Inducible Phytoalexins in Juvenile Soybean Genotypes Predict Soybean Looper Resistance in the Fully Developed Plants

Liu, Shaohua; Norris, Dale M.; Hartwig, E. E.; Xu, Mian

doi:10.1104/pp.100.3.1479

Cited by 32 publications

(17 citation statements)

References 24 publications

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“…The occurrence of pests and diseases was controlled, and the harvest of leaf material of a particular plant was followed by at least 4 wk until the next harvest of leaves to minimize possible effects of various induced defense mechanisms known from the Fabaceae (Fischer et al, 1990;Liu et al, 1992;Underwood, 1999;Underwood et al, 2000;Heil, 2004).…”

Section: Methodsmentioning

confidence: 99%

Plant Cyanogenesis of Phaseolus lunatus and its Relevance for Herbivore–Plant Interaction: The Importance of Quantitative Data

2005

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Abstract-Quantitative experimental results on the antiherbivorous effect of cyanogenesis are rare. In our analyses, we distinguished between the total amount of cyanide-containing compounds stored in a given tissue [cyanogenic potential (HCNp)] and the capacity for release of HCN per unit time (HCNc) from these cyanogenic precursors as a reaction to herbivory. We analyzed the impact of these cyanogenic features on herbivorous insects using different accessions of lima beans (Phaseolus lunatus L.) with different cyanogenic characteristics in their leaves and fourth instars of the generalist herbivore Schistocerca gregaria Forskål (Orthoptera, Acrididae). Young leaves exhibit a higher HCNp and HCNc than mature leaves. This ontogenetic variability of cyanogenesis was valid for all accessions studied. In no-choice bioassays, feeding of S. gregaria was reduced on high cyanogenic lima beans compared with low cyanogenic beans. A HCNp of about 15 mmol cyanide/g leaf (fresh weight) with a corresponding HCNc of about 1 mmol HCN released from leaf material within the first 10 min after complete tissue disintegration appears to be a threshold at which the first repellent effects on S. gregaria were observed. The repellent effect of cyanogenesis increased above these thresholds of HCNp and HCNc. No repellent action of cyanogenesis was observed on plants with lower HCNp and HCNc. These low cyanogenic accessions of P. lunatus were consumed extensivelyVwith dramatic consequences for the herbivore. After consumption, locusts showed severe symptoms of intoxication. Choice assays confirmed the feeding preference of locusts for low over high cyanogenic leaf material of P. lunatus. The bioassays revealed total 0098-0331/05/0700-1445/0 # 2005 Springer Science + Business Media, Inc. 1445Journal of Chemical Ecology, Vol. 31, No. 7, July 2005 DOI: 10.1007/s10886-005-5791-2 * To whom correspondence should be addressed. E-mail: dballhorn@iangbot.uni-hamburg.de losses of HCN between 90 and 99% related to the estimated amount of ingested cyanide-containing compounds by the locusts. This general finding was independent of the cyanogenic status (high or low) of the leaf material.

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Section: Methodsmentioning

confidence: 99%

Plant Cyanogenesis of Phaseolus lunatus and its Relevance for Herbivore–Plant Interaction: The Importance of Quantitative Data

2005

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“…However, no significant difference in the incidence of Orius spp., including O. sauteri, was detected between the GM and conventional varieties in either year. Thus, bottom-up effects such as morphological and chemical differences among the soybean varieties could be responsible for the difference (Hara and Ohba, 1981;Hart et al, 1983;Hulburt et al, 2004;Khan et al, 1986;Kobayashi, 1972;Liu et al, 1992; Smith, GM glyphosate-tolerant soybean impacts on field arthropods 1985; Tester, 1977;Turnipseed, 1977). However, we did not attempt to identify the factor or factors responsible for the differences in the incidence of Thysanoptera or in the total arthropod incidence, both of which were significantly larger on the GM varieties.…”

Section: Discussionmentioning

confidence: 99%

“…However, we did not attempt to identify the factor or factors responsible for the differences in the incidence of Thysanoptera or in the total arthropod incidence, both of which were significantly larger on the GM varieties. It is likely that morphological and chemical differences among conventional varieties that are capable of affecting arthropod incidences are ubiquitous, independent of genetic modification (Hara and Ohba, 1981;Hulburt et al, 2004;Khan et al, 1986;Liu et al, 1992;Smith, 1985;Tester, 1977;Turnipseed, 1977).…”

Section: Discussionmentioning

confidence: 99%

Assessing the effects of cultivating genetically modified glyphosate-tolerant varieties of soybeans (Glycine max(L.) Merr.) on populations of field arthropods

Imura

Shi

Iimura

et al. 2010

Environ. Biosafety Res.

