Recovery of herbicide-resistant Azuki bean [Vigna angularis (Wild.), Ohwi & Ohashi] plants via Agrobacterium-mediated transformation

Transgenic azuki bean [Vigna angularis (Willd.) Ohwi & Ohashi] plants expressing the hygromycin phosphotransferase (hpt), green fluorescent protein (sgfp) and phosphinothricin acetyltransferase (bar) genes were obtained by Agrobacterium- tumefacients - mediated transformation. A total of 210 epicotyl explants were inoculated with A. tumefaciens strain EHA105, harboring the binary plasmid pZHBG on MS co-cultivation medium supplemented with 100 mM acetosyringone and 10 mg/l of BA. Following selection on MS medium with 15 mg/l of hygromycin, the regenerated adventitious shoots that formed on the induced calli were further screened for sgfp expression before transferred to rooting medium. 31 transgenic plants were obtained with transformation frequency of 14%. The presence of transgenes in transformed azuki bean plants was confirmed by polymerase chain reaction (PCR) and southern blot analysis. Transcription of the bar and hpt genes was assessed by reverse transcription polymerase chain reaction (RT-PCR) analysis. sgfp- positive transgenic plants exhibited functional expression of the bar gene as determined by assaying for resistance to bialaphos applied directly to leaves. This result demonstrates the feasibility of introducing potentially useful agronomic traits into azuki bean through genetic engineering. Key Words: Agrobacterium tumefaciens, bar gene, bialaphos, transgenic, Vigna angulazris. African Journal of Biotechnology Vol.4(1) 2005: 61-6

Insect-induced daidzein, formononetin and their conjugates in soybean leaves.

In response to attack by bacterial pathogens, soybean (Gylcine max) leaves accumulate isoflavone aglucones, isoflavone glucosides, and glyceollins. In contrast to pathogens, the dynamics of related insect-inducible metabolites in soybean leaves remain poorly understood. In this study, we analyzed the biochemical responses of soybean leaves to Spodoptera litura (Lepidoptera: Noctuidae) herbivory and also S. litura gut contents, which contain oral secretion elicitors. Following S. litura herbivory, soybean leaves displayed an induced accumulation of the flavone and isoflavone aglycones 4',7-dihyroxyflavone, daidzein, and formononetin, and also the isoflavone glucoside daidzin. Interestingly, foliar application of S. litura oral secretions also elicited the accumulation of isoflavone aglycones (daidzein and formononetin), isoflavone 7-O-glucosides (daidzin, ononin), and isoflavone 7-O-(6'-O-malonyl-β-glucosides) (malonyldaidzin, malonylononin). Consistent with the up-regulation of the isoflavonoid biosynthetic pathway, folair phenylalanine levels also increased following oral secretion treatment. To establish that these metabolitic changes were the result of de novo biosynthesis, we demonstrated that labeled (13C9) phenylalanine was incorporated into the isoflavone aglucones. These results are consistent with the presence of soybean defense elicitors in S. litura oral secretions. We demonstrate that isoflavone aglycones and isoflavone conjugates are induced in soybean leaves, not only by pathogens as previously demonstrated, but also by foliar insect herbivory

Evaluation of antixenosis in soybean against <i>Spodoptera litura</i> by dual-choice assay aided by a statistical analysis model: Discovery of a novel antixenosis in Peking

The method for evaluating soybean (Glycine max) antixenosis against the common cutworm (Spodoptera litura) was developed based on a dual-choice assay aided by a statistical analysis model. This model was constructed from the results of a dual-choice assay in which Enrei, a soybean cultivar susceptible to S. litura, was used as both a standard and a test leaf disc for 2nd–5th instar larvae. The statistical criterion created by this model enabled the evaluation of the presence of antixenosis. This method was applied to four soybean varieties, including Tamahomare (susceptible), Himeshirazu (resistant), IAC100 (resistant), and Peking (unknown), as well as Enrei. Subsequently, the degrees of antixenosis were also compared by F-test, followed by maximum likelihood estimation (MLE). According to the results, the antixenosis of Tamahomare, Himeshirazu, and IAC100 was statistically reevaluated and Peking exhibited a novel antixenosis, which was stronger for 3rd–5th instar larvae than for 2nd instar

ガンマセン ショウシャ ニ ヨッテ ユウハツ サレタ イネ イヘンセイ サイリュウ トツゼン ヘンイ ノ イデン

京都大学0048新制・論文博士博士(農学)乙第10688号論農博第2370号新制||農||826(附属図書館)学位論文||H13||N3556(農学部図書室)UT51-2001-F486(主査)教授 谷坂 隆俊, 教授 矢澤 進, 教授 遠藤 隆学位規則第4条第2項該当Doctor of Agricultural ScienceKyoto UniversityDFA

