Project description:Arabidopsis is a non-host to the biotrophic fungus Blumeria graminis f.sp. hordei (Bgh), effectively hindering Bgh ingress to the epidermal cells by deposition of callosic papillae formations, i.e. penetration resistance. To better understand the transcriptional changes in Arabidopsis towards Bgh, we compared un-inoculated and inoculated wild-type Arabidopsis samples, with those an ATAF1 mutant allele, compromised in penetration resistance. The experiment included sampling of 8 rosettes for each replicate sample from 6-weeks old plants, 12 hrs after inoculation. A total of 12 biolocigal replicates were sampled with three replicates from each of the four blocks (Wild-type, ataf1-1, Bgh, control). ****[PLEXdb(http://www.plexdb.org) has submitted this series at GEO on behalf of the original contributor, Michael Krogh Jensen. The equivalent experiment is AT31 at PLEXdb.] Experiment Overall Design: genotype: Wild-type Arabidopsis, ecotype Col-0 - treated or untreated: Un-inoculated(3-replications); genotype: Wild-type Arabidopsis, ecotype Col-0 - treated or untreated: Bgh inoculated(3-replications); genotype: ataf1-1 mutant, ecotype Col-0 - treated or untreated: Un-inoculated(3-replications); genotype: ataf1-1 mutant, ecotype Col-0 - treated or untreated: Bgh inoculated(3-replications)
Project description:Arabidopsis is a non-host to the biotrophic fungus Blumeria graminis f.sp. hordei (Bgh), effectively hindering Bgh ingress to the epidermal cells by deposition of callosic papillae formations, i.e. penetration resistance. To better understand the transcriptional changes in Arabidopsis towards Bgh, we compared un-inoculated and inoculated wild-type Arabidopsis samples, with those an ATAF1 mutant allele, compromised in penetration resistance. The experiment included sampling of 8 rosettes for each replicate sample from 6-weeks old plants, 12 hrs after inoculation. A total of 12 biolocigal replicates were sampled with three replicates from each of the four blocks (Wild-type, ataf1-1, Bgh, control). ****[PLEXdb(http://www.plexdb.org) has submitted this series at GEO on behalf of the original contributor, Michael Krogh Jensen. The equivalent experiment is AT31 at PLEXdb.]
Project description:RNA-seq experiments detected fungal expression patterns during infection of immunocompromised Arabidopsis thaliana 3 biological replicates per condition. Arabidopsis plants without (pps) or with (B12) the MLA1-HA construct in pen2 pad4 sag101 background were challenged with either Bgh isolate K1 expressing the cognate AVRA1 effector for MLA1 or Bgh isolate A6 expressing other AVRA effectors. Samples were collected at 6, 12, 18, 24 hours post inoculation (hpi) of Bgh.
Project description:A split-split-plot design with 144 experimental units (3 replications x 4 genotypes x 6 time points x 2 treatment types) was used to profile barley plants containing variants of Mla1 and Mla6 powdery mildew resistance genes in response to inoculation with the Blumeria graminis f. sp. hordei (Bgh) isolates 5874 (AvrMla1, AvrMla6). Barley leaves were harvested from inoculated and non-inoculated plants at 6 time points (0,8,16,20,24 and 32 hrs) after Bgh inoculation. ****[PLEXdb(http://www.plexdb.org) has submitted this series at GEO on behalf of the original contributor, Rico Caldo. The equivalent experiment is BB10 at PLEXdb.]
