41 research outputs found
Cell wall modifications lead to cultivar differences in apple (Malus domestica) fruit mealiness
Recently, four quantitative trait loci linked to flesh mealiness in apples were identified, with one associated with the MdPG1 allele. Hence, this study analyzed cell wall changes in two mealy (Orin and Akane) and three non-mealy (Kiou, Kitaro, Fuji) apple cultivars during ripening. The fruits were harvested for each cultivar at optimum maturity and stored at 20°C for 20 days. The flesh firmness of ‘Kitaro’ and ‘Fuji’ fruit did not change strikingly over the 20 days, whereas that of the other three cultivars, especially ‘Akane’ and ‘Orin’, gradually decreased during ripening. Between the two cultivars with a mealy texture, ‘Akane’ fruit produced extremely low levels of ethylene, whereas ‘Orin’ fruit produced high levels. The water-soluble polyuronide (WSP) contents of ‘Kiou’ and ‘Fuji’ fruit did not change clearly. In contrast, the WSP contents of the other three cultivars, especially ‘Akane’ and ‘Orin’, increased during ripening. In ‘Kiou’, ‘Kitaro’, and ‘Fuji’ fruit, the molecular-mass distributions of WSPs did not change during ripening. Conversely, the molecular-mass distribution of WSPs in ‘Akane’ and ‘Orin’ fruit exhibited downshifts during ripening. These results indicate that solubilization and depolymerization of pectic polyuronides occur during ripening in mealy ‘Akane’ and ‘Orin’ fruit, and that ethylene may not be involved in these changes
Functional and expressional analyses of apple FLC-like in relation to dormancy progress and flower bud development.
We previously identified the FLOWERING LOCUS C (FLC)-like gene, a MADS-box transcription factor gene that belongs to Arabidopsis thaliana L. FLC clade, in apple (Malus ×domestica Borkh.), and its expression in dormant flower buds is positively correlated with cumulative cold exposure. To elucidate the role of the MdFLC-like in the dormancy process and flower development, we first characterized the phenotypes of MdFLC-like overexpressing lines with the Arabidopsis Columbia-0 background. The overexpression of MdFLC-like significantly delayed the bolting date and reduced the plant size, but it did not significantly affect the number of rosette leaves or flower organ formation. Thus, MdFLC-like may affect vegetative growth and development rather than flowering when expressed in Arabidopsis, which is not like Arabidopsis FLC that affects development of flowering. We compared seasonal expression patterns of MdFLC-like in low-chill ‘Anna’ and high-chill ‘Fuji’ and ‘Tsugaru’ apples collected from trees grown in a cold winter region in temperate zone and found an earlier upregulation in ‘Anna’ compared with ‘Fuji’ and ‘Tsugaru’. Expression patterns were also compared in relation to developmental changes in the flower primordia during the chilling accumulation period. Overall, MdFLC-like was progressively upregulated during flower primordia differentiation and development in autumn to early winter and reached a maximum expression level at around the same time as the genotype-dependent chilling requirements were fulfilled in high-chill cultivars. Thus, we hypothesize MdFLC-like may be upregulated in response to cold exposure and flower primordia development during the progress of endodormancy. Our study also suggests MdFLC-like may have a growth-inhibiting function during the end of endodormancy and ecodormancy when the temperature is low and unfavorable for rapid bud outgrowth
Knee extension muscle strength in elderly women who underwent total knee arthroplasty, and regional differences in the Japanese Orthopedic Association knee disease treatment criteria
departmental bulletin pape
Comparative Gene Analysis Focused on Silica Cell Wall Formation: Identification of Diatom-Specific SET Domain Protein Methyltransferases
Silica cell walls of diatoms have attracted attention as a source of nanostructured functional materials and have immense potential for a variety of applications. Previous studies of silica cell wall formation have identified numerous involved proteins, but most of these proteins are species-specific and are not conserved among diatoms. However, because the basic process of diatom cell wall formation is common to all diatom species, ubiquitous proteins and molecules will reveal the mechanisms of cell wall formation. In this study, we assembled de novo transcriptomes of three diatom species, Nitzschia palea, Achnanthes kuwaitensis, and Pseudoleyanella lunata, and compared protein-coding genes of five genome-sequenced diatom species. These analyses revealed a number of diatom-specific genes that encode putative endoplasmic reticulum-targeting proteins. Significant numbers of these proteins showed homology to silicanin-1, which is a conserved diatom protein that reportedly contributes to cell wall formation. These proteins also included a previously unrecognized SET domain protein methyltransferase family that may regulate functions of cell wall formation-related proteins and long-chain polyamines. Proteomic analysis of cell wall-associated proteins in N. palea identified a protein that is also encoded by one of the diatom-specific genes. Expression analysis showed that candidate genes were upregulated in response to silicon, suggesting that these genes play roles in silica cell wall formation. These candidate genes can facilitate further investigations of silica cell wall formation in diatoms
Operator Projection Theory for Electron Differentiation in Underdoped Cuprate Superconductors
Metals approaching the Mott insulator generate a new hierarchy in the
electronic structure accompanied by a momentum dependent electron
differentiation, beyond the Mott-Hubbard, Brinkman-Rice and Slater pictures of
the Mott transition. To consider such nonlinear phenomenon, we develop an
analytic nonperturbative theory based on operator projections combined with a
self-consistent treatment of the low-energy excitations. This reproduces the
formation of the Hubbard bands, Mott gap, spin fluctuations, mass divergence,
diverging charge compressibility, and strongly renormalized flat and damped
dispersion similar to angle-resolved photoemission data in high-T_c cuprates.
Main structures in electronic spectra show a remarkable similarity to numerical
results.Comment: 11 pages, presented at ``Spectroscopies of Novel Superconductors
2001'
A nationwide, multi-center, retrospective study of symptomatic small bowel stricture in patients with Crohn\u27s disease.
BACKGROUND:Small bowel stricture is one of the most common complications in patients with Crohn\u27s disease (CD). Endoscopic balloon dilatation (EBD) is a minimally invasive treatment intended to avoid surgery; however, whether EBD prevents subsequent surgery remains unclear. We aimed to reveal the factors contributing to surgery in patients with small bowel stricture and the factors associated with subsequent surgery after initial EBD.METHODS:Data were retrospectively collected from surgically untreated CD patients who developed symptomatic small bowel stricture after 2008 when the use of balloon-assisted enteroscopy and maintenance therapy with anti-tumor necrosis factor (TNF) became available.RESULTS:A total of 305 cases from 32 tertiary referral centers were enrolled. Cumulative surgery-free survival was 74.0% at 1 year, 54.4% at 5 years, and 44.3% at 10 years. The factors associated with avoiding surgery were non-stricturing, non-penetrating disease at onset, mild severity of symptoms, successful EBD, stricture length < 2 cm, and immunomodulator or anti-TNF added after onset of obstructive symptoms. In 95 cases with successful initial EBD, longer EBD interval was associated with lower risk of surgery. Receiver operating characteristic analysis revealed that an EBD interval of ≤ 446 days predicted subsequent surgery, and the proportion of smokers was significantly high in patients who required frequent dilatation.CONCLUSIONS:In CD patients with symptomatic small bowel stricture, addition of immunomodulator or anti-TNF and smoking cessation may improve the outcome of symptomatic small bowel stricture, by avoiding frequent EBD and subsequent surgery after initial EBD