Project description:Little is known about plant pathogenic response to parasitic plants, although some parasitic plants affect crop production in certain areas. To study this, we chose Glycine max as the model host plant and investigated changes in expression patterns after parasitization by Cuscuta using microarrays. Transcriptional change of Glycine max stem with and without Cuscuta at 2 different stages were compared
Project description:Little is known about plant pathogenic response to parasitic plants, although some parasitic plants affect crop production in certain areas. To study this, we chose Glycine max as the model host plant and investigated changes in expression patterns after parasitization by Cuscuta using microarrays.
Project description:The parasitic plant Cuscuta campestris produces specialized microRNAs that are specifically expressed at the haustorial interface. Some of these "Interface-Induced MicroRNAs" function to target host mRNAs. C. campestris haustoria can be induced in the absence of any host tissues using a combination of light and physical pressure. This experiment tested with such in vitro, host-free haustoria produced interface-induced microRNAs. Small RNA-seq was performed from three different treatments: Shoot tips of C. campestris without any haustoria formation, in vitro haustoria formed in the presence of host tissue (detached leaves of Arabidopsis thaliana) and in vitro haustoria formed in the absence of any host tissue.
Project description:Parasitism is a successful life strategy that has evolved independently in several families of Higher Plants. In parasitic plants, nutrients and water are obtained from their hosts through specifically adapted haustoria. The genera Cuscuta and Orobanche represent examples for the two profoundly different groups of parasites, one parasitizing host shoots and the other infecting host roots. In this study, we sequenced and described the overall repertoire of small RNAs (sRNome) from Cuscuta campestris and compared it to an exploratory sRNome from Orobanche aegyptiaca. Because they regulate the genomic information by mechanisms like RNA interference, these sRNomes add important bricks to our understanding of the success of the parasitic lifestyle. We could show that Cuscuta campestris contains a number of novel microRNAs (miRNAs) in addition to a conspicuous retention of miRNAs that are typically lacking in other Solanales, while several typically conserved miRNAs seem to have become obsolete in the parasite. One new miRNA appears to be derived from a horizontal gene transfer event, a process never reported in plants for the acquisition of new miRNA sequences. The exploratory miRNome (exploratory due to the absence of a full genomic sequence for reference) from the root parasitic Orobanche aegyptiaca also revealed a loss of a number of miRNAs compared to established miRNomes of photosynthetic species from the same order. In summary, our study shows for both parasites partly similar evolutionary signatures in the RNA silencing machinery. Our data bear proof for the dynamism of this regulatory mechanism in parasitic plants.
2022-07-22 | GSE181576 | GEO
Project description:The genome of parasitic plant Cuscuta australis
Project description:Plant lodging severely reduced crop yield and quality. Different plant growth regulators (PGRs) have been applied to improve lodging resistance through the regulation of physiological changes, especially on the increase of stem thickness and strength. Melatonin is a pleiotropic PGR for the regulation of plant growth and development. In this study, we demonstrated that the exogenous treatment of melatonin to Glycine max significantly enhanced plant lateral growth by increasing stem diameter. In addition to the stem thickness, secondary cell wall (SCW) deposition acts as another critical factor for stem rigidity for lodging resistance. To understand whether exogenous treatment of melatonin would regulate SCW biosynthesis genes, we performed transcriptomic analyses on the stems of Glycine max with or without melatonin treatment. Through the differentially-expressed-genes (DEGs) analyses, many SCW biosynthesis genes were found to be regulated by melatonin, including the cellulose, hemicellulose and lignin biosynthesis enzymes. We also found that the two known master regulators, NAC and MYB, of SCW biosynthesis genes were induced under melatonin treatment, which further supported our observation on the differential expression of SCW biosynthesis genes. Our study highlighted the improvement of lodging resistance by the exogenous treatment of melatonin through the increase of plant stem thickness and the regulation of SCW biosynthesis genes and their upstream TFs in Glycine max.
Project description:Cuscuta campestris is an obligate parasitic plant that requires a host to complete its lifecycle. Parasite-host connections occur via an haustorium, a unique organ that acts as a bridge for the uptake of water, nutrients and macromolecules. Research on Cuscuta is often complicated by host influences, but comparable systems for growing the parasite in the absence of a host do not exist. We developed an axenic method to grow C. campestris on an Artificial Host System (AHS). We evaluated the effects of nutrients and phytohormones on parasite haustoria development and growth. Haustorium morphology and gene expression were characterized. The AHS consists of an inert, fibrous stick that mimics a host stem, wicking water and nutrients to the parasite. It enables C. campestris to exhibit a parasitic habit and develop through all stages of its lifecycle, including production of new shoots and viable seeds. Phytohormones NAA and BA affect haustoria morphology, and increase parasite fresh weight and biomass. Gene expression in AHS haustoria reflect process similar to those in haustoria on actual host plants. The AHS is a methodological improvement for studying Cuscuta biology by avoiding specific host effects on parasite and giving researchers full control of the parasite environment.