Effect of different planting times on the quantitative variation of total seed isoflavone content and composition in Korean soybean cultivars (Glycine max (L.) Merr.)

Journal of Crop Science and Biotechnology - There is great interest in the enhancement of isoflavones as one of the functional ingredients in soybean. This study aimed to investigate the effects of...     

Chromosomes responsible for sensitivity of embryo to abscisic acid and dormancy in wheat

The sensitivity of the embryo to abscisic acid (ABA) has been reported toplay an important role in seed dormancy. Using ditelocentric lines of wheatcv. Chinese Spring (CS, nondormant and ABA insensitive), F₂ seedsbetween monosomic lines of CS and a wheat line Kitakei-1354 (dormant,ABA sensitive) and deletion lines of CS chromosome 4A, germinability ofseeds and embryo-half seeds incubated in water and ABA were examined. The results indicated that the long arm of chromosome 4A carried majorgene(s) for the embryo sensitivity to ABA and dormancy. Chromosome2D might be also involved in the sensitivity to ABA.     

Changes in anthocyanin and isoflavone concentrations in black seed-coated soybean at different planting locations

This study assessed the altitudinal variations in the anthocyanin and isoflavone contents of six black seed coated soybean [Glycine max (L.) Merrill] cultivars. The black soybean cultivars Heugcheong, Seonheuk, Geomjeong 1, Geomjeong 2, Cheongja 2, and Cheongja 3 were planted at Milyang (12 m above mean sea level — low altitude) and Muju (600 m — high altitude), Korea on 10 June 2005 and 2006. The total anthocyanin and isoflavone contents and individual components were investigated by reverse-phase high performance liquid chromatography (HPLC). All black soybean cultivars cultivated in high altitude possessed significantly higher total anthocyanin (p < 0.01) and isoflavone (p < 0.01) contents than those grown in low altitude. For anthocyanin composition, cyanidin-3-O-glucoside, cyanidin-3-O-galactoside, and peonidin-3-O-glucoside contents were significantly higher while delphinidin-3-O-glucoside contents was significantly lower at high altitude. The composition of individual isoflavones, 6″-O-malonyldaidzin, and 6″-O-malonylgenistin contents significantly increased at high altitude.     

A molecular technique for selection of self-compatible varieties of Japanese pear (Pyrus pyrifolia Nakai)

The pear cultivar ‘Osa-Nijisseiki’ (S₂S^sm ₄; sm = stylar-part mutant) has been used as a parent to breed self-compatible cultivars that produce excellent fruits. However, determination of the self-compatibility of ‘Osa-Nijisseiki’ offspring requires a lot of time, 6 years or more, by conventional cross breeding. We have designed a rapid reliable method for the identification of self-compatible varieties of ‘Osa-Nijisseiki’ offspring based on the polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) with S-allele specific restriction endonucleases. By using this method, 8 self-compatible varieties were selected among 16 selections resulting from a cross between the self-compatible cultivar ‘Osa-Nijisseiki’ (S₂S^sm ₄) and the self-incompatible cultivars ‘Niitaka’ (S₃S₉), ‘Whasan’ (S₃S₅), ‘Chuwhangbae’ (S₄S₆). The S-genotypes of 16 ‘Osa-Nijisseiki’ offsprings were also determined. This revised version was published online in August 2006 with corrections to the Cover Date.     

Effect of proton beam irradiation on germination, seedling growth, and pasting properties of starch in rice

This study was carried out to determine the pretreatment effect of proton beam irradiation on germination and pasting properties of starches in two rices. Mature and healthy seeds irradiated with 10 doses (0, 50, 100, 200, 300, 400, 500, 600, 700, and 800 Gy) for determination of LD50 and characteristics of germination were recorded at 14 days after irradiation. The rice seeds irradiated with five doses (0, 50, 100, 200, and 300 Gy) were used to evaluate the irradiation effects of pasting properties of starches. It showed that a lower survival rate in germinated rice seeds was observed above 300 Gy showing 31 and 35% in Ilpum and Hanmaum, respectively. The higher plant height and root length were also recorded in 50 and 100 Gy. Amylose content in proton beam irradiated with 50, 100, 200, and 300 Gy was significantly decreased in two rice cultivars. Peak viscosity, hot peak viscosity, cooling peak viscosity, and setback viscosity decreased with increasing proton beam dose levels. The degree of crystallinity was significantly increased with increasing proton beam dose levels. Consequently, it might be deduced that proton beam irradiation causes changes of starch properties affecting crystalline regions of starch granules, especially at high dosage irradiation.     

