Project description:The purpose of this study was to annotate microRNAs in the parasitic plant Striga hermonthica and investigate any haustorial specific expression of novel microRNAs.
Project description:Complete sequence of the obligate, root hemi-parasitic plant Striga hermonthica. We sequenced an individual from an accession of S. hermonthica seeds collected from farmer’s fields in Kibos Kenya. An individual was selected at random from parasites growing on the highly susceptible rice cultivar NERICA 7 in a controlled environment experiment.
Project description:Using rice cultivars Nipponbare, which exhibits resistance to Striga hermonthica (a root parasitic plant that causes devastating loss of yield), and IAC165, which is susceptible, we aim to identify suites of genes underlying susceptibility and resistance to S. hermonthica by profiling changes in gene expression using rice whole genome microarrays. In addition to a functional categorisation of changes in gene expression, genes that were significantly differentially regulated within regions predicted to contain Nipponbare quantitative trait loci for resistance were identified. Keywords: Infected material vs. comparable control tissue, time course
Project description:Variation in strigolactone composition in sorghum root exudates underlies its resistance to parasitic weed, Striga hermonthica. Root exudates of the Striga susceptible variety Shanqui Red (SQR) contain primarily 5-deoxystrigol, which has a high efficiency of inducing Striga germination. SRN39 roots primarily exude orobanchol, leading to reduced Striga germination and making this variety resistant to Striga. This structural diversity in exuded strigolactones is determined by the polymorphism in the LGS1 (LOW GERMINATION STIMULANT 1) locus. Yet, the effects of the lgs1 mutation as well as the consequences of the vast genetic diversity between SQR and SRN39 have not been addressed in terms of growth and development. In response to this knowledge gap, we demonstrate additional consequences of LGS1 loss-of-function by phenotypic and molecular characterization. A suite of genes related to metabolism was differentially expressed between SQR and SRN39. Increased levels of gibberellin precursors in SRN39 were accompanied with its slower growth rate and developmental delay and we observed an overall increased SRN39 biomass. The slow-down in growth and differences in transcriptome profiles of SRN39 were strongly associated with plant age. Additionally, analyses of multiple LGS1 loss-of-function genotypes indicated that strigolactone stereochemistry influences root system architecture. To summarize, we demonstrated that the consequences of lgs1 mutation reach further than the changes in strigolactone profiles in root exudates and translates to alteration in growth and development.
