| jasmonate is essential for insect defense in arabidopsis. | the signaling pathways that allow plants to mount defenses against chewing insects are known to be complex. to investigate the role of jasmonate in wound signaling in arabidopsis and to test whether parallel or redundant pathways exist for insect defense, we have studied a mutant (fad3-2 fad7-2 fad8) that is deficient in the jasmonate precursor linolenic acid. mutant plants contained negligible levels of jasmonate and showed extremely high mortality ( approximately 80%) from attack by larvae of ... | 1997 | 11038546 |
| plant defense in the absence of jasmonic acid: the role of cyclopentenones. | the arabidopsis opr3 mutant is defective in the isoform of 12-oxo-phytodienoate (opda) reductase required for jasmonic acid (ja) biosynthesis. oxylipin signatures of wounded opr3 leaves revealed the absence of detectable 3r,7s-ja as well as altered levels of its cyclopentenone precursors opda and dinor opda. in contrast to ja-insensitive coi1 plants and to the fad3 fad7 fad8 mutant lacking the fatty acid precursors of ja synthesis, opr3 plants exhibited strong resistance to the dipteran bradysia ... | 2001 | 11592974 |
| interactions between spinacia oleracea and bradysia impatiens: a role for phytoecdysteroids. | plant produced insect molting hormones, termed phytoecdysteroids (pes), are thought to function as plant defenses against insects by acting as either feeding deterrents or through developmental disruption. in spinach (spinacia oleracea), 20-hydroxyecdysone (20e) concentrations in the roots rapidly increase following root damage, root herbivory, or methyl jasmonate (mj) applications. in this inducible system, we investigated the plant defense hypothesis by examining interactions of roots, 20e con ... | 2002 | 12432520 |
| fungus gnat feeding and mechanical wounding inhibit pythium aphanidermatum infection of geranium seedlings. | abstract a series of laboratory tests were conducted to investigate potential effects of fungus gnat (bradysia impatiens) feeding damage on susceptibility of geranium seedlings (pelargonium x hortorum) to infection by the root rot pathogen pythium aphanidermatum. effects were compared with those from similar tests in which the seedlings were mechanically wounded by severing the root tip with a scalpel. assays of geranium seedlings in petri dishes revealed a pronounced negative fungus gnat-pythiu ... | 2009 | 19900009 |
| transstadial transmission of pythium in bradysia impatiens and lack of adult vectoring capacity. | fungus gnats have been shown to transmit a variety of plant-pathogenic fungi that produce aerial dispersal stages. however, few studies have examined potential interactions between fungus gnats and oomycetes, including pythium spp. a series of laboratory experiments were conducted to determine whether fungus gnat adults are vectors of several common greenhouse pythium spp., including pythium aphanidermatum, p. irregulare, and p. ultimum. an additional objective was to determine whether p. aphani ... | 2010 | 20718667 |
| biology and feeding requirements of larval hunter flies coenosia attenuata (diptera: muscidae) reared on larvae of the fungus gnat bradysia impatiens (diptera: sciaridae). | the larval feeding requirements and biology of the generalist predatory muscid hunter fly coenosia attenuata stein 1903 (diptera: muscidae) were investigated at 25 degrees c. larval c. attenuata were fed second-, third, and fourth-instar (l2, l3, and l4) larvae of the fungus gnat bradysia impatiens (johannsen) (diptera: sciaridae) at variable rates to determine minimum and optimum numbers of these prey required for normal development. the proportion of c. attenuata larvae surviving to pupation d ... | 2010 | 20857722 |
| Larval Bradysia impatiens (Diptera: Sciaridae) potential for vectoring Pythium root rot pathogens. | A series of laboratory experiments were conducted to investigate the capacity of Bradysia impatiens (Johannsen) larvae to ingest propagules from two strains each of Pythium aphanidermatum (Edson) Fitzp. and P. ultimum Trow and transmit the pathogens to healthy geranium seedlings on a filter-paper substrate in Petri dishes. The capacity of fungus gnat larvae to transmit P. aphanidermatum to seedlings rooted in a commercial peat-based potting mix and germination of Pythium oospores and hyphal swe ... | 2011 | 22085299 |
| effects of short-term heat shock and physiological responses to heat stress in two bradysia adults, bradysia odoriphaga and bradysia difformis. | bradysia odoriphaga and bradysia difformis are devastating pests of vegetable, ornamental crops and edible mushrooms causing significant losses. temperature may be an important factor restricting their population abundance in the summer. to determine the effects of short-term heat shock on adults, their survival, longevity and fecundity data were collected, and antioxidant responses and heat shock protein expression levels were examined. our results indicated that the survival rates of bradysia ... | 2017 | 29042590 |