SP290-Z Frank A. Hale, Professor Darrell Hensley, Assistant Extension Specialist Entomology and Plant Pathology The Agricultural Extension Service receives numerous inquiries for information about where insect predators and parasitoids can be purchased. These insects are intended for use by both homeowners and commercial growers as biological control agents. Biological control uses benefi cial organisms rather than insecticides to reduce insect populations. Almost all insect groups include some benefi cial members. The use of benefi cial organisms is particularly important where chemical residues are undesirable. Benefi cial organisms can be predators, such as ladybugs, lacewings and praying mantids that feed on other insects. Others, such as some species of nematodes and wasps, including Trichogramma, are parasitoids with an immature stage that lives on or inside a host, which the parasitoid eventually kills. Trichogramma wasps lay their eggs into the eggs of caterpillars, where they develop by feeding inside the host’s egg. An example of a benefi cial pathogen is Bacillus thuringiensis, which is used as a microbial insecticide. The Tennessee Department of Agriculture does not list the decollate snail, Rumina decollata, as a biological control organism suitable to be brought into Tennessee. The Agricultural Extension Service is not in the business of advertising, selling or buying benefi cial organisms. This list of sources was compiled as a response to public requests for information. This listing and general description of benefi cial organisms are not recommendations and do not imply effectiveness in controlling any pest. Commercially Available Biological Control Agents 1 Aphidoletes aphidimyza: A predatory midge that feeds on aphids. 2 Anisopteromalus calandre: A wasp that is a parasitoid of weevil larvae in stored grain. 3 Aphelinus abdominalis: A parasitoid wasp of aphids. 4 Predatory ladybird beetles. 5 Bracon hebetor: A wasp that is a parasitoid of lepidopteran pests of stored grain such as the Indian meal moth and the Mediterranean fl our moth. 6 Bacillus thuringiensis: Microbial insecticide for control of lepidopteran pests (butterfl y and moth caterpillars). 7 Macrocentrus ancylivorus: Parasitoid wasp of oriental fruit moth. 8 Mealybug destroyer, Cryptolaemus montrouzieri: A predatory lady beetle that feeds on mealybugs. 9 Diadegma insulare: An ichneumonid parasitoid wasp of diamondback moth larvae. 10 Diaeretiella rapae: This wasp is a parasitoid of aphids such as the cabbage aphid and the green peach aphid. 11 Aphidius matricariae and/or Aphidius colemani and/or aphidius ervi: Parasitic wasps of aphids. 12 Eretmocerus eremicus: (=californicus): A parasitoid wasp of whitefl ies. 13 Fly parasites and predators: For fl y control in poultry manure, etc. 14 Greenhouse whitefl y parasitoid wasps (Encarsia sp). 15 Goniozus legneri and/or Pentalitomastix sp.: Navel orange worm parasitoids for almond and walnut crops. 16 Gnatrol or other brand names of Bacillus thuringiensis subsp. israelensis: Used as a soil drench for fungus gnat larvae in soil mixes. 17 Neoseiulus (=Amblyseius) cucumeris: A predatory mite of thrips. 18 Bacillus thuringiensis Berliner var. israelensis, Serotype H-14: For control of mosquitoes and black fl y, Mosquito Dunks, Vectobac or other brands. 19 Neoseiulus (=Amblyseius) barkeri (= mckenziei): A predatory mite of thrips. 20 Dacnusa sibirica and/or Diglyphus isaea: Parasitoid wasps of leafminers on tomatoes and other plants. 21 Predatory lacewings, Chrysoperla (= Chrysopa) spp. 22 Predatory mites. 23 Macrolophus caliginosus: A predatory mirid bug that feeds on whitefl Fungal Parasites and Pathogens Fungal Parasites and Pathogens Bởi: OpenStaxCollege Parasitism describes a symbiotic relationship in which one member of the association benefits at the expense of the other Both parasites and pathogens harm the host; however, the pathogen causes a disease, whereas the parasite usually does not Commensalism occurs when one member benefits without affecting the other Plant Parasites and Pathogens The production of sufficient good-quality crops is essential to human existence Plant diseases have ruined crops, bringing widespread famine Many plant pathogens are fungi that cause tissue decay and eventual death of the host ([link]) In addition to destroying plant tissue directly, some plant pathogens spoil crops by producing potent toxins Fungi are also responsible for food spoilage and the rotting of stored crops For example, the fungus Claviceps purpurea causes ergot, a disease of cereal crops (especially of rye) Although the fungus reduces the yield of cereals, the effects of the ergot's alkaloid toxins on humans and animals are of much greater significance In animals, the disease is referred to as ergotism The most common signs and symptoms are convulsions, hallucination, gangrene, and loss of milk in cattle The active ingredient