Proteomic identification of a novel toxin protein (Txp40) from Xenorhabdus nematophila and its insecticidal activity against larvae of Plutella xylostella

For the identification of a novel insecticidal protein, a two-dimensional liquid chromatography (PF-2D) system was used in a quantitative proteomic analysis of Xenorhabdus nematophila CBNU strain isolated from entomophagous nematode Steinernema carpocapsae . Protein patterns obtained from minimum and maximum insecticidal activities during cultivation were contrasted, and a novel toxin protein (Txp40) was identified by MALDI-TOF/MS. The DNA sequence of the cloned toxin gene (1089 bp) has an open reading frame encoding 363 amino acids with a predicted molecular mass of 41162 Da. The txp40 identified in this study is most closely related to the known txp40 cloned from X. nematophila EB (ADQ92844) with 94.4% identical sequence residues. Following the expression of the newly identified toxin gene in Escherichia coli , the insecticidal activity of the recombinant toxin protein was determined against Plutella xylostella larvae; a 56.7% mortality rate was observed within 24 h.     

Management of pine wilt disease in Korea through preventative silvicultural control

Pine wilt disease (PWD) represents a major threat to forest ecosystems worldwide. Although PWD is now better understood, effective control measures for this disease have still not been devised. Here, we report several years of field studies on preventative silvicultural control of PWD. Silvicultural control through preventative clear-cutting and the manual removal of logs was implemented between 2005 and 2009 in 16 Korean districts that had newly PWD-infected stands. Preventative clear-cutting of neighboring asymptomatic pine trees (within a 10-50-m radius of wilt trees) and the removal of felled logs or branches suppressed spread of PWD. Occurrences of PWD wilt pines in districts (city or county) subjected to this silvicultural control method were significantly reduced compared with those in districts using conventional controls (physical or chemical treatment of wilt pine trees). Through silvicultural control, PWD was successfully suppressed in 11 of 16 districts investigated. In contrast, successful control was achieved in only 1 among 18 districts subjected to conventional control. Our results will be of considerable interest to those engaged in the very difficult battle against the global spread of PWD.     

Hyperhydricity in apple: ultrastructural and physiological aspects

We studied the effects of hyperhydricity on subcellular ultrastructure and physiology of leaves during in vitro regeneration of apple plants. Morphological, anatomical and ultrastructural differences between healthy leaf tissues obtained from greenhouse-grown plants and healthy and hyperhydric leaves obtained from shoots raised from nodal shoot explants in a bioreactor were investigated by electron microscopy and confocal laser scanning microscopy. Compared with healthy leaves, hyperhydric leaves showed abnormal, often discontinuous development of the epidermis and cuticle. Stomata were malformed. The leaf lamina appeared thickened and was characterized by poor differentiation between the palisade and spongy mesophyll tissue. Hyperhydric leaves had a significantly lower chloroplast number per cell and chloroplasts showed reduced thylakoid stacking compared with healthy leaves. Hyperhydricity resulted in a general decrease in concentrations of reduced and oxidized pyridine nucleotides, reflecting a reduction in metabolic activity. The activities of antioxidant enzymes, such as superoxide dismutase, catalase, ascorbate peroxidase and glutathione reductase were higher in hyperhydric leaves than in healthy leaves, indicating that hyperhydricity was associated with oxidative stress. Chlorophyll fluorescence measurements provided evidence of oxidative damage to the photosynthetic machinery in hyperhydric leaves: photochemical efficiency of photosystem II, effective quantum efficiency and photochemical quenching were all lower in hyperhydric leaves compared with healthy leaves.