Notes - Corn Plant Resistance Factor

Smissman, Edward E.; LaPidus, Jules B.; Beck, Stanley D.

doi:10.1021/jo01353a036

Cited by 28 publications

(9 citation statements)

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“…An exception are the benzoxazinoid hydroxamic acids such as 2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one (DIMBOA). In the 1950s benzoxazinoid products were identified as factors for resistance against Fusarium rot in rye (Secale cereale) and leaf feeding by Ostrinia nubilalis in maize (Virtanen and Hietala, 1955;Smissman et al, 1957). The biosynthetic pathway through which indole, generated by an indole-3-glycerol phosphate lyase (BENZOXAZINE-DEFICIENT1 [BX1]), is decorated by a series of cytochrome P450 enzymes to yield benzoxazinoids has been elucidated since in detail (Frey et al, 1997Melanson et al, 1997;Niemeyer, 2009).…”

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confidence: 99%

Novel Acidic Sesquiterpenoids Constitute a Dominant Class of Pathogen-Induced Phytoalexins in Maize

et al. 2011

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Nonvolatile terpenoid phytoalexins occur throughout the plant kingdom, but until recently were not known constituents of chemical defense in maize (Zea mays). We describe a novel family of ubiquitous maize sesquiterpenoid phytoalexins, termed zealexins, which were discovered through characterization of Fusarium graminearum-induced responses. Zealexins accumulate to levels greater than 800 μg g−1 fresh weight in F. graminearum-infected tissue. Their production is also elicited by a wide variety of fungi, Ostrinia nubilalis herbivory, and the synergistic action of jasmonic acid and ethylene. Zealexins exhibit antifungal activity against numerous phytopathogenic fungi at physiologically relevant concentrations. Structural elucidation of four members of this complex family revealed that all are acidic sesquiterpenoids containing a hydrocarbon skeleton that resembles β-macrocarpene. Induced zealexin accumulation is preceded by increased expression of the genes encoding TERPENE SYNTHASE6 (TPS6) and TPS11, which catalyze β-macrocarpene production. Furthermore, zealexin accumulation displays direct positive relationships with the transcript levels of both genes. Microarray analysis of F. graminearum-infected tissue revealed that Tps6/Tps11 were among the most highly up-regulated genes, as was An2, an ent-copalyl diphosphate synthase associated with production of kauralexins. Transcript profiling suggests that zealexins cooccur with a number of antimicrobial proteins, including chitinases and pathogenesis-related proteins. In addition to zealexins, kauralexins and the benzoxazinoid 2-hydroxy-4,7-dimethoxy-1,4-benzoxazin-3-one-glucose (HDMBOA-glucose) were produced in fungal-infected tissue. HDMBOA-glucose accumulation occurred in both wild-type and benzoxazine-deficient1 (bx1) mutant lines, indicating that Bx1 gene activity is not required for HDMBOA biosynthesis. Together these results indicate an important cooperative role of terpenoid phytoalexins in maize biochemical defense.

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confidence: 99%

Novel Acidic Sesquiterpenoids Constitute a Dominant Class of Pathogen-Induced Phytoalexins in Maize

et al. 2011

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“…The lack of improvement may result from either incomplete extraction of the toxic substance or the presence of a further toxic factor soluble in ethanol. Ether-soluble substances toxic to insects and micro-organisms have been found in corn (SMISSMAN, LAPIDUS, & BECK, 1957), wheat seedlings (VIRTANEN, HI~XALa, & WAHLROOS, 1957), and wheat straw (LINGAPPA 8: LOCKWOOD, 1962). Perhaps then, growth on pith was not improved after removal of the toxic substance because pith is originally nutritionally inadequate.…”

Section: Resultsmentioning

confidence: 99%

“…A few insects were not killed by the ether-soluble substance(s) and appear to have grown at rates approaching those of larvae fed diets not containing ether extract. Ether-soluble substances toxic to insects and micro-organisms have been found in corn (SMISSMAN, LAPIDUS, & BECK, 1957), wheat seedlings (VIRTANEN, HI~XALa, & WAHLROOS, 1957), and wheat straw (LINGAPPA 8: LOCKWOOD, 1962). The nature of the ether-soluble toxic substance found in wheat stems remains to be determined.…”

Section: Resultsmentioning

confidence: 99%

COMPARISON OF TISSUES FROM SOLID‐ AND HOLLOWSTEMMED SPRING WHEATS DURING GROWTH: III. AN ETHER‐SOLUBLE SUBSTANCE TOXIC TO LARVAE OF THE PALE WESTERN CUTWORM, AGROTIS ORTHOGONIA MORR. (LEPIDOPTERA: NOCTUIDAE)

McGinnis¹,

Kasting²

1962

Entomologia Exp Applicata

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Feeding studies were conducted with newly hatched larvae of the pale western cutworm to determine why diets prepared from some lyophilized tissues of wheat stems allowed only poor growth and development. The nutritional value of pith from a solid-stemmed wheat was improved only slightly if at all by adding substances such as casein, yeast extract, a mixture of B-vitamins or a mixture of amino acids. Results obtained when larvae were fed a pith diet supplemented with an aqueous extract of lyophilized sprouts indicated that a nutritional deficiency alone was not responsible for the poor growth of larvae on pith. Pith was therefore extracted with diethyl ether and then with 80 per cent ethanol. Feeding studies with the ,different fractions support the view that a toxic substance, as yet undetermined, is present. Toxic substance(s) that are soluble in ether and inhibit development of cutworm larvae were also present in wall tissue of the solid-stemmed and the whole stem of the hollow-stemmed variety.

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“…Subsequently coixol was identified as 6-methoxy-2-benzoxazolinone (XX) (43). Shortly thereafter, Virtanen et al (44) isolated XX from wheat and corn while Smissman et al (45,46) Hietala and Wahlroos (48) also had succeeded in synthesizing XX prior to Smissman et al although both groups used different synthetic pathways. Subsequently, Wahlroos and Virtanen (49, 50) isolated precursors of XX from maize seedlings.…”

Section: XIXmentioning

confidence: 99%