Occurrence and Characterization of 2-Hydroxy-1,4-benzoxazin-3-one and Indole Hydroxylases in Juvenile Wheat

Tanabe, Junya; Sue, Masayuki; Ishihara, Atsushi; Iwamura, Hajime

doi:10.1271/bbb.63.1614

Cited by 14 publications

(8 citation statements)

References 13 publications

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“…As the plant starts autotrophic growth, concentrations gradually decline and substantial levels are then restricted to young tissues (8,22,67,68). A concurrent dynamics occurs for Bx gene expression and the activity of the enzymes involved in vacuolar storage and deglycosylation (9,10,51,69). Hence, an intrinsic temporal regulation of Bx biosynthesis and storage by plant age has been suggested (8,9).…”

Section: Resultsmentioning

confidence: 99%

Differential Exudation of Two BenzoxazinoidsOne of the Determining Factors for Seedling Allelopathy of Triticeae Species

Belz

Hurle

2004

J. Agric. Food Chem.

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Benzoxazinoids (Bx) are natural phytotoxins that function as chemical defense compounds in several species. The release of Bx by intact plant roots associated these compounds with root allelopathy in Triticeae species; however, the significance of exudate concentrations of Bx for plant-plant interactions is still a controversial question. A biological screening of 146 cultivars of four Triticeae species (Triticum aestivum L., Triticum durum Desf., Triticum spelta L., and Secale cereale L.) demonstrated a high cultivar dependence to suppress the root growth of Sinapis alba L. by root allelopathy in a dose-response bioassay. Only a few cultivars possessed a marked high or low allelopathic activity, whereby high-performance liquid chromatography-diode array detection analysis of root exudates revealed that these cultivars differed considerably in their ability to exude the two Bx aglucones, DIBOA [2,4-dihydroxy-2H-1,4-benzoxazin-3(4H)-one] and DIMBOA [2,4-dihydroxy-7-methoxy-2H-1,4-benzoxazin-3(4H)-one]. The total amount of DIBOA and DIMBOA exuded showed a significant correlation to the growth inhibition in bioassay with a statistically estimated contribution to the overall allelopathic effect of 48-72%. In a bioassay with pure phytotoxins, Bx concentrations consistent with the amounts quantified in the screening bioassay caused detrimental effects on S. alba and almost reproduced the statistically estimated contribution. The observed causal association between the allelopathic activity under laboratory conditions and the exudate concentrations of Bx suggests that this association might have implications for the interference of Triticeae species in natural plant communities.

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Section: Resultsmentioning

confidence: 99%

Differential Exudation of Two BenzoxazinoidsOne of the Determining Factors for Seedling Allelopathy of Triticeae Species

Belz

Hurle

2004

J. Agric. Food Chem.

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“…The maize ortholog CYP71C2 also accepts both these substances as substrates (Glawischnig et al 1999), confirming the catalytic similarity between CYP71C7v2 and CYP71C2. 1,4-Benzoxazin-3-one has been suggested to be an intermediate in the biosynthesis of Hxs, on the basis of a feeding experiment (Kumar et al 1994) and the conversion of this compound to HBOA by microsomal fractions isolated from wheat seedlings (Tanabe et al 1999). However, the V max /K m ratio of CYP71C7v2 was about 1.5 times higher for indolin-2-one than for 1,4-benzoxazin-3-one.…”

Section: Discussionmentioning

confidence: 99%

“…Some monooxygenase activities associated with the P450s in the Hx biosynthetic pathway have been detected in microsomes prepared from wheat (Tanabe et al 1999) and rye (Glawischnig et al 1999) seedlings. However, none of the genes controlling the biosynthesis of Hxs have been isolated from either wheat or rye.…”

Section: Introductionmentioning

confidence: 99%

Molecular characterization and chromosomal localization of cytochrome P450 genes involved in the biosynthesis of cyclic hydroxamic acids in hexaploid wheat

et al. 2002

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The cyclic hydroxamic acids, 2,4-dihydroxy-1,4-benzoxazin-3-one (DIBOA) and 2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one (DIMBOA), are defensive secondary metabolites found in gramineous plants including wheat, maize and rye. cDNAs for five cytochromes P450 (P450s) involved in DIBOA biosynthesis (CYP71C6, CYP71C7v2, CYP71C8v2, CYP71C9v1 and CYP71C9v2) were isolated from seedlings of hexaploid wheat [( Triticum aestivum L. cv. Chinese Spring (2n=6x=42, genomes AABBDD)] by RT-PCR and screening of a cDNA library. CYP71C9v1 and CYP71C9v2 are 97% identical to each other in amino acid and nucleotide sequences. The cloned P450 species showed 76-79% identity at the amino acid level to the corresponding maize P450 species CYP71C1-C4, which are also required for DIBOA biosynthesis. The wheat P450 cDNAs were heterologously expressed in the yeast ( Saccharomyces cerevisiae) strain AH22. Microsome fractions from yeast cells expressing these P450 species catalyzed the same reactions as their maize orthologs. The chromosomes carrying the cyp71C6- C9v1 orthologs were identified by Southern hybridization using aneuploid lines of Chinese Spring wheat. The cyp71C9v1 orthologs were located on the chromosomes of wheat homoeologous group-4. The orthologs of the other P450 genes, cyp71C7v2, cyp71C6 and cyp71C8v2, were located on group-5 chromosomes. The same P450 genes were also present in the three ancestral diploid species of hexaploid wheat, T. monococcum (AA), Aegilops speltoides [BB (approximately SS)] and Ae. squarrosa (DD).

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“…In the biomedical sciences, hydroxamic acids moieties are used in the design of therapeutics targeting cancer [12][13][14][15], cardiovascular diseases [16,17], HIV [18,19], Alzheimer's [20,21], malaria [22][23][24][25][26][27], allergic diseases [28][29][30], tuberculosis [31][32][33][34][35][36], metal poisoning [37][38][39][40], and ironoverload [41][42][43]. In addition, the hydroxamic acids have been employed as insecticides [44,45], antimicrobials [46][47][48][49][50][51][52][53], and plant growth regulators [54][55][56][57]. They are also used industrially as antioxidants [56][57]…”

Section: Introductionmentioning

confidence: 99%

Hydroxamic Acids as Pharmacological Agents

Muri¹,

Nieto²,

Sindelar³

et al. 2002

CMC

232

149

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A variety of hydroxamic acid derivatives have recently been touted for their potential use as inhibitors of hypertension, tumor growth, inflammation, infectious agents, asthma, arthritis, and more. Here we provide a comprehensive review of the basic medicinal chemistry and pharmacology of hydroxamic acid derivatives that have been examined as inhibitors of zinc metalloproteases, matrix metalloproteinases, leukotriene A(4) hydrolases, ureases, lipoxigenases, cyclooxygenases, as well as peptide deformilases.

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Occurrence and Characterization of 2-Hydroxy-1,4-benzoxazin-3-one and Indole Hydroxylases in Juvenile Wheat

Cited by 14 publications

References 13 publications

Differential Exudation of Two BenzoxazinoidsOne of the Determining Factors for Seedling Allelopathy of Triticeae Species

Differential Exudation of Two BenzoxazinoidsOne of the Determining Factors for Seedling Allelopathy of Triticeae Species

Molecular characterization and chromosomal localization of cytochrome P450 genes involved in the biosynthesis of cyclic hydroxamic acids in hexaploid wheat

Hydroxamic Acids as Pharmacological Agents

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