Cold Hardiness of Primary Buds of Wine and Table Grape Cultivars in Poland

The aim of this study was to compare the cold resistance of grapevine cultivars in field conditions. Following the winters of 2016/2017 and 2017/2018, an assessment of frost damage was carried out on the vines of 42 wine cultivars and 45 table grape cultivars grown in central Poland (Skierniewice, latitude 51.9627 N, longitude 20.1666 E). The minimum temperature for each of the two winters was recorded on 2017-01-07 (-20.9°C) and on 2018-02-27 (-20.1°C). Among the assessed cultivars, 19 (13 wine grape cultivars and six table grape cultivars) belonged to V. vinifera species and 68 were inter- or inter-intraspecific hybrids.  Cultivars were divided into five classes of different frost tolerance, with information on the proportion of primary buds frozen given in the brackets: very resistant (below 1.9%), resistant (2% to 24.9%), medium susceptible (2% to 74.9%), susceptible (75% to 95.9%) and very susceptible (above 96%). The number of wine and table grape cultivars in particular classes (mean for two winters) was as follows: very resistant– 20 (wine) and 10 (table), resistant – 15 and 13, medium susceptible – six and 20, susceptible – one and two. Both the V. vinifera cultivars and the interspecific hybrids were highly diversified in terms of frosttolerance. In most cultivars, the number of frozen buds after the winter of 2016/2017 was greater than after the winter of 2017/2018. Among V. vinifera, ‘Riesling’, ‘Pinot Noir’, ‘Chasselas Dore’ (reference) and ‘Tauberschwarz’, ‘Veltliner Frührot’ (‘Fruehroter Malvasier’), ‘Turan’, ‘Domina’, ‘Tressot Panache’, ‘Blue from Tychy’, and ‘Irsai Oliver’ were very resistant or resistant. Other cultivars of V. vinifera were medium susceptible or susceptible

Diversity of Arbuscular Mycorrhizal Fungi in the Rhizosphere of Solaris and Regent Grapevine Plants Treated with Bioproducts

The aim of this study was to identify the spores of arbuscular mycorrhizal fungi (AMF) in the rhizosphere of Solaris and Regent grapevine plants grafted onto SO4 rootstock and treated with bioproducts. The bioproducts Ausuma, Bioilsa, manure and BF Ekomix were tested and applied on their own, or combined with standard mineral fertilisation (NPK). The applied bioproducts contributed to an increase in the number of species of mycorrhizal fungi in the rhizosphere soil of the grapevines. The most frequently occurring AMF species was Claroideoglomus claroideum. Biopreparation BF Ekomix was a promisingagent for increasing the number of AMF spores in the rhizosphere of Regent grapevines. In the rhizosphere of Solaris, a positive influence on the number of spores occurred after the application of Bioilsa

Physiological Response of Three Grapevine Cultivars Grown In North-Western Poland to Mycorrhizal Fungi

West Pomerania (Poland) is located near the northern boundary of the range of viticulture (the coldest zone A). Unfavourable weather conditions can pose a serious threat to the cultivated vines. One of the treatments used to increase the tolerance of plants to abiotic and biotic stresses is inoculation with symbiotic soil microorganisms. This paper focuses on the influence of mycorrhization on the changes in soil microbiology, the degree of colonization of roots by mycorrhizal fungi, and on selected physiologicalparameters of three grapevine cultivars (‘Pinot Noir’ on SO4 rootstock, ‘Regent’ on 5BB rootstock, and ‘Rondo’ on 125AA rootstock). The applied inoculation had a stimulating effect on the colonization of roots by arbuscular mycorrhizal (AM) fungi, as evidenced by higher mycorrhizal frequency and intensity in the mycorrhized plants. The mycorrhizal treatment increased the intensity of CO2 assimilation and transpiration. Mycorrhization reduced the efficiency of photosynthetic water use and increased stomatal conductance for water in the grapevines tested. The mycorrhizal treatment did not affect the concentration of assimilation pigments in vine leaves. The mycorrhization of grapevines had no effect on the values of initial fluorescence, maximum fluorescence, the maximum potential efficiency of photochemical reaction in PS II, the size of the pool of reduced electron acceptors in PS II, nor on the value of the PS II vitality index

Targeting SHP2 phosphatase in breast cancer overcomes RTK-mediated resistance to PI3K inhibitors

