ATM engages autodegradation of the E3 ubiquitin ligase COP1 after DNA damage

The ataxia telangiectasia mutated (ATM) protein kinase is a critical component of a DNA-damage response network configured to maintain genomic integrity. The abundance of an essential downstream effecter of this pathway, the tumor suppressor protein p53, is tightly regulated by controlled degradation through COP1 and other E3 ubiquitin ligases, such as MDM2 and Pirh2; however, the signal transduction pathway that regulates the COP1-p53 axis following DNA damage remains enigmatic. We observed that in response to DNA damage, ATM phosphorylated COP1 on Ser(387) and stimulated a rapid autodegradation mechanism. Ionizing radiation triggered an ATM-dependent movement of COP1 from the nucleus to the cytoplasm, and ATM-dependent phosphorylation of COP1 on Ser(387) was both necessary and sufficient to disrupt the COP1-p53 complex and subsequently to abrogate the ubiquitination and degradation of p53. Furthermore, phosphorylation of COP1 on Ser(387) was required to permit p53 to become stabilized and to exert its tumor suppressor properties in response to DNA damage.     

Influence of Rhizophagus spp. and Burkholderia seminalis on the Growth of Tomato (Lycopersicon esculatum) and Bell Pepper (Capsicum annuum) under Drought Stress

Beneficial interactions of arbuscular mycorrhizal fungi (AM Fungi) and plant growth promoting rhizobacteria (PGPR) have an important role in keeping agriculture sustainable. The present study reports the positive effects of AM fungi (Rhizophagus intraradices, Rhizophagus fasciculatum), Burkholderia seminalis and dual inoculation of these two strains on growth of Lycopersicon esculatum and Capsicum annuum plant under drought stress conditions. Each treatment was replicated six times and was arranged in a complete randomized block design. A significant increase in terms of biomass, root length, shoot length, and chlorophyll content was observed with the plants inoculated with these beneficial microorganisms. Accumulation of proline was found to be less in AM fungi inoculated plants suggesting the role of it in mitigating the water stress. A positive correlation between % colonization and chlorophyll content, root length, catalase activity, and guaiacol peroxidase has been observed depicting the importance of the AM fungi in drought tolerance.     

Fatty acids, bioactive lipids and radical scavenging activity of Celastrus paniculatus Willd. seed oil

In the present contribution lipid composition and characteristics of Indian Celastrus paniculatus seed oil were determined. C. paniculatus seeds are a rich source of oil (46%). The amounts of neutral lipids in the oil were the highest, followed by glycolipids and phospholipids. Oleic followed by palmitic and linoleic were the major fatty acids in C. paniculatus seed oil and its lipid classes. C. paniculatus seed oil being characterized by a relatively high amount of phytosterols, wherein the sterol marker was β-sitosterol followed by campesterol and stigmasterol. γ-Tocopherol was the major tocopherol isomer while the rest being α-tocopherol. When C. paniculatus oil and extra virgin olive oil were compared upon their radical scavenging activity (RSA) toward the stable 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical C. paniculatus oil exhibited stronger RSA. In consideration of potential utilization, detailed knowledge on the composition of C. paniculatus oil is of major importance. The diversity of applications to which C. paniculatus oil can be put gives this plant great industrial importance.     

The 18S rDNA gene discriminates between red-listed and unexplored ethnomedicinal species of Myristicaceae restricted to humid tropics of India

A potentially diagnostic 18S rDNA (ribosomal DNA) gene was amplified reliably from red-listed ethnomedicinal species of Myristica and its wild and related genera. Individuals from nine species of Myristicaceae were utilized for the study. The sequences ranged from 1,767 to 1,794 nucleotide (nt) in length. The GC content (%) varied from 52.77 to 51.04. The frequencies (%) of nt were A (23.31), T (23.82), C (24.48) and G (28.39). The alignment of all sequences produced 195/1,516 variable sites and 1,257/1,516 conserved sites. Total numbers of single nucleotide polymorphism (SNP) sites found in the alignment were 146/1,516. Knema andamanica (Warb.) W.J. de Wilde was the most distinct that included 18 variable regions and 15 InDel with 27 SNP sites, specific to this species. The identified regions from nine species of Myristica and its wild and closely related genera were deposited in the GenBank Database (Accession numbers JN228257-JN228265). Comparison of morphological identifications and phylogenetic analysis indicated that the specimens were correctly assigned on the basis of a short stretch of 18S rDNA (~1,600 bp) making this a potentially useful marker for the rapid molecular assignment of an unknown related species also. Significant sequence homology ranging from 72 to 99 % was observed on comparison with 18S rDNA genes of other plants in the public domain. A comparison of intraspecific data information of nine 18S with that of 73 matK and 86 rbcL sequences from GenBank revealed that polymorphism, divergence and conservation is higher in 18S locus for Myristicaceae. Hence these markers may be utilized for phylogenetic analysis, evaluation of species richness during ecological surveys or for environmental assessments. These molecular markers are especially important due to the fact that the species studied are mostly vulnerable and red-listed with limited availability in endangered ecological niches.