Project description:Using a transgenic line expressing HA-tagged ATAF1 uncovered >400 ChIP-seq peaks in ATAF1-HA plants compared to Col-0 wild-type plants. Only a small sub-set of the candidate peaks could be verified using ChIP-qpcr or EMSA. Among the verified peaks we uncovered the key ABA biosynthetic gene NCED3 as a target of ATAF1
Project description:Time-course expression profiles of Bgh challenged barley cultivar C.I. 16151 (harboring the Mla6 powdery mildew resistance allele) and its fast-neutron-derived "Bgh-induced tip cell death1" mutant, bcd1, were compared using the 22K Barley1 GeneChip. Planting, stage of seedlings, harvesting, and experimental design were part of a larger experiment described by Caldo et al. (2004). PLEXdb BB4. Experiment Design: C.I. 16151 (wildtype) and bcd1 (mutant) were planted in separate 20 x 30-cm flats using sterilized potting soil. Each experimental flat consisted of six rows of 15 seedlings, with rows randomly assigned to one of six harvest time points (0, 8, 16, 20, 24, and 32 hai). Seedlings grown to the 1st leaf stage with 2nd leaf unfolded were inoculated with a high density of fresh conidiospores (84 +/- 19 spores/mm2). Groups of flats were placed at 18C (8-hour darkness, 16-hour light) in separate controlled growth chambers corresponding to the Bgh isolates. Rows of plants were harvested at each assigned time points and snap frozen in liquid nitrogen. The entire experiment was repeated three times in a standard split-split-plot design with 72 experimental units (2 genotypes x 2 pathogen isolates x 6 time points x 3 replications). Treatment Description: The samples constituted pairwise combinations of the the cultivar C.I. 16151(containing the Mla6 resistance allele), and its fast-neutron-derived "Bgh-induced tip cell death1" mutant, bcd1 with the two Bgh (Blumeria graminis f. sp. hordei) isolates, 5874 (AvrMla6, AvrMla1) and K1 (AvrMla13, AvrMla1). For each replication, individual genotypes were planted in separate 20 x 30 cm flats using sterilized potting soil. Each experimental flat consisted of six rows of 15 seedlings, with rows randomly assigned to one of six harvest times (0, 8, 16, 20, 24, and 32 hai). Seedlings were grown to the 2nd-leaf stage with 1st leaf unfolded, and inoculation was performed at 4 PM Central Standard Time by tipping the flats at 45oC and dusting the plants with a high density of fresh conidiospores [84 +/- 19 spores/mm2]. This procedure was repeated from the opposite angle to ensure that a high proportion of the cells are in contact with the fungus. This conidial density per unit leaf area routinely results in greater than 50% of epidermal cells that are successfully infected. Groups of flats were placed at 18oC (8 hours darkness, 16 hours light, 8 hours darkness) in separate controlled growth chambers corresponding to the Bgh isolate. Rows of plants were harvested at their assigned harvest times and flash-frozen in liquid nitrogen. ****[PLEXdb(http://www.plexdb.org) has submitted this series at GEO on behalf of the original contributor, Roger P Wise. The equivalent experiment is BB46 at PLEXdb.]
Project description:We report that an intracellular NLR immune receptor from monocotyledonous barley is fully functional in dicotyledonous Arabidopsis thaliana. In contrast to common belief in plant NLR biology, this implies ~150 million years of evolutionary conservation of the underlying immune mechanism. This also suggests a conserved translocation mechanism for pathogen effectors in flowering plants. The deduced connectivity of the NLR to bifurcated signaling pathways likely confers increased robustness against pathogen interception, which could have contributed to the evolutionary preservation of the immune mechanism. RNA-seq experiments in Arabidopsis detected sustained expression of a single major MLA1-dependent gene cluster. 3 biological replicates per condition. The Arabidopsis plants without (pps) or with (B12) the MLA1-HA construct in a pen2 pad4 sag101 background were challenged with either the Bgh isolate K1 expressing the cognate AVRA1 effector for MLA1 or the Bgh isolate A6 expressing other AVRA effectors. Samples were collected at 6, 12, 18, 24 hours post inoculation (hpi) of Bgh.
Project description:Attack by the host powdery mildew Erysiphe cichoracearum usually results in successful penetration and rapid proliferation of the fungus on Arabidopsis. By contrast, the nonhost barley powdery mildew Blumeria graminis f. sp. hordei (Bgh) typically fails to penetrate Arabidopsis epidermal cells. In both instances the plant secretes cell wall appositions or papillae beneath the penetration peg of the fungus. Genetic screens for mutations that result in increased penetration of Bgh on Arabidopsis have recently identified the PEN1 syntaxin. Here we examine the role of PEN1 and of its closest homologue, SYP122, identified as a syntaxin whose expression is responsive to infection. pen1 syp122 double mutants are both dwarfed and necrotic, suggesting that the two syntaxins have overlapping functions. Although syp122-1 and the cell wall mur mutants have considerably more pronounced primary cell wall defects than pen1 mutants, these have relatively subtle or no effects on penetration resistance. Upon fungal attack, PEN1 appears to be actively recruited to papillae, and there is a 2-h delay in papillae formation in the pen1-1 mutant. We conclude that SYP122 may have a general function in secretion, including a role in cell wall deposition. By contrast, PEN1 appears to have a basal function in secretion and a specialized defense-related function, being required for the polarized secretion events that give rise to papilla formation.
Project description:Colonization of barley roots with the basidiomycete fungus Piriformospora indica enhances resistance against the leaf pathogen Blumeria graminis f.sp. hordei (Bgh). To identify genes involved in this mycorrhiza-induced systemic resistance, we used the Affymetrix Barley1 22K gene chip for leaf transcriptome analysis of P. indica-colonized and non-colonized barley plants 12, 24 and 96 hours post inoculation (hpi) with a compatible Bgh strain.
Project description:Using a transgenic line expressing HA-tagged ATAF1 uncovered >400 ChIP-seq peaks in ATAF1-HA plants compared to Col-0 wild-type plants. Only a small sub-set of the candidate peaks could be verified using ChIP-qpcr or EMSA. Among the verified peaks we uncovered the key ABA biosynthetic gene NCED3 as a target of ATAF1 ChIP was performed using anti-HA antibodies on wild-type Col-0 plants and plants expressing HA-tagged ATAF1