Cold Storage of Plant Tissue Cultures – Effect of Sucrose

Explants of normal (non-transformed) carrot (Daucus carota L.) tissue, scorzonera crown gall (Scorzonera hispanica L.) and carrot tissues transformed with Agrobacterium tumefaciens (all cultured in vitro) were planted in little glass jars with 6 cm3 of nutrition media containing 3, 5, 7 or 9% sucrose and maintained at +3 °C for 6, 8, 10 and 12 months. Viability of tissue cultures after cold storage was estimated by the degree of tissue necrosis, per cent of explants exhibiting growth resumption and intensity of the resumpted growth. Little or no growth was observed during cold storage of scorzonera and normal carrot tissues, whereas transformed carrot tissues showed significant growth. Dry matter content of tissues increased with an increase of sucrose concentration in the medium and failed to change during cold storage of scorzonera and normal carrot tissues. The dry matter content of the transformed carrot tissues fell down during cold storage due to the increase of fresh weight. The viability of all tissue cultures was preserved better and for a longer time with 7% sucrose, than with 3, 5 and 9%. Transformed carrot and tobacco callus tissues preserved cell viability better than non-transformed ones. Cycles consisting from long subcultures (several months) at 3 °C interrupted by short subcultures (several weeks) at 26 °C were applied in order to storage of tissue cultures for several years

Implications of Plants Genetic Transformation Assessed by Geneticist, Biochemist and Physiologist

Transgenic plants creation methodology developed for several decades has gained significant advances. However, problems of unanticipated effects of transgenosis, stability of GMO characteristics and establishing criteria of their safety evaluation remain unresolved. The analysis of different approaches to assessing the impact of plant genetic transformation is presented. It is concluded that the profound studies on the physiology of plant-agrobacterial symbiosis as a methodological basis of plants genetic engineering can answer many unresolved issues of genetic engineering

Physiological Consequences of Genetic Transformation: Result of Target Gene Expression or Stress Reaction?

The transgenic and non-transgenic tobacco cell cultures were analyzed for resistance to abiotic and biotic stress. The different physiological reaction of cell culture depending on T-DNA structure (or transgen structure) was observed. The cell culture transformed by disarmed Agrobacterium tumefaciense A699 with pCNL 65 nptII demonstrated the same stress-resistance as non-transgenic control cell culture. The cell culture transformed by Agrobacterium tumefaciense LBA 4400 pBiCaMV nptII + hsp101 showed a raised stress-resistance to high temperature, high KF concentration, and to the action of Clavibacter michiganensis ssp sepidonicus. Obviously, the expression of transferred arabodopsis gene hsp101 provides protection properties of transgenic cell culture under the influence of various stress factors. Moreover, that agrobacterial transformation as previous stress-factor is supposed to make a contribution to formation of transgenic cell culture cross-resistance

Lynch Syndrome Germline Mutations in Breast Cancer: Next Generation Sequencing Case-Control Study of 1,263 Participants

© Copyright © 2020 Nikitin, Chudakova, Enikeev, Sakaeva, Druzhkov, Shigapova, Brovkina, Shagimardanova, Gusev and Gordiev. Genome instability—the increased tendency of acquiring mutations in the genome and ability of a cell to tolerate high mutation burden—is one of the drivers of cancer. Genome instability results from many causes including defects in DNA repair systems. Previously, it has been shown that germline pathogenic mutations in DNA Mismatch Repair (MMR) pathway cause cancer-predisposing Lynch Syndrome. We proposed that Lynch Syndrome-related germline mutations (LS-mutations) are associated with breast cancer (BC). In this study, we performed Targeted Next-Generation Sequencing of MMR pathway genes MLH1, MSH2, MSH6, EPCAM, and PMS2 in a cohort of 711 patients with hereditary BC, 60 patients with sporadic BC, and 492 healthy donors. Sixty-nine patients (9.7%) with hereditary BC harbored at least one germline mutation in the MMR pathway genes, of them 32 patients (4.5%) harbored mutations in MMR pathway genes which we define as pathogenic or likely pathogenic, and of them 26 patients (3.6%) did not have any pathogenic mutations in DDR pathway genes, compared to two mutations in MMR pathway genes (0.4%) detected in a group of 492 healthy donors [p = 0.00013, OR = 8.9 (CI 95% 2.2–78.4)]. Our study demonstrates that LS-mutations are present in patients with hereditary BC more frequently than in healthy donors, and that there is an association of hereditary BC and mutations c.1321G>A in MLH1, c.260C>G and c.2178G>C in MSH2, c.3217C>T in MSH6, c.1268C>G and c.86G>C in PMS2 genes. This finding provides a rationale for including pathogenic LS-mutations into genetic counseling tests for patients with hereditary BC