of ergot is lysergic acid, which is a precursor of the drug LSD Smuts, rusts, and powdery or downy mildew are other examples of common fungal pathogens that affect crops 1/6 Fungal Parasites and Pathogens Some fungal pathogens include (a) green mold on grapefruit, (b) powdery mildew on a zinnia, (c) stem rust on a sheaf of barley, and (d) grey rot on grapes In wet conditions Botrytis cinerea, the fungus that causes grey rot, can destroy a grape crop However, controlled infection of grapes by Botrytis results in noble rot, a condition that produces strong and muchprized dessert wines (credit a: modification of work by Scott Bauer, USDA-ARS; credit b: modification of work by Stephen Ausmus, USDA-ARS; credit c: modification of work by David Marshall, USDA-ARS; credit d: modification of work by Joseph Smilanick, USDA-ARS) Aflatoxins are toxic, carcinogenic compounds released by fungi of the genus Aspergillus Periodically, harvests of nuts and grains are tainted by aflatoxins, leading to massive recall of produce This sometimes ruins producers and causes food shortages in developing countries Animal and Human Parasites and Pathogens Fungi can affect animals, including humans, in several ways A mycosis is a fungal disease that results from infection and direct damage Fungi attack animals directly by colonizing and destroying tissues Mycotoxicosis is the poisoning of humans (and other animals) by foods contaminated by fungal toxins (mycotoxins) Mycetismus describes the ingestion of preformed toxins in poisonous mushrooms In addition, individuals who display hypersensitivity to molds and spores develop strong and dangerous allergic reactions Fungal infections are generally very difficult to treat because, unlike bacteria, 2/6 Fungal Parasites and Pathogens fungi are eukaryotes Antibiotics only target prokaryotic cells, whereas compounds that kill fungi also harm the eukaryotic animal host Many fungal infections are superficial; that is, they occur on the animal’s skin Termed cutaneous (“skin”) mycoses, they can have devastating effects For example, the decline of the world’s frog population in recent years may be caused by the chytrid fungus Batrachochytrium dendrobatidis, which infects the skin of frogs and presumably interferes with gaseous exchange Similarly, more than a million bats in the United States have been killed by white-nose syndrome, which appears as a white ring around the mouth of the bat It is caused by the cold-loving fungus Geomyces destructans, which disseminates its deadly spores in caves where bats hibernate Mycologists are researching the transmission, mechanism, and control of G destructans to stop its spread Fungi that cause the superficial mycoses of the epidermis, hair, and nails rarely spread to the underlying tissue ([link]) These fungi are often misnamed “dermatophytes”, from the Greek words dermis meaning skin and phyte meaning plant, although they are not plants Dermatophytes are also called “ringworms” because of the red ring they cause on skin They secrete extracellular enzymes that break down keratin (a protein found in hair, skin, and nails), causing conditions such as athlete’s foot and jock itch These conditions are usually treated with over-the-counter topical creams and powders, and are easily cleared More persistent superficial mycoses may require prescription oral medications (a) Ringworm presents as a red ring on skin; (b) Trichophyton violaceum, shown in this bright field light micrograph, causes superficial mycoses on the scalp; (c) Histoplasma capsulatum is an ascomycete that infects airways and causes symptoms similar to influenza (credit a: modification of work by Dr Lucille K Georg, CDC; credit b: modification ...Ann. For. Sci. 63 (2006) 597–612 597 c INRA, EDP Sciences, 2006 DOI: 10.1051/forest:2006040 Review Interactive effects of drought and pathogens in forest trees Marie-Laure D-L a * , Benoit M ¸ b , Louis-Michel N c , Dominique P a , Andrea V d a INRA Bordeaux, UMR BIOGECO, Équipe de pathologie forestière, Domaine de la Grande Ferrade, BP81, 33883 Villenave d’Ornon Cedex, France b INRA Nancy, UMR IaM, Équipe de pathologie forestière, Champenoux, 54280 Seichamps, France c Ministère de l’Agriculture, de la Pêche, et des Affaires Rurales, Département Santé des Forêts, Champenoux, 54280 Seichamps, France d University of Tuscia, Department of Plant Protection, Via S. Camillo de Lellis, 01100 Viterbo, Italy (Received 14 October 2005; accepted 28 April 2006) Abstract – This review synthesizes the available knowledge on drought-disease interactions in forest trees with a focus on (1) evidence and patterns of drought-disease interactions, (2) current understanding of processes and mechanisms, and (3) three well documented cases studies. The first part is based on the analysis of a database of slightly more than one hundred studies, obtained by keyword searches combining drought, diseases or pathogens, and