This study was performed to examine differences in cold hardiness, carbohydrate content, and β-amylase gene expression during cold acclimation and deacclimation in shoots of two peach cultivars (Prunus persica 'Daewol' and 'Kiraranokiwami'). During cold acclimation (from September to November 2011), cold hardiness of the cultivars as determined by electrolyte leakage analysis increased dramatically. Maximum cold hardiness was reached at the end of December 2011 in both cultivars. During deacclimation (late January to April 2012), the cold hardiness of both cultivars decreased gradually. According to the temperatures at which 50% injury occurred (LT 50 ), there was a noticeable difference in cold hardiness between 'Daewol' and 'Kiraranokiwami' during the deacclimation period from the end of January 2012. Cold hardiness was significantly associated with total soluble sugar, sucrose, and β-amylase gene expression in both cultivars. Sorbitol, the most abundant soluble sugar, was not associated with cold hardiness in either cultivar. Glucose and fructose contents in 'Daewol', which was more freezing-tolerant, were approximately double those in 'Kiraranokiwami' from January to February 2012. These results suggest that the conversion of sucrose to glucose and fructose might be correlated with the difference of cold hardiness during deacclimation in these peach cultivars.

This study was performed to investigate the effect of the chloroform fraction from Actinidia arguta (CFAA) on cognitive dysfunction in a C57BL/6 mouse model fed a high-fat diet (HFD) for 12 weeks. The CFAA has the protective effect on high glucose-induced neurotoxicity in MC-IXC cell (neuroblastoma cell line). In a C57BL/6 mouse model fed a HFD for 12 weeks, the improved glucose tolerance and cognitive dysfunction were observed in a group ingesting CFAA. In the brain tissue analysis, the impaired cholinergic, antioxidant system and mitochondria functions were improved in the CFAA group. In addition, in a molecular biology study, it was observed that CFAA improves HFD-induced abnormal insulin signaling such as increase of IRS phosphorylation at serine residues and reduction of Akt phosphorylation caused by the increase of JNK phosphorylation and then inhibited apoptosis. In the UPLC Q-TOF/MS analysis, pentacyclic triterpenoids such as asiatic acid (AA), madecassic acid (MA) were identified in CFAA as main compounds. Therefore, these results propose that Actinidia arguta rich in pentacyclic triterpenoids may be effective as preventive matter a therapeutic strategy to improve neurodegenerative disease caused by HFD.

The relationship between cold hardiness and expression of dehydrin genes in the shoots of four peach cultivars (Prunus persica 'Daewol', 'Aikawanakajima', 'Fukuyokabijin', and 'Kiraranokiwami') was quantitatively evaluated during seasonal cold acclimation and deacclimation. Cold hardiness was determined by electrolyte leakage analysis, which increased gradually during fall, reached a maximum level in midwinter, and decreased again in spring. According to the temperatures at which 50% injury occurred (LT50), differences in cold hardiness of 'Daewol' and 'Kiraranokiwami' were the most obvious during deacclimation, with the exception of April 2012. The expression patterns of PpDhn1 and PpDhn3 showed parallel fluctuations in cold hardiness in the four cultivars, whereas PpDhn2 did not show any seasonal changes in any of the cultivars.

No abstract

In order to obtain the basic data that could be used to evaluate the harvest time of new hardy kiwifruit cultivars (Actinidia arguta 'Saehan', 'Daesung' and 'Chilbo'), the seasonal fruit quality and ripening characteristics of hardy kiwifruit were investigated. Fruit sizes of 'Saehan', 'Daesung' and 'Chilbo' were increased from full bloom to 66 days, 85 days and 78 days, respectively. The growth curve of developing fruit of three cultivars showed double sigmoid. As a result of correlation analysis, the seed number per fruit showed a significant positive correlation with fruit weight (r = 0.94~0.97, p<0.01). Fruit length, width, thickness, weight, soluble solid content and titratable acidity were significantly different among the cultivars. Titratable acidity was increased from full bloom to harvest time and the titratable acidity of 'Saehan', 'Daesung' and 'Chilbo' were 1.77%, 1.22% and 1.37% on havest time, respectively. Optimal harvest time of 'Saehan' was 108 days (23 Sep.) after full bloom, those of 'Daesung' and 'Chilbo' were 92 (9 Sep.) days after full bloom.