Project description:Germination of seeds of Orobanche species requires specific chemicals exuded by host roots. A family of “divergent” KARRIKIN INSENSITIVE2 (KAI2d) genes encode proteins that recognize strigolactone (SL) class germination simulants. We explored specificity of germination stimulant detection by analyzing interspecific segregants of a cross between Orobanche cernua and O. cumana, closely related species that differ in stimulant response. O. cernua parasitizes tomato and germinates in response to the SL orobanchol, while O. cumana parasitizes sunflower and responds to dehydrocostus lactone (DCL). KAI2d genes were catalogued in parents and in segregants that showed stimulant specificity. KAI2d genes were also functionally assayed in the Arabidopsis kai2 mutant background. We identified five full-length KAI2d genes in O. cernua and eight in O. cumana. The O. cernua KAI2d2, as well as its ortholog in O. cumana, are associated with SL perception. A cluster of O. cumana KAI2d genes was genetically linked to DCL perception, although no specific receptor gene was identified by heterologous complementation. These findings support the KAI2d-mediated perception of SLs, but fall short of explaining how O. cumana perceives DCL. The ability of some O. cumana KAI2d genes to detect SLs points to the involvement of additional factors in regulating stimulant specificity.
2022-02-20 | GSE196954 | GEO
Project description:Biological and transcriptomic characterization of resistance to sunflower broomrape (Orobanche cumana W.) in sunflower (Helianthus annuus L.)
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:Helianthus annuus and Orobanche cumana Raw sequence reads
Project description:As the most studied type of epigenetic modifications found in many taxa, DNA methylation has been confirmed to play a crucial role in transposon silencing, transcriptional regulation and thus phenotypic variation, as well as rapid adaption to changing environments. To fully understand the methylome variation in Trichinella, here, we report 12 single-base resolution methylomes of three life stages using WGBS. By comparative epigenomics, we observe that the methylome variation in Trichinella is significantly divergent and host-related. By comparative epigenomics, we observe that the methylome variation in Trichinella is significantly divergent and host-related. By comparing DNA methylation patterns between different host classes of species, we found a fraction of parasitism-related genes under epigenetic regulation, such as G-protein-coupled receptor, DNaseII and ligand-gated chloride channel. Moreover, we also reveal associations between methylation divergence and genetic basis, including nucleotide variant and structural variation.
2021-06-01 | GSE139486 | GEO
Project description:Host PBGD confers resistance in malaria parasite
Project description:The objective of this study was to evaluate the role of cytochrome P450 monooxygenases (P450s) and other detoxification-related proteins in Imisun sunflower resistance. Two sunflower inbred lines were used: HA 425 and HA 89, imidazolinone (IMI)-resistant and susceptible, respectively. Growth response to imazethapyr herbicide in combination with P450s inhibitors 1-aminobenzotriazole (ABT) and piperonyl butoxide (PBO) was evaluated in 15-day-old sunflower plantlets. Roots were collected and label-free quantitation (LFQ) proteomic analysis were carried out in order to characterize plant response to IMI. Roots of 15-day-old plants treated with 0 and 3.3 µM imazethapyr were frozen in liquid nitrogen. Protein extraction was performed as described in Wu et al. (2014) from 1 g root tissue per genotype/treatment combination.
Project description:<p>Sunflower pollen is a natural nutritious food with a long history and multiple functions, however, the main chemical components apart from flavonoids and their biosynthesis processes have not been thoroughly investigated. In this study, seven hydroxycinnamic acid amides (HCAAs) (1-7) abundant in sunflower pollen were isolated and identified as one type of the pollen's main chemicals. For a comprehensive understanding of HCAA biosynthesis in <em>Helianthus annuus</em> flowers, RNA-seq, metabolomics, and key genes related to biosynthesis in the sunflower were studied. A large number of compounds at different sunflower growth stages (the 7th, 14th, 21st and 28th days) and high expression levels of related genes in the transcriptome were detected. A molecular network was constructed to clarify the synthetic pathway of HCAAs, which revealed high transcriptional levels of spermidine hydroxycinnamoyl transferase genes (<em>HaSHT2795</em> and <em>HaSHT2436</em>) in 14-21 day-old flowers. <em>HaSHT2795</em> enzymes catalyze tri-coumaroylspermidine formation, and virus-induced gene silencing to inhibit <em>HaSHT2795</em> and <em>HaSHT2436</em> could significantly reduce the synthesis of hydroxycinnamic acid amides in sunflower pollen. HCAAs were inferred to be related to the formation of pollen walls and the health effects of pollen. Analyzing HCAA biosynthesis and accumulation in <em>H. annuus</em> pollen will be helpful to understand the functions of HCAAs in the development of pollen and its nutritional value.</p>