forest trees. A large majority of published studies referred to a positive association between drought and disease, i.e. disease favoured by drought or drought and disease acting synergistically on tree health status, with a predominance of canker/dieback diseases, caused by pathogens like Botryosphaeria, Sphaeropsis, Cytospora and Biscognauxia (Hypoxylon). The type of disease-related variables (incidence vs. severity) and the intensity and timing of water stress were shown to be significant factors affecting the drought- infection interaction. Interactions with other abiotic stresses and species-specific and genetic effects, related to host or pathogen, have also been reported. Direct effects of drought on pathogens are generally negative, although most fungal pathogens exhibit an important plasticity and can grow at water potentials well below the minimum for growth of their host plants. Studies on indirect effects of drought on pathogens through other community interactions are still relatively scarce. Positive drought-infection effects can mostly be explained by indirect effects of drought on host physiology. The predisposition and the multiple stress hypotheses are presented, as well as recent developments in the study of the molecular basis of abiotic and biotic stress, and their interactions. Sphaeropsis sapinea on pines, Biscognauxia mediterranea on oaks and root pathogens in declines associated with drought provide illustrative examples, treated as case studies, of pathogens of current significance associated with drought. The conclusion highlights some knowledge gaps, e.g. the role of latent parasites and the shift to a pathogenic stage, or the genetics of some fungal groups. The need for prevention of pathogen dispersal, especially crucial in the case of latent pathogens, is emphasized. drought / water stress / pathogenic fungi / predisposition / forest trees Résumé – Interactions entre sécheresse et agents pathogènes chez les arbres forestiers. Cette revue synthétise les connaissances actuelles sur les interactions entre sécheresse et maladies chez les arbres forestiers, avec trois grandes parties : (1) description des types d’interaction ; (2) connaissances acquises sur les mécanismes impliqués ; (3) trois études de cas bien étudiées. La première partie est basée sur l’analyse d’une base de données d’une centaine d’études, sélectionnées par recherche sur mots clés. La plupart de ces études se rapportent à des maladies favorisées par la sécheresse ou à un effet synergique entre sécheresse et maladie sur l’état sanitaire des arbres, avec une prédominance de maladies à chancres ou de rameaux, causées par des espèces des genres Botryosphaeria, Sphaeropsis, Cytospora et Biscognauxia (Hypoxylon). Un effet Interactions of ozone and pathogens on the surface structure of Norway spruce needles K. Ojanperä S. Huttunen 2 1 Department of Botany, University of Gothenburg, Carl Skottsbergs Gata 22, 41319 Gothenburg, Sweden, and 2 Department of Botany, University of Oulu, 90570 Oulu, Finland Introduction The plant surface is at the interface be- tween the plant and its atmospheric envi- ronment. The cuticle is covered by an inert layer of epicuticular wax which protects the plant from unfavorable conditions, such as frost, drought, radiation and pathogens. It also acts as a barrier to air pollutants (Jeffree, 1986). The epicuticular wax of Norway spruce current needles consists of small tubes forming an evenly dispersed wax struc- ture. As a result of natural erosion of the needle’s surface, the wax tubes agglom- erate, first forming a reticulate and then a plate-like wax structure (Sauter and Voss, 1986). The life span of healthy needles of Norway spruce varies from 7 to 17 yr (Gunthardt and Wanner, 1982). Exposure to air pollutants is known to alter the structure of epicuticular wax, resulting in erosion and increased stoma- tal occlusion (Huttunen and Laine, 1981; 1983; Crossley and Fowler, 1986). This study was undertaken to assess whether or not ozone is also a factor which induces changes in the surface structure of Nor- way spruce needles. Materials and Methods The ozone-fumigated needles of Norway spruce were obtained from 3 different fumiga- tion experiments carried out in summers 1985 and 1986 by Dr. Jurg Bucher at the Swiss Federal Institute of Forestry Research in Bir- mensdorf, Switzerland, (1985, 1986) and by Dr. Georg Krause at the Landesanstalt fur lmmis- sionschutz des Landes Nordrhein-Wesffahlen in Essen, F.R.G. (1986). In the Swiss experiments 4 yr old spruce graftings were fumigated in open top chambers with 0, 100, 200 or 300 pg of ozone/m 3 of fil- tered air during 109 or 114 weekdays using a different spruce clone each year. In the German experiment, 7 yr old spruce seedlings were fumigated continuously in open top chambers with 0, 100, 300 or 600 pg of ozone/M 3 of fil- tered air for 40 d. Samples were sputter-coated with