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We assessed the effects of cultivating two genetically modified (GM) glyphosate-tolerant soybean varieties (Glycine max (L.) Merr.) derived from Event 40-3-2 and a Japanese conventional variety on arthropods under field conditions, with weed control using glyphosate and conventional weed control for two years. Plant height and dry weight of the conventional variety were significantly larger than those of the GM varieties, but the GM varieties bore more pods than the conventional variety. We found arthropods of nine taxonomic orders (Araneae, Acari, Thysanoptera, Homoptera, Heteroptera, Coleoptera, Diptera, Lepidoptera, and Hymenoptera) on the plants. The arthropod incidence (number per plant unit weight pooled for each taxonomic order) on the soybean stems and leaves generally did not differ significantly between the GM and conventional varieties. However, the incidence of Thysanoptera and total incidence (all orders combined) were greater on the GM variety in the second year. The weed control regimes had no significant influence on the arthropod incidence on the soybean stems and leaves. The number of flower-inhabiting Thysanoptera (the dominant arthropod in the flowers) was not significantly different between the GM and conventional varieties. Asphondylia yushimai (Diptera, Cecidomyiidae) was more numerous on the pods of the GM variety in both years. Neither the soybean variety nor the weed control regime significantly affected the density of soil macro-organisms. However, the glyphosate weed control affected arthropods between the rows of plants by decreasing the abundances of Homoptera, Heteroptera, Coleoptera and Lepidoptera, and diversity of arthropods.

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“…Glyceollin has anti-pathogen activity (Lygin et al 2010) and it has been associated with resistance against nematodes (Veech 1982). It also appears to function as a feeding deterrent against insects (Hart et al 1983, Liu et al 1992.…”

Section: Introductionmentioning

confidence: 98%

“…The synthesis of glyceollin, however, is not limited to leaves. Glyceollin accumulates in roots in response to pathogen infection (Hahn et al 1985, Boué et al 2000 and nematode inoculation (Huang and Barker 1991, Kaplan et al 1980a, 1980b and is induced in hypocotyls by various chemical elicitors (Liu et al 1992). It is therefore important to study the expression of CYP93A1 in other tissues as it may be an important defense response marker in these tissues.…”

Section: Introductionmentioning

confidence: 99%

Cytochrome P<sub>450</sub>, CYP93A1, as defense marker in soybean

et al. 2016

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CYP93A1 is a cytochrome P 450 that is involved in the synthesis of the phytoalexin glyceollin in soybean (Glycine max L. Merr). The gene encoding CYP93A1 has been used as a defense marker in soybean cell cultures, however, little is known regarding how this gene is expressed in the intact plant. To further understand the tissue-specific role of CYP93A1 in soybean defense, we analyzed the expression of this gene in mechanically damaged leaves and stems. In leaves, CYP93A1 was constitutively expressed; its expression did not change in response to mechanical damage. In stems, however, expression of CYP93A1 was induced as quickly as 4 h after mechanical damage and remained upregulated for at least 48 h. The induction of CYP93A1 was associated with the synthesis of glyceollin. In comparison to several other defense-related genes encoding cysteine protease inhibitors L1 and R1 and storage proteins vspA and vspB, CYP93A1 was the most strongly induced by stem wounding. The induction of CYP93A1 was only observed locally, not systemically. Similar stem expression patterns were consistently observed among three different soybean genotypes. The strong induction of CYP93A1 in mechanically damaged stems suggests an important role in the soybean stem defense response; therefore, this study expands the use of CYP93A1 as a defense response marker to stems, not just soybean cell cultures.

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Inducible Phytoalexins in Juvenile Soybean Genotypes Predict Soybean Looper Resistance in the Fully Developed Plants

Abstract: ABSTRACT

Cited by 32 publications

References 24 publications

Plant Cyanogenesis of Phaseolus lunatus and its Relevance for Herbivore–Plant Interaction: The Importance of Quantitative Data

Plant Cyanogenesis of Phaseolus lunatus and its Relevance for Herbivore–Plant Interaction: The Importance of Quantitative Data

Assessing the effects of cultivating genetically modified glyphosate-tolerant varieties of soybeans (Glycine max(L.) Merr.) on populations of field arthropods

Cytochrome P<sub>450</sub>, CYP93A1, as defense marker in soybean

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