Independently evolved virulence effectors converge onto hubs in a plant immune system network

Plants generate effective responses to infection by recognizing both conserved and variable pathogen-encoded molecules. Pathogens deploy virulence effector proteins into host cells, where they interact physically with host proteins to modulate defense. We generated an interaction network of plant-pathogen effectors from two pathogens spanning the eukaryote-eubacteria divergence, three classes of Arabidopsis immune system proteins, and ~8000 other Arabidopsis proteins. We noted convergence of effectors onto highly interconnected host proteins and indirect, rather than direct, connections between effectors and plant immune receptors. We demonstrated plant immune system functions for 15 of 17 tested host proteins that interact with effectors from both pathogens. Thus, pathogens from different kingdoms deploy independently evolved virulence proteins that interact with a limited set of highly connected cellular hubs to facilitate their diverse life-cycle strategies.     

Enhanced CpG mutability and tumorigenesis in MBD4-deficient mice

The mammalian protein MBD4 contains a methyl-CpG binding domain and can enzymatically remove thymine (T) or uracil (U) from a mismatched CpG site in vitro. These properties suggest that MBD4 might function in vivo to minimize the mutability of 5-methylcytosine by removing its deamination product from DNA. We tested this hypothesis by analyzing Mbd4-/- mice and found that the frequency of of C --> T transitions at CpG sites was increased by a factor of three. On a cancer-susceptible Apc(Min/+) background, Mbd4-/- mice showed accelerated tumor formation with CpG --> TpG mutations in the Apc gene. Thus MBD4 suppresses CpG mutability and tumorigenesis in vivo.     

Genome sequence of Aedes aegypti, a major arbovirus vector

We present a draft sequence of the genome of Aedes aegypti, the primary vector for yellow fever and dengue fever, which at approximately 1376 million base pairs is about 5 times the size of the genome of the malaria vector Anopheles gambiae. Nearly 50% of the Ae. aegypti genome consists of transposable elements. These contribute to a factor of approximately 4 to 6 increase in average gene length and in sizes of intergenic regions relative to An. gambiae and Drosophila melanogaster. Nonetheless, chromosomal synteny is generally maintained among all three insects, although conservation of orthologous gene order is higher (by a factor of approximately 2) between the mosquito species than between either of them and the fruit fly. An increase in genes encoding odorant binding, cytochrome P450, and cuticle domains relative to An. gambiae suggests that members of these protein families underpin some of the biological differences between the two mosquito species.     

The status of the world's land and marine mammals: diversity, threat, and knowledge

Knowledge of mammalian diversity is still surprisingly disparate, both regionally and taxonomically. Here, we present a comprehensive assessment of the conservation status and distribution of the world's mammals. Data, compiled by 1700+ experts, cover all 5487 species, including marine mammals. Global macroecological patterns are very different for land and marine species but suggest common mechanisms driving diversity and endemism across systems. Compared with land species, threat levels are higher among marine mammals, driven by different processes (accidental mortality and pollution, rather than habitat loss), and are spatially distinct (peaking in northern oceans, rather than in Southeast Asia). Marine mammals are also disproportionately poorly known. These data are made freely available to support further scientific developments and conservation action.     

Nordonna: A red-skinned potato cultivar with wide adaptability

NorDonna is a mid-season, red-skinned, white-fleshed cultivar that yields a large percentage of U.S. No. 1 tubers in diverse growing areas under both dryland and irrigated conditions. It tends to have a darker red skin and a lower incidence of hollow heart when compared to other red cultivars. Intended for tablestock use, NorDonna has baking, boiling, and microwaving properties comparable to Red Pontiac or Red Norland. The North Dakota Agricultural Experiment Station released NorDonna on April 28, 1995.     

Anti-phytopathogenic activities of macro-algae extracts

Aqueous and ethanolic extracts obtained from nine Chilean marine macro-algae collected at different seasons were examined in vitro and in vivo for properties that reduce the growth of plant pathogens or decrease the injury severity of plant foliar tissues following pathogen infection. Particular crude aqueous or organic extracts showed effects on the growth of pathogenic bacteria whereas others displayed important effects against pathogenic fungi or viruses, either by inhibiting fungal mycelia growth or by reducing the disease symptoms in leaves caused by pathogen challenge. Organic extracts obtained from the brown-alga Lessonia trabeculata inhibited bacterial growth and reduced both the number and size of the necrotic lesion in tomato leaves following infection with Botrytis cinerea. Aqueous and ethanolic extracts from the red-alga Gracillaria chilensis prevent the growth of Phytophthora cinnamomi, showing a response which depends on doses and collecting-time. Similarly, aqueous and ethanolic extracts from the brown-alga Durvillaea antarctica were able to diminish the damage caused by tobacco mosaic virus (TMV) in tobacco leaves, and the aqueous procedure is, in addition, more effective and seasonally independent. These results suggest that macro-algae contain compounds with different chemical properties which could be considered for controlling specific plant pathogens.     