gold-pal- ladium using a Polaron 5100 sputter coater. Coated samples were studied and photograph- ed with a Jeol JSM-35 scanning electron micro- scope (15 kV accelerating voltage, sample cur- rent 10-11 A, exposure time 100 s). Stratified micrograph (2 groups: erosion observed/not observed) material was statistically analyzed with an IBM computer using a two way frequen- cy table (BMDP P4F-program). Observed injury type was separately cross-tabulated with the ozone treatment. The statistical analysis used in the program was the non-parametrical likeli- hood-ratio chi-square test. Results When studying the effects of ozone fumi- gation, a slightly promoted surface erosion could be detected in the wax structure in epistomatal chambers. Tubular wax cover- ing the stomata was more often flat and solid under ozone exposure with concen- trations higher than 200 !g. The change was observable at the edges of the stomata (P= 0.0346). The apparently newly crystallized small wax tubes cover- ing the eroded area were typical of this type of injury (Fig. 1A and B). - Apart from the erosion of wax within sto- matal chambers, an overall erosion of the epicuticular wax could be observed that seemed to correspond to exposure to ozone. The healthy tubular wax structure, characteristic of the current yr needles, was less abundant in the ozone-fumigated Genome BBiioollooggyy 2009, 1100:: 306 Meeting report GGeennoommiicc ppaarraassiitteess aanndd ggeennoommee eevvoolluuttiioonn Zoltán Ivics Address: Max Delbrück Center for Molecular Medicine, Robert Rössle Str. 10, D-13092 Berlin, Germany. Email: zivics@mdc-berlin.de Published: 15 April 2009 Genome BBiioollooggyy 2009, 1100:: 306 (doi:10.1186/gb-2009-10-4-306) The electronic version of this article is the complete one and can be found online at http://genomebiology.com/2009/10/3/306 © 2009 BioMed Central Ltd A report of the Second International Conference/Workshop on the Genomic Impact of Eukaryotic Transposable Elements, Pacific Grove, USA, 6-10 February 2009. Transposable elements (TEs) are genetic elements with the unique ability to move in the genome. TEs are major components of the repetitive fraction of genomes; for example, TE-derived sequences make up about 45% of the human genome. The most abundant transposons in mammals are non-long terminal repeat (non-LTR) retrotransposons represented by the long interspersed nuclear elements (LINEs) and the short interspersed nuclear elements (SINEs). DNA 'cut-and-paste' transposons are less abundant in mammals, and typically encode a transposase protein in their simple genome. Transposition can be exploited to harness these elements as gene vectors for diverse genome manipulations (see the review series in a special issue of Genome Biology [http://genomebiology.com/supplements/8/S1]). Beyond their present-day use as research tools, TEs have been shaping genome structure and function for millions of years, and the impact of transposons on eukaryotic genomes was the central theme of a conference held recently at Asilomar. Nearly 40 years ago, Roy Britten (who spoke at the meeting) and Eric Davidson proposed that the spread of repetitive elements in the genome may play a key role in the evolution of gene regulatory networks. Today, TEs are no longer viewed as 'junk DNA'; they can undergo 'exaptation' (a term frequently used at the meeting), an evolutionary process in which a characteristic that evolved under natural selection for a particular function is placed under selection for a different function. For example, the feathers of birds were first used to retain heat and only later used for flight. There are now numerous examples of exaptation of TE-derived sequences described in the literature, and several were presented at the meeting. Here I cover a few of the highlights. TTrraannssppoossoonn eexxaappttaattiioonn David Haussler (University of California Santa Cruz, USA) presented data on TE sequences undergoing natural selection to control nearby genes. TEs are perfect genomic vehicles for distributing repetitive genetic material over the genome where, as Haussler pointed out, they might then act as binding sites for 'master regulators' represented by transcription factors (Figure 1). For example, binding sites for the tumor suppressor protein p53 are highly enriched in the LTRs of some human endogenous retroviruses (ERVs), and these sites represent more than 30% of the p53- binding sites in the genome. Expression of many genes that are linked to these LTRs are thus under the transcriptional control of p53. It appears, therefore, that even though many ERV insertions close to genes were selected against (probably because their effect on gene expression reduced fitness), a significant fraction became exapted to expand the p53 transcriptional network. The thought-provoking hypothesis that multiple retrotransposon insertions made our brain mammalian was put forward by Norihiro