blight and blast resistance 1) showed broad-spectrum resistance to both bacterial Xanthomonas oryzae pv. oryzae and fungal Magnaporthe oryzae associated with spontaneous programmed cell death (PCD), autoimmunity activation and stunting. EBR1 is located at the chromosome centromere and encodes a previously unknown RING-type protein with E3 ubiquitin ligase activity. Extensive yeast two-hybrid screening identified one EIP (EBR1-interacting) protein, EIP1, which belongs to the BAG (Bcl-2 associated athanogene) family that have been associated with stress responses and modulation of cell death.cross kingdoms. We showed that EIP1 is a specially target of EBR1 and is a key player activating PCD and immunity including the salicylic acid and jasmonate defense pathways in rice. Its function is suppressed EBR1-mediated degradation through ubiquitination. EIP1-RNAi could restore the PCD and disease resistance phenotypes of ebr1, while EIP1 overexpression caused strong PCD and enhanced resistance to rice pathogens likely ebr1. Together, our study reveals a unique E3 ligase-BAD protein module that orchestrates autoimmunity and trade-off between defense and growth in rice.
Project description:Many of the world’s most devastating crop diseases are caused by fungal pathogens which elaborate specialized infection structures to invade plant tissue. Here we present a quantitative mass spectrometry-based phosphoproteomic analysis of infection-related development by the rice blast fungus Magnaporthe oryzae, which threatens global food security. We mapped 8,005 phosphosites on 2,062 fungal proteins, revealing major re-wiring of phosphorylation-based signaling cascades during fungal infection. Comparingme phosphosite conservation across 41 fungal species reveals phosphorylation signatures specifically associated with biotrophic and hemibiotrophic fungal infection. We then used parallel reaction monitoring to identify phosphoproteins directly regulated by the Pmk1 MAP kinase that controls plant infection by M. oryzae. We define 33 substrates of Pmk1 and show that Pmk1-dependent phosphorylation of a newly identified regulator, Vts1, is required for rice blast disease. Defining the phosphorylation landscape of infection therefore identifies potential therapeutic interventions for control of plant diseases.
Project description:To study a hybrid weakness of rice, we have employed microarray expression profiling as a discovery platform to identify genes increased or decreased their expression specifically in the hybrid. Expression profiles of ‘Nipponbare’, ‘Jamaica’, and F1 hybrid were analyzed with ‘Rice oligo microarray kit’ of Agilent Technologies.