Cuscuta campestris, a stem parasitic plant, has served as a valuable model plant for the exploration of plant-plant interactions and molecular trafficking. However, a major barrier to C. campestris research is that a method to generate stable transgenic plants has not yet been developed.
View Article and Find Full Text PDFWeeds in agricultural settings continually adapt to stresses from ecological and anthropogenic sources, in some cases leading to resistant populations. However, consequences of repeated sub-lethal exposure of these stressors on fitness and stress "memory" over generations remain poorly understood. We measured plant performance over a transgenerational experiment with Arabidopsis thaliana where plants were exposed to sub-lethal stress induced by the herbicides glyphosate or trifloxysulfuron, stresses from clipping or shading in either one (G1) or four successive generations (G1-G4), and control plants that never received stress.
View Article and Find Full Text PDFCrenate broomrape ( Forsk.) is a serious long-standing parasitic weed problem in Algeria, mainly affecting legumes but also vegetable crops. Unresolved questions for parasitic weeds revolve around the extent to which these plants undergo local adaptation, especially with respect to host specialization, which would be expected to be a strong selective factor for obligate parasitic plants.
View Article and Find Full Text PDFCuscuta campestris is an obligate parasitic plant that requires a host to complete its life cycle. Parasite-host connections occur via a 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.
View Article and Find Full Text PDFspp. are obligate parasites that connect to host vascular tissue using a haustorium. In addition to water, nutrients, and metabolites, a large number of mRNAs are bidirectionally exchanged between spp.
View Article and Find Full Text PDFWeeds, plants that thrive in the face of disturbance, have eluded human's attempts at control for >12 000 years, positioning them as a unique group of extreme stress tolerators. The most successful weeds have a suite of traits that enable them to rapidly adapt to environments typified by stress, growing in hostile conditions or subject to massive destruction from agricultural practices. Through their ability to persist and adapt, weeds illuminate principles of evolution and provide insights into weed management and crop improvement.
View Article and Find Full Text PDFNonphotosynthetic holoparasites exploit flexible targeting of phylloquinone biosynthesis to facilitate plasma membrane redox signaling. Phylloquinone is a lipophilic naphthoquinone found predominantly in chloroplasts and best known for its function in photosystem I electron transport and disulfide bridge formation of photosystem II subunits. Phylloquinone has also been detected in plasma membrane (PM) preparations of heterotrophic tissues with potential transmembrane redox function, but the molecular basis for this noncanonical pathway is unknown.
View Article and Find Full Text PDFThe genome of the parasitic plant Sapria himalayana reveals extraordinary changes that reflect its endoparasitic lifestyle. The genome has lost many genes, including the entire chloroplast genome, but has gained genes through horizontal gene transfer and repeated transposable elements.
View Article and Find Full Text PDFHorizontal gene transfer (HGT), the movement and genomic integration of DNA across species boundaries, is commonly associated with bacteria and other microorganisms, but functional HGT (fHGT) is increasingly being recognized in heterotrophic parasitic plants that obtain their nutrients and water from their host plants through direct haustorial feeding. Here, in the holoparasitic stem parasite Cuscuta, we identify 108 transcribed and probably functional HGT events in Cuscuta campestris and related species, plus 42 additional regions with host-derived transposon, pseudogene and non-coding sequences. Surprisingly, 18 Cuscuta fHGTs were acquired from the same gene families by independent HGT events in Orobanchaceae parasites, and the majority are highly expressed in the haustorial feeding structures in both lineages.
View Article and Find Full Text PDFParasitic plants steal sugars, water, and other nutrients from host plants through a haustorial connection. Several species of parasitic plants such as witchweeds ( spp.) and broomrapes ( and spp.
View Article and Find Full Text PDFParasitic weeds of the family Orobanchaceae attach to the roots of host plants via haustoria capable of drawing nutrients from host vascular tissue. The connection of the haustorium to the host marks a shift in parasite metabolism from autotrophy to at least partial heterotrophy, depending on the level of parasite dependence. Species within the family Orobanchaceae span the spectrum of host nutrient dependency, yet the diversity of parasitic plant metabolism remains poorly understood, particularly during the key metabolic shift surrounding haustorial attachment.