Okada (Tokyo Institute of Technology, Japan). His group has characterized a SINE family called AmnSINE1 that constitutes a conserved noncoding element in mammalian genomes, suggesting that these sequences have acquired some function useful to the host. Okada used an in vivo enhancer assay in mice to show that a SINE locus closely linked to the FGF8 (fibroblast CHAPTER I: INTRODUCTION 1.1 General introduction of autophagy 1.1.1 Process and classification of autophagy Autophagy is a cellular mechanism for bulk degradation of long-lived cytosolic or short-lived damaged proteins and organelles within vacuoles/lysosomes. Autophagy is induced in response to environmental stress or developmental signals during cellular differentiation (Besteiro et al., 2006; Liu et al., 2005; Noda and Ohsumi, 1998; PinanLucarre et al., 2003b; Pinan-Lucarre et al., 2005). Take non-selective macroautophagy as example, when autophagy is induced, cytoplasmic constituents, including organelles, are sequestered by a unique membrane called the phagophore or isolation membrane. The complete sequestration by the elongating phagophore results in formation of the autophagosome, a double-membraned organelle (300-900 nm in diameter). In the next step, autophagosomes fuse with lysosomes (in metazoan cells) or vacuoles (in yeast and plant cells). Once macromolecules have been degraded in the lysosome/vacuole, monomeric units (e.g., amino acids) are exported to the cytosol for reuse. Besides macroautophagy, non-selective autophagy includes microautophagy, which involves the direct engulfment of cytoplasm at the surface of the vacuole (Noda et al., 1995). Eukaryotic cells also exert a highly selective process to deliver specific cytosolic proteins into the vacuole, which is called cytoplasm-to-vacuole targeting (Cvt) pathway (Scott et al., 1997). A selective autopahgy that is specific for cytosolic glycogen was identified in new-born animals and was named as glycogen autophagy. Autophagy can also target specific organelles for degradation, such as ER (reticulophagy) (Bernales et al., 2007) mitochondria (mitophagy) (Tolkovsky, 2009) and peroxisomes (pexophagy) (Sakai et al., 2006) (Figure 1). 1.1.1.1 Glycogen autophagy In newborn animals, a well-defined role for autophagy is the breakdown of intracellular glycogen reserves within autophagic vacuoles, namely glycogen autophagy, which is a strategy to cope with a sudden demand for ample energy substrates to confront metabolic requirements, before gluconeogenesis is initiated (Kotoulas et al., 2004, 2006). Glycogen autophagy can be induced by glucagons, and be suppressed by insulin, which abolishes glucagon secretion (Kalamidas and Kotoulas, 2000b; Kotoulas et al., 2006). Glucagon action is activated by the cAMP / protein kinase A (which in turn activates glycogen autophagy) and suppressed by phosphoinositides / mTOR pathways (which in turn surpresses glycogen autophagy) (Kalamidas et al., 1994; Kotoulas et al., 2004). That glycogen autophagy can be induced by rapamycin in newborn rat hepatocytes also suggests a TOR-dependent regulation on glycogen autophagy (Kalamidas and Kotoulas, 2000a, b). 1.1.1.2 The Cvt pathway The Cvt, cytosol-to-vacuole targeting pathway is a selective type of autophagy that is responsible for the sequestration of at least two resident vacuolar hydrolases, aminopeptidase I (Ape1) and α-mannosidase (Ams1), as specific cargos. The Cvt vesicles (140-160 nm in diameter) are also double-membrane bound but distinct from autophagosomes in cargo selectivity and size. However, Cvt and autophagy pathways are topologically and mechanistically similar and share most of the Atg (autophagy- Figure 1. Schematic diagram of selective and non-selective autophagy. Depending on the specificity of the cargos, autophagy can be a selective or a nonselective process. During nonselective autophagy, a portion of the cytoplasm is sequestered into a double-membrane autophagosome, which then fuses with the vacuole (macroautophagy). A biosynthetic cytoplasm to vacuole targeting (Cvt) pathway in yeast also shares similar morphological features and viewed as a selective type of autophagy.In contrast, the specific degradation of peroxisomes in certain conditions can be achieved by a macro- or microautophagy-like mode, termed macropexophagy and micropexophagy, respectively. .. .Fungal Parasites and Pathogens Some fungal pathogens include (a) green mold on grapefruit, (b) powdery mildew on a zinnia, (c) stem rust on a sheaf of barley, and (d) grey rot... nuts and grains are tainted by aflatoxins, leading to massive recall of produce This sometimes ruins producers and causes food shortages in developing countries Animal and Human Parasites and Pathogens. .. and spores develop strong and dangerous allergic reactions Fungal infections are generally very difficult to treat because, unlike bacteria, 2/6 Fungal Parasites and Pathogens fungi are eukaryotes