BACKGROUND: PI3K signaling is frequently activated in breast cancer and is targeted by PI3K inhibitors. However, resistance of tumor cells to PI3K inhibition, often mediated by activated receptor tyrosine kinases, is commonly observed and reduces the potency of PI3K inhibitors. Therefore, new treatment strategies to overcome resistance to PI3K inhibitors are urgently needed to boost their efficacy. The phosphatase SHP2, which plays a crucial role in mediating signal transduction between receptor tyrosine kinases and both the PI3K and MAPK pathways, is a potential target for combination treatment. METHODS: We tested combinations of PI3K and SHP2 inhibitors in several experimental breast cancer models that are resistant to PI3K inhibition. Using cell culturing, biochemical and genetic approaches, we evaluated tumor cell proliferation and signaling output in cells treated with PI3K and SHP2 inhibitors. RESULTS: Combination treatment with PI3K and SHP2 inhibitors counteracted both acquired and intrinsic breast cancer cell resistance to PI3K inhibition that is mediated by activated receptor tyrosine kinases. Dual PI3K and SHP2 inhibition blocked proliferation and led to sustained inactivation of PI3K and MAPK signaling, where resistant cells rapidly re-activated these pathways upon PI3K inhibitor monotreatment. In addition, we demonstrate that overexpression of SHP2 induced resistance to PI3K inhibition, and that SHP2 was frequently activated during the development of PI3K inhibitor resistance after prolonged treatment of sensitive cells. CONCLUSIONS: Our results highlight the importance of SHP2 as a player in resistance to PI3K inhibitors. Combination treatment with PI3K and SHP2 inhibitors could pave the way for significant improvements in therapies for breast cancer

Mutant p53 as a guardian of the cancer cell

Forty years of research have established that the p53 tumor suppressor provides a major barrier to neoplastic transformation and tumor progression by its unique ability to act as an extremely sensitive collector of stress inputs, and to coordinate a complex framework of diverse effector pathways and processes that protect cellular homeostasis and genome stability. Missense mutations in the TP53 gene are extremely widespread in human cancers and give rise to mutant p53 proteins that lose tumor suppressive activities, and some of which exert trans-dominant repression over the wild-type counterpart. Cancer cells acquire selective advantages by retaining mutant forms of the protein, which radically subvert the nature of the p53 pathway by promoting invasion, metastasis and chemoresistance. In this review, we consider available evidence suggesting that mutant p53 proteins can favor cancer cell survival and tumor progression by acting as homeostatic factors that sense and protect cancer cells from transformation-related stress stimuli, including DNA lesions, oxidative and proteotoxic stress, metabolic inbalance, interaction with the tumor microenvironment, and the immune system. These activities of mutant p53 may explain cancer cell addiction to this particular oncogene, and their study may disclose tumor vulnerabilities and synthetic lethalities that could be exploited for hitting tumors bearing missense TP53 mutations

Assessment of genetic diversity and relationships among grapevine cultivars originating in Central and Eastern Europe and North America using ISSR markers

The study shows genetic diversity of 38 Vitis vinifera L. cultivars and hybrids originating in North America and Europe, including cultivars selected in Poland, which have not been characterized with the use of DNA markers yet. The agrobiological features of the genotypes selected for testing indicate that they may be useful for the breeding of new cultivars and grape production. The use of 12 ISSR primers allowed to obtain 94.4% of polymorphism. The polymorphic information content (PIC) value was high and varied between 0.829 and 0.953 with an average of 0.897. The resolving power (Rp) ranged between 3.678 and 8.892 with an average of 6.347. Primers UBC 809, UBC 810, UBC 812, UBC 855, UBC 891 and UBC 810 were found to be highly effective (informative). Similarity coefficient ranged between 0.167 and 1.0, which indicates high degree of diversity of tested grape cultivars. Tested cultivars were grouped in 3 main clusters; one of them was further divided into 6 subclusters. ‘Pannonia Kincse’ and ‘Danmarpa Polonia’ were not differentiated. Phenotypic differences among those two cultivars suggest that ‘Danmarpa Polonia’ might be a clone of ‘Pannonia Kincse’ and other molecular techniques must be used to differentiate them. Morphological and agrobiological characters of cultivars support the results obtained by ISSR markers

On stationary Markov chains and independent random variables

Two new proofs are given for the fact that a stationary, irreducible, aperiodic Markov chain (Xn N = ..., -1,0,1,2...) with denumerable state space has a representation of the form X'n=g(Un-1, Un-2,...), where g is a measurable function, (Un, N= ..., -1,0,1,2,...) a sequence of independent random variables uniformly distributed on (0,1), and (X'n) has the same probability law as (Xn).Markov chain representation i.i.d. random variables