Identifying plant resistance pathways in Arabidopsis thaliana

Abstract only availableThe destruction of plants by a pathogen results in millions of dollars lost in crop yield annually. Identifying the plant response pathway to the presence of a pathogen is key to combating plant disease. The gene-for-gene hypothesis suggests that for every pathogen avirulence gene (avr), there is a corresponding specific plant resistance (R) gene that recognizes it and elicits a defense response. One method for discovering resistance pathways is through the use of a suppressor screen in which the deletion or mutation of a negative regulator can reactivate a signaling pathway. Our srfr (suppressor of rps4-RLD) mutants were discovered to provide resistance to the Pseudomonas syringae pv. tomato DC3000 expressing avrRps4 and thus is possibly a regulatory gene. The srfr mutants reactivated resistance to avrRps4 in plants that have a non-functional RPS4 gene. We are studying to see if the srfr gene signaling pathway reactivates avr responses dependent on R genes other than RPS4. We chose the well-studied RPM1 gene, which functions in detecting bacteria expressing avrRpm1. After crossing srfr3 and rpm1-3 mutants and harvesting F1 seeds, we grow these F1 seeds to get the F2 generation population. We isolated genomic DNA from F2 plants and then applied PCR based markers to find homozygous double mutants using 2 genetic markers linked to the srfr3 and rpm1-3 mutation, respectively. The F3 generation plants will be available to test disease symptoms in these double mutants. Based on the results of disease symptoms of the F3 population against bacteria expressing avrRpm1, we will propose whether or not the srfr3 gene is involved in the RPM1 defense signaling pathway. If the F3 generation is susceptible to avrRpm1, then srfr3 is not involved in the RPM1 defense signaling pathway.Plant Genomics Internship @ M

Properties of oriented strand board made from Betung bamboo (Dendrocalamus asper (Schultes.f) Backer ex Heyne)

Bamboo has gained increasing attention as an alternative raw material for use in the manufacture of composite boards. Three-layer OSBs were made using Betung bamboo (Dendrocalamus asper (Schultes.f) Backer ex Heyne) strands to evaluate the effects of strand length and pre-treatment techniques on the physical, mechanical, and durability properties. Three different strand lengths, namely 50, 60, and 70 mm, were prepared. Prior to the manufacture into OSB, the strands were immersed in cold water for 24 h and in 6% acetic anhydrides solution for 48 h. The OSBs were fabricated using 5% MDI resin based on the strand dry weight. The results indicated that MOR and MOE values in perpendicular to the grain direction were much influenced by strand length. The dimensional stability of OSB was slightly improved by immersing the strands in acetic anhydride solution. Immersing strands in cold water and acetic anhydride solution improved the resistance of OSB against subterranean termite (Macrotermes gylvus) attack under the adopted experimental condition. All OSB parameters manufactured in this experiment were better than the minimum requirement of CSA 0437.0 (Grade O–2) standard

Upper Eyelid Retraction After Periorbital Trauma

We report four unusual cases of upper eyelid retraction following periorbital trauma. Four previously healthy patients were evaluated for unilateral upper eyelid retraction following periorbital trauma. A 31-year-old man (Case 1) and a 24-year-old man (Case 2) presented with left upper eyelid retraction which developed after blow-out fractures, a 44-year-old woman (Case 3) presented with left upper eyelid retraction secondary to a periorbital contusion that occurred one week prior, and a 56-year-old man (Case 4) presented with left upper eyelid retraction that developed 1 month after a lower canalicular laceration was sustained during a traffic accident. The authors performed a thyroid function test and orbital computed tomography (CT) in all cases. Thyroid function was normal in all patients, CT showed an adhesion of the superior rectus muscle and superior oblique muscle in the first case and diffuse thickening of the superior rectus muscle and levator complex in the third case. CT showed no specific findings in the second or fourth cases. Upper eyelid retraction due to superior complex adhesion can be considered one of the complications of periorbital trauma

Full-length genomic analysis of korean porcine sapelovirus strains.