Transgenic cereals: Current status and future prospects

This review summarises the history of transgenic (GM) cereals, principally maize, and then focuses on the scientific literature published in the last two years. It describes the production of GM cereals with modified traits, divided into input traits and output traits. The first category includes herbicide tolerance and insect resistance, and resistance to abiotic and biotic stresses; the second includes altered grains for starch, protein or nutrient quality, the use of cereals for the production of high value medical or other products, and the generation of plants with improved efficiency of biofuel production. Using data from field trial and patent databases the review considers the diversity of GM lines being tested for possible future development. It also summarises the dichotomy of response to GM products in various countries, describes the basis for the varied public acceptability of such products, and assesses the development of novel breeding techniques in the light of current GM regulatory procedures.     

Health-promoting effects of a dietary fiber concentrate from the soybean byproduct okara in rats

Okara (a byproduct of the soy milk industry) is rich in proteins (24.5-37.5 g/100 g of dry matter (dm)), lipids (9.3-22.3 g/100 g of dm), and dietary fiber (DF) (14.5-55.4 g/100 g of dm). It also contains isoflavones (0.14 g/100 g of dm). In the present study we fed female healthy Wistar rats either a standard rat diet or a supplemented 10% DF-rich okara (DFRO) diet for 4 weeks, and then we assessed several health parameters in the serum and the cecum compartments. In comparison to the control group, rats fed DFRO showed a significant decrease in weight gain (5.00 +/- 1.22 g vs 2.00 +/- 1.46 g, P < 0.03, during week 4) and in total cholesterol (65 +/- 8 mg/dL vs 51 +/- 5 mg/dL, P < 0.05) and a significantly increased antioxidant status (36.71 +/- 15.31 micromol of Trolox equivalents (TEs)/g vs 69.75 +/- 16.11 micromol of TEs/g, P < 0.0003) and butyrogenic effect (39.37%, P < 0.003) in the cecum. In addition, a significant enhancement in the apparent absorption (41.89 +/- 1.64% vs 47.02 +/- 2.51%, P < 0.004) and in the true retention (41.62 +/- 1.60% vs 46.68 +/- 2.55%, P < 0.005) of calcium was appreciated. In summary, these findings show for the first time that a concentrate DF from a soybean byproduct protects the gut environment in terms of antioxidant status and prebiotic effect. These results may highlight the development of an innovative soybean byproduct rich in DF which could be useful as a functional ingredient with health-promoting attributes.     

Effect of variety and maturation of cheese on supercritical fluid extraction efficiency

Supercritical fluid extraction (SFE) has been utilized by the food industry in many applications to extract, fractionate, and recover compounds from various food matrices. However, little research has been conducted using SFE as an alternative process for producing reduced-fat cheese. Lipids in cheeses may be selectively extracted due to the nonpolar properties of supercritical carbon dioxide (SC-CO2), without leaving residual chemicals as is the case in solvent extraction. The objective of this study was to evaluate the influence on the extraction process due to cheese variety and protein breakdown by age. A Latin square design was utilized to test the extractability of lipids from Parmesan and Cheddar cheeses, aged young (9-10 months) or old (24 months). Extraction took place in a 500 mL SFE vessel using 100 g of grated cheese samples. The SFE parameters of the extraction were 350 bar, 35 degrees C, and supercritical carbon dioxide at a flow rate of 20 g/min for 55 min. Compositional analysis measured all treated samples and controls of total lipids, lipid profiling, total protein, protein/peptide analysis, moisture, ash, and pH. Cheese type was a major variable in fat extraction. The extraction in Cheddar showed an average fat reduction of 53.56% for young cheese, whereas that in old Cheddar was 47.90%. However, young Parmesan was reduced an average of 55.07%, but old Parmesan was reduced at 68.11%, measured on a dry basis. SFE extracted triglycerides and cholesterol, but did not remove phospholipids. This investigation introduces the observations of the effect of Cheddar and Parmesan varieties on SFE, offering data on the important parameters to consider in the design of SFE processes to reduce fat in cheese.     

Assessment of fungal communities in soil and tomato roots subjected to diverse land and crop management systems

Effects of diverse agricultural land management practices on soil and on root colonizing fungal communities were determined through a PCR-based molecular method and a culture-dependent method, respectively, in a field location with uniform soil type. Initiated in July 2000, the management systems were: conventional tomato production, frequent tillage (disk fallow), undisturbed weed fallow, bahiagrass pasture (Paspalum notatum var. notatum ‘Argentine’), and an organically managed system including cover crops and annual applications of poultry manure and urban plant debris. Culture-dependent colony counting was used to identify and enumerate communities of root colonizing fungi and length heterogeneity polymerase chain reaction (LH-PCR) analysis of internal transcribed spacer-1 (ITS-1) profiles to characterize phylotypes in soil fungal communities. Three years after initiation of land management treatments and midway through tomato cultivation, both methods detected a high degree of similarity in fungal community composition between weed fallow and bahiagrass plots. Soil fungal communities in organically managed plots were similar to each other and distinct from communities in other land management systems while the composition of root colonizing fungal communities in organic plots was divergent. The results demonstrate that the soil fungal communities and root colonizing fungal communities were affected differently depending on land and crop management practices. Fusarium oxysporum was a dominant species in all soil and root colonizing fungal communities except those subjected to organic management practices.