Rust-proofing wheat for a changing climate     

Sukumar Chakraborty  Jo Luck  Grant Hollaway  Glenn Fitzgerald  Neil White 《Euphytica》2011,179(1):19-32

This paper offers projections of potential effects of climate change on rusts of wheat and how we should factor in a changing climate when planning for the future management of these diseases. Even though the rusts of wheat have been extensively studied internationally, there is a paucity of information on the likely effects of a changing climate on the rusts and their influence on wheat production. Due to the lack of published empirical research we relied on the few published studies of other plant diseases, our own unpublished work and relevant information from the vast literature on rusts of wheat to prepare this overview. Three broad areas of potential risks from a changing climate were described: increased loss from wheat rusts, new rust pathotypes evolving faster and the reduced effectiveness of rust resistances. Increased biomass of wheat crops grown in the presence of elevated CO₂ concentrations and higher temperatures will increase the leaf area available for attack by the pathogen leading to increased inoculum production. If changed weather conditions were to accelerate the life cycle of a pathogen, the increased inoculum can lead to severe rust epidemics in many environments. Likewise should the effects of climate change result in more conducive conditions for rust development there will also be a corresponding increase in the rate of evolution of new pathotypes which could increase the rate of appearance of new virulences. The effectiveness of some rust resistance genes is influenced by temperature and crop development stage. Climate change may directly or indirectly influence the effectiveness of some resistance genes but this can not be ascertained due to a complete lack of knowledge. Since disease resistance breeding is a long term strategy it is important to determine if any of the important genes may become less effective due to climate change. Studies must be made to acquire new information on the rust disease triangle to increase the adaptive capacity of wheat under climate change. Leadership within the Borlaug Global Rust Initiative (BGRI) is needed to broker research on rust evolution and the durability of resistance under climate change.  相似文献   

Side-on copper-nitrosyl coordination by nitrite reductase     

Tocheva EI  Rosell FI  Mauk AG  Murphy ME 《Science (New York, N.Y.)》2004,304(5672):867-870

A copper-nitrosyl intermediate forms during the catalytic cycle of nitrite reductase, the enzyme that mediates the committed step in bacterial denitrification. The crystal structure of a type 2 copper-nitrosyl complex of nitrite reductase reveals an unprecedented side-on binding mode in which the nitrogen and oxygen atoms are nearly equidistant from the copper cofactor. Comparison of this structure with a refined nitrite-bound crystal structure explains how coordination can change between copper-oxygen and copper-nitrogen during catalysis. The side-on copper-nitrosyl in nitrite reductase expands the possibilities for nitric oxide interactions in copper proteins such as superoxide dismutase and prions.  相似文献   

Whither or wither microbicides?     

Grant RM  Hamer D  Hope T  Johnston R  Lange J  Lederman MM  Lieberman J  Miller CJ  Moore JP  Mosier DE  Richman DD  Schooley RT  Springer MS  Veazey RS  Wainberg MA 《Science (New York, N.Y.)》2008,321(5888):532-534

After disappointing results from all efficacy trials conducted to date, the field of microbicides research now faces substantial challenges. Poor coordination among interested parties and the choice of nonvalidated scientific targets for phase III studies have hampered progress and created mistrust about the use of microbicides as a method to prevent HIV-1 sexual transmission. Although new promising strategies are available, there will need to be serious reappraisals of how decisions are made to advance the next generations of candidates into clinical trials, and the use of appropriate animal models in this process will be critical.  相似文献   

Possible tornado-like tracks on Mars     

Grant JA  Schultz PH 《Science (New York, N.Y.)》1987,237(4817):883-885

Distinct atmospheric conditions suggest that dark, ephemeral, filamentary lineations on the martian surface may be formed during the passage of intense atmospheric vortices.  相似文献   

Surficial deposits at Gusev Crater along Spirit Rover traverses     

Grant JA  Arvidson R  Bell JF  Cabrol NA  Carr MH  Christensen P  Crumpler L  Des Marais DJ  Ehlmann BL  Farmer J  Golombek M  Grant FD  Greeley R  Herkenhoff K  Li R  McSween HY  Ming DW  Moersch J  Rice JW  Ruff S  Richter L  Squyres S  Sullivan R  Weitz C 《Science (New York, N.Y.)》2004,305(5685):807-810

The Mars Exploration Rover Spirit has traversed a fairly flat, rock-strewn terrain whose surface is shaped primarily by impact events, although some of the landscape has been altered by eolian processes. Impacts ejected basaltic rocks that probably were part of locally formed lava flows from at least 10 meters depth. Some rocks have been textured and/or partially buried by windblown sediments less than 2 millimeters in diameter that concentrate within shallow, partially filled, circular impact depressions referred to as hollows. The terrain traversed during the 90-sol (martian solar day) nominal mission shows no evidence for an ancient lake in Gusev crater.  相似文献   

Morphological correlates of differences in pheromone sensitivity in insect sensilla     

O'connell RJ  Grant AJ  Mayer MS  Mankin RW 《Science (New York, N.Y.)》1983,220(4604):1408-1410

Scanning electron microscopy and single unit recordings of male Trichoplusia ni antennae reveal at least two classes of pheromone-sensitive sensilla trichodea. The longer sensillum contains two receptor neurons each with small amounts of spontaneous activity. One neuron responds to large (10-microgram) doses of (Z)-7-dodecenyl acetate, a component of the female sex pheromone. The shorter sensillum contains two receptor neurons both with larger amounts of spontaneous activity and increased sensitivity to low (0.01-microgram) doses of pheromone.  相似文献   

Fossil Genes: Scarce as Hen's Teeth?     

Grant B  Wiseman LL 《Science (New York, N.Y.)》1982,215(4533):699-699

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Ecological character displacement     

Grant PR 《Science (New York, N.Y.)》1994,266(5186):746-747

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Temporal variability of the Atlantic meridional overturning circulation at 26.5 degrees N   总被引：4，自引：0，他引：4  

Cunningham SA  Kanzow T  Rayner D  Baringer MO  Johns WE  Marotzke J  Longworth HR  Grant EM  Hirschi JJ  Beal LM  Meinen CS  Bryden HL 《Science (New York, N.Y.)》2007,317(5840):935-938

The vigor of Atlantic meridional overturning circulation (MOC) is thought to be vulnerable to global warming, but its short-term temporal variability is unknown so changes inferred from sparse observations on the decadal time scale of recent climate change are uncertain. We combine continuous measurements of the MOC (beginning in 2004) using the purposefully designed transatlantic Rapid Climate Change array of moored instruments deployed along 26.5 degrees N, with time series of Gulf Stream transport and surface-layer Ekman transport to quantify its intra-annual variability. The year-long average overturning is 18.7 +/- 5.6 sverdrups (Sv) (range: 4.0 to 34.9 Sv, where 1 Sv = a flow of ocean water of 10(6) cubic meters per second). Interannual changes in the overturning can be monitored with a resolution of 1.5 Sv.  相似文献   

Amphibian orientation: an unexpected observation     

Twitty V  Grant D  Anderson O 《Science (New York, N.Y.)》1967,155(3760):352-353

The study of homing movements of displaced newts (Taricha rivularis) revealed unexpected features of the migratory behavior of amphibians. Newts leaving the breeding stream in the spring move not directly uphill but at an angle carrying them upstream. When they emerge after summer estivation this tendency is not evident in captures made during the autumn and winter. During the latter period, however, newly metamorphosed frogs (Rana boylii) show the same pronounced upstream migration that characterizes T. rivularis in the spring.  相似文献