Porcine sapelovirus (PSV), a species of the genus Sapelovirus within the family Picornaviridae, is associated with diarrhea, pneumonia, severe neurological disorders, and reproductive failure in pigs. However, the structural features of the complete PSV genome remain largely unknown. To analyze the structural features of PSV genomes, the full-length nucleotide sequences of three Korean PSV strains were determined and analyzed using bioinformatic techniques in comparison with other known PSV strains. The Korean PSV genomes ranged from 7,542 to 7,566 nucleotides excluding the 3' poly(A) tail, and showed the typical picornavirus genome organization; 5'untranslated region (UTR)-L-VP4-VP2-VP3-VP1-2A-2B-2C-3A-3B-3C-3D-3'UTR. Three distinct cis-active RNA elements, the internal ribosome entry site (IRES) in the 5'UTR, a cis-replication element (CRE) in the 2C coding region and 3'UTR were identified and their structures were predicted. Interestingly, the structural features of the CRE and 3'UTR were different between PSV strains. The availability of these first complete genome sequences for PSV strains will facilitate future investigations of the molecular pathogenesis and evolutionary characteristics of PSV

Consecutive Macular Edema and Visual Outcome in Branch Retinal Vein Occlusion

Purposes. The study introduced the concept of “consecutive macular edema” and evaluated the validity of visual outcome in macular edema (ME) secondary to branch retinal vein occlusion (BRVO). Methods. Patients were categorized into the gainer group and the nongainer group according to the final visual acuity. We analyzed clinical characteristics involving total and consecutive duration of ME between the two groups. Results. Among the total 71 eyes of 71 patients, intravitreal bevacizumab injection (26 patients), triamcinolone (21), and natural course (33) were enrolled. The consecutive duration of ME was shorter in the gainer group than in the nongainer group (3.33 ± 1.50 and 5.24 ± 2.39 months; P=0.000). After exclusion of macular ischemia, consecutive duration of ME in gainer group was also significantly shorter than in nongainer group (3.62 ± 1.60 and 6.11 ± 4.20 months; P=0.010). Conclusions. The duration of ME in the nongainer group was longer than in the gainer group. In particular, the consecutive duration was an important factor in determining the final visual outcome. Clinical Trial Registration. Approval by Hallym University Sacred Heart Hospital Institutional Review Board/Ethics Committee was obtained for this retrospective study

Impact of Toxocariasis in Patients with Unexplained Patchy Pulmonary Infiltrate in Korea

Toxocariasis is one of the causes of pulmonary eosinophilic infiltrate that is increasing in Korea. This study was designed to identify the prevalence of toxocara seropositivity in patients with unexplained pulmonary patchy infiltrate and to evaluate associated factors. We evaluated 102 patients with unexplained pulmonary patchy infiltrate on chest computed tomography (CT) scan. As a control set, 116 subjects with normal chest CT were also evaluated. History of allergic disease, drug use, parasitic disease and raw cow liver intake were taken. Blood eosinophil count and total IgE level were measured. Specific serum IgG antibody to Toxocara canis larval antigen and specific IgG antibodies to 4 other parasites were measured by enzyme-linked immunosorbent assay (ELISA). In the infiltrate group, 66.7% subjects were toxocara seropositive whereas 22.4% of the control group were seropositive (p<0.001). In the infiltrate group, patients with a history of eating raw cow liver (odds ratio [OR], 7.8) and patients with eosinophilia (OR, 5.2) had a higher incidence of toxocara seropositivity. Thirty-five percent of toxocara seropositive patients with infiltrate exhibited migrating infiltrate and 48% had decreased infiltrate on the follow-up CT. We recommend that toxocara ELISA should be performed in patients with unexplained pulmonary patchy infiltrate, and that the eating of raw cow liver should be actively discouraged