Full Length Research Paper - Recovery of herbicide-resistant Azuki bean [Vigna angularis (Wild.), Ohwi & Ohashi] plants via Agrobacterium- mediated transformation

Transgenic azuki bean [Vigna angularis (Willd.) Ohwi & Ohashi] plants expressing the hygromycin phosphotransferase (hpt), green fluorescent protein (sgfp) and phosphinothricin acetyltransferase (bar) genes were obtained by Agrobacterium - tumefacients - mediated transformation. A total of 210 epicotyl explants were inoculated with A. tumefaciens strain EHA105, harboring the binary plasmid pZHBG on MS co-cultivation medium supplemented with 100 mM acetosyringone and 10 mg/l of BA. Following selection on MS medium with 15 mg/l of hygromycin, the regenerated adventitious shoots that formed on the induced calli were further screened for sgfp expression before transferred to rooting medium. 31 transgenic plants were obtained with transformation frequency of 14%. The presence of transgenes in transformed azuki bean plants was confirmed by polymerase chain reaction (PCR) and southern blot analysis. Transcription of the bar and hpt genes was assessed by reverse transcription polymerase chain reaction (RT-PCR) analysis. sgfp- positive transgenic plants exhibited functional expression of the bar gene as determined by assaying for resistance to bialaphos applied directly to leaves. This result demonstrates the feasibility of introducing potentially useful agronomic traits into azuki bean through genetic engineering

QTLs underlying the genetic interrelationship between efficient compatibility of <i>Bradyrhizobium</i> strains with soybean and genistein secretion by soybean roots

<div><p>Soybean plants establish symbiotic relationships with soil rhizobia which form nodules on the plant roots. Nodule formation starts when the plant roots exudate isoflavonoids that induce <i>nod</i> gene expression of a specific <i>Bradyrhizobium</i>. We examined the specific indigenous rhizobia that form nodules with the soybean cultivars Peking and Tamahomare in different soils. PCR-RFLP analysis targeted to the 16S-23S rRNA gene internal transcribed spacer (ITS) region of the bacterial type of each root nodule showed that <i>Bradyrhizobium japonicum</i> (USDA110-type) and <i>Bradyrhizobium elkanii</i> (USDA94-type) had high compatibility with the Tamahomare and Peking cultivars, respectively. We grew 93 recombinant inbred lines (RIL) of soybean seeds derived from the cross between Peking and Tamahomare in three different field soils and identified the indigenous rhizobia nodulating each line using the same PCR-RFLP analysis. QTL analysis identified one QTL region in chromosome-18 with a highly significant additive effect that controls compatibility with both <i>B</i>. <i>japonicum</i> USDA110 and <i>B</i>. <i>elkanii</i> USDA94. We also measured the amount of daidzein and genistein secretion from roots of the 93 RILs by HPLC analysis. QTL analysis showed one QTL region in chromosome-18 controlling genistein secretion from roots and coinciding with that regulating compatibility of specific indigenous rhizobia with soybean. The amount of genistein may be a major regulatory factor in soybean-rhizobium compatibility.</p></div

Relationship between genistein secretion and percentage of UDSA110-type and USDA94-type nodules from three independent experiments.

<p>Relationship between genistein secretion and percentage of UDSA110-type and USDA94-type nodules from three independent experiments.</p

Identification of β-phenylalanine as a non-protein amino acid in cultivated rice, Oryza sativa

Non-protein amino acids, often analogs of the standard 20 protein amino acids, have been discovered in many plant species. Recent research with cultivated rice (Oryza sativa) identified (3R)-β-tyrosine, as well as a tyrosine amino mutase that synthesizes (3R)-β-tyrosine from the protein amino acid (2S)-α-tyrosine. Gas chromatography-mass spectrometry (GC-MS) assays and comparison to an authentic standard showed that β-phenylalanine is also a relatively abundant non-protein amino acid in rice leaves and that its biosynthesis occurs independently from that of β-tyrosine

Proportion (%) of bacterial types in nodules from Tamahomare, Peking and RILs from the three independent experiments.

<p>Proportion (%) of bacterial types in nodules from Tamahomare, Peking and RILs from the three independent experiments.</p

Identified QTLs controlling daidzein and genistein secretions from roots detected by means of composite interval mapping in the PT-RIL population.

<p>Identified QTLs controlling daidzein and genistein secretions from roots detected by means of composite interval mapping in the PT-RIL population.</p