View Article and Find Full Text PDFDeoxyribonucleic acid (DNA) methylation is an epigenetic alteration crucial for regulating stress responses. Identifying large-scale DNA methylation at single nucleotide resolution is made possible by whole genome bisulfite sequencing. An essential task following the generation of bisulfite sequencing data is to detect differentially methylated cytosines (DMCs) among treatments.
View Article and Find Full Text PDFDodders (Cuscuta spp.) are obligate parasitic plants that obtain water and nutrients from the stems of host plants via specialized feeding structures called haustoria. Dodder haustoria facilitate bidirectional movement of viruses, proteins and mRNAs between host and parasite, but the functional effects of these movements are not known.
View Article and Find Full Text PDFContact with poison ivy plants is widely dreaded because they produce a natural product called urushiol that is responsible for allergenic contact delayed-dermatitis symptoms lasting for weeks. For this reason, the catchphrase most associated with poison ivy is "leaves of three, let it be", which serves the purpose of both identification and an appeal for avoidance. Ironically, despite this notoriety, there is a dearth of specific knowledge about nearly all other aspects of poison ivy physiology and ecology.
View Article and Find Full Text PDFThe parasitic plant Cuscuta exchanges mRNAs with its hosts. Systemic mobility of mRNAs within plants is well documented, and has gained increasing attention as studies using grafted plant systems have revealed new aspects of mobile mRNA regulation and function. But parasitic plants take this phenomenon to a new level by forming seamless connections to a wide range of host species, and raising questions about how mRNAs might function after transfer to a different species.
View Article and Find Full Text PDFHorizontal gene transfer (HGT) is the transfer of genetic material across species boundaries and has been a driving force in prokaryotic evolution. HGT involving eukaryotes appears to be much less frequent, and the functional implications of HGT in eukaryotes are poorly understood. We test the hypothesis that parasitic plants, because of their intimate feeding contacts with host plant tissues, are especially prone to horizontal gene acquisition.
View Article and Find Full Text PDFObligate parasitic plants in the Orobanchaceae germinate after sensing plant hormones, strigolactones, exuded from host roots. In Arabidopsis thaliana, the α/β-hydrolase D14 acts as a strigolactone receptor that controls shoot branching, whereas its ancestral paralog, KAI2, mediates karrikin-specific germination responses. We observed that KAI2, but not D14, is present at higher copy numbers in parasitic species than in nonparasitic relatives.
View Article and Find Full Text PDFCuscuta species (dodders) are parasitic plants that are able to grow on many different host plants and can be destructive to crops. The connections between Cuscuta and its hosts allow movement of not only water and small nutrients, but also macromolecules including mRNA, proteins and viruses. Recent studies show that RNAs move bidirectionally between hosts and parasites and involve a large number of different genes.
View Article and Find Full Text PDFThe origin of novel traits is recognized as an important process underlying many major evolutionary radiations. We studied the genetic basis for the evolution of haustoria, the novel feeding organs of parasitic flowering plants, using comparative transcriptome sequencing in three species of Orobanchaceae. Around 180 genes are upregulated during haustorial development following host attachment in at least two species, and these are enriched in proteases, cell wall modifying enzymes, and extracellular secretion proteins.
View Article and Find Full Text PDFMovement of RNAs between cells of a single plant is well documented, but cross-species RNA transfer is largely unexplored. Cuscuta pentagona (dodder) is a parasitic plant that forms symplastic connections with its hosts and takes up host messenger RNAs (mRNAs). We sequenced transcriptomes of Cuscuta growing on Arabidopsis and tomato hosts to characterize mRNA transfer between species and found that mRNAs move in high numbers and in a bidirectional manner.
View Article and Find Full Text PDFSeed germination of Striga spp. (witchweeds), one of the world's most destructive parasitic weeds, cannot be induced by light but is specifically induced by strigolactones. It is not known whether Striga uses the same components for strigolactone signaling as host plants, whether it has endogenous strigolactone biosynthesis and whether there is post-germination strigolactone signaling in Striga.
View Article and Find Full Text PDFA plant science research goal is to manipulate single cells in an intact organism in order to study their interactions with neighboring cells. Based on a technique previously demonstrated in isolated plant cells, mammalian cells and cyanobacteria, Arabidopsis epidermal cells were optoperforated to allow for uptake of external cascade blue-labeled dextrans. Adverse organelle responses were determined to be minimal and dye retention was demonstrated for at least 72 hours.
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