Arbuscular mycorrhizal fungi enhanced cadmium uptake in Photinia frase through altering root transcriptomes and root-associated microbial communities / 生物工程学报

As a non-essential metal, cadmium (Cd) pollution poses severe threats to plant growth, environment, and human health. Phytoextraction using nursery stocks prior to their transplantation is a potential useful approach for bioremediation of Cd contaminated soil. A greenhouse pot experiment was performed to investigate the growth, Cd accumulation, profiles of transcriptome as well as root-associated microbiomes of Photinia frase in Cd-added soil, upon inoculation of two types of arbuscular mycorrhizal fungi (AMF) Sieverdingia tortuosa and Funneliformis mosseae. Compared with the control, inoculation of F. mosseae increased Cd concentrations in root, stem and leaf by 57.2%, 44.1% and 71.1%, respectively, contributing to a total Cd content of 182 μg/plant. KEGG pathway analysis revealed that hundreds of genes involved in 'Mitogen-activated protein kinase (MAPK) signaling pathway', 'plant hormone signal transduction', 'biosynthesis of secondary metabolites' and 'glycolysis/gluconeogenesis' were enriched upon inoculation of F. mosseae. The relative abundance of Acidobacteria was increased upon inoculation of S. tortuosa, while Chloroflexi and Patescibacteria were increased upon inoculation of F. mosseae, and the abundance of Glomerales increased from 23.0% to above 70%. Correlation analysis indicated that ethylene-responsive transcription factor, alpha-aminoadipic semialdehyde synthase, isoamylase and agmatine deiminase related genes were negatively associated with the relative abundance of Glomerales operational taxonomic units (OTUs) upon inoculation of F. mosseae. In addition, plant cysteine oxidase, heat shock protein, cinnamoyl-CoA reductase and abscisic acid receptor related genes were positively associated with the relative abundance of Patescibacteria OTUs upon inoculation of F. mosseae. These finding suggested that AMF can enhance P. frase Cd uptake by modulating plant gene expression and altering the structure of the soil microbial community. This study provides a theoretical basis for better understanding the relationship between root-associated microbiomes and root transcriptomes of P. frase, from which a cost-effective and environment-friendly strategy for phytoextraction of Cd in Cd-polluted soil might be developed.

Identification and Characterization of Pseudocercospora pyricola Causing Leaf Spots on Aronia melanocarpa

Leaf spot disease on black chokeberry (Aronia melanocarpa) was observed at several locations in Korea during 2014–2015. Leaf spots were distinct, scattered over the leaf surface and along the leaf border, subcircular to irregular and brown surrounded by a distinct dark color, and were expanded and coalesced into irregularly shaped lesions. Severely infected leaves became dry and fell off eventually. The causative agent was identified as Pseudocercospora pyricola. Morphological observations and phylogenetic analyses of multiple genes, including internal transcribed spacer, translation elongation factor 1-alpha, actin, and the large subunit ribosomal DNA were conducted. The pathogenicity test was conducted twice yielding similar results, fulfilling Koch's postulates. To our knowledge, this is the first report on P. pyricola infection of A. melanocarpa globally.

First Report of Leaf Spot Caused by Alternaria tenuissima on Black Chokeberry (Aronia melanocarpa) in Korea

In July 2015, diseased leaves of black chokeberry (Aronia melanocarpa) were observed in Danyang and Gochang, Korea. The symptoms appeared as circular or irregular brown leaf spots, from which Alternaria tenuissima was isolated. The isolates were cultured on potato dextrose agar, and their morphological characteristics were observed under a light microscope. The colonies were whitish to ash colored. The pathogenicity test on healthy black chokeberry leaves produced circular brown spots, in line with the original symptoms. Molecular analyses of the ITS, GPD, RPB2, and TEF genes were conducted to confirm the identity of the pathogen. The phylogeny of the multi-gene sequences indicated that the causal agent was A. tenuissima. This study is the first report of A. tenuissima leaf spot on black chokeberry (A. melanocarpa).

The Preventive and Therapeutic Effects of Aronox Extract on Metabolic Abnormality and Hypertension

BACKGROUND: Aronox is an anthocyanin-rich extract from Aronia melanocarpa E which is known to have anti-inflammatory effect in atherosclerosis due to high anti-oxidative activity. This study was conducted to evaluate the preventive and therapeutic effect of Aronox on hypertension and metabolic status in spontaneously hypertensive rats (SHR). METHODS: Seven-week-old male SHR were orally administrated with Aronox (low dose; 100 mg/kg, n = 4 or high dose; 200 mg/kg, n = 3) or amlodipine (10 mg/kg, n = 7) and sham (n = 10) for 8 weeks. Aronox was administered 30 mg/kg for the first 3 weeks and then increased to 100 mg/kg (low dose group) or 100 mg/kg to 200 mg/kg (high dose group). Systolic blood pressure (SBP) was measured every week by tail cuff method. At 8 weeks, fasting lipid level was measured. Heart and kidney stained with Masson's trichrome. RESULTS: Aronox or amlodipine treatment showed significantly lower SBP compared with sham (202.2 +/- 10.2 mm Hg in low dose group, 202.0 +/- 12.6 mm Hg in high dose group and 187.4 +/- 22.7 mm Hg in amlodipine group vs. 224.4 +/- 12 mm Hg in sham-SHR, p < 0.005). There were no significant differences in cardiac and renal weight corrected by body weight among 3 groups. Aronox and amlodipine treatments significantly decreased fasting glucose and showed a trend of decrease in triglyceride level. Aronox or amlodipine treatment for 8 weeks showed less collagen deposition changes compared to sham. CONCLUSIONS: Aronox showed significant antihypertensive effects, decreased fasting glucose, and less cardiac and renal fibrosis in SHR. These results suggest that Aronox can be used as an adjuvant therapy or functional food in hypertension.