Epigenetics and Proteomics Studies of Drought Tolerance in Hall’s Grass

Plants are susceptible to different environmental factors (abiotic and biotic) which limit their growth and reproduction. To adapt the condition, they employ various sophisticated ways to adverse environmental situations without distressing their survival of proper growth, reproductive success and overall development. Abiotic environmental factors can distract the total proteome composition of a plant. To understand this, a complex network of regulating gene expression at molecular level (transcriptional and post-transcriptional) is required, including epigenetic framework. PRMT1 belongs to the family of methyltransferases (Arginine specific) which leads to the formation of an epigenetic transcriptional memory. ChIP-Seq was done using the Next-Gen sequencing platform. Both HiSeq and MiSeq yielded more than 44 million raw reads per samples. This represents about 93% of the mapping ratio for the genome of Hall’s grass (Panicum hallii, panhal2). This information was tracked using a browser that provided all identified peaks. Roughly 1300 to 34746 peaks were observed in the annotated gene regions. Some regions were enriched above the background. Fourteen common and 91 upregulated broad and narrow peaks were identified from the ChIP which sequenced the control and drought treated samples. After epigenetic modifications in Panicum hallii, some locations of the genome were enriched with high protein fold enrichment values. This confirmed that the presense of DNA-protein binding site occurred through methylase enzymes. Mass Spectrometry Analysis from leaf nuclear proteomic study identified 4480 proteins from Panicum hallii after drought stress. Among the identified proteomes, 2983 were proteins of 2 or more peptides and 96 (2.14%) proteins were significantly changed proteins found from the quantitative analysis. Several identified nuclear proteins were found to be increased with drought and thought to give protection after stress condition. Proteomic associated molecular studies to drought condition opens some important candidate genes or proteins to be used in understanding drought tolerance mechanism. Identification of 227 sequence specific motifs and Proteomics analysis will facilitate the molecular study of P. hallii. This information produced by ChIP-seq is expected to produce a framework for association illustrating the transcriptional control of gene expression in Panicum hallii. Data are available at NCBI SRA database under the accession PRJNA553526

EVALUATION OF THE EFFECT OF ELEVATED HYDROSTATIC PRESSURE FOR INACTIVATION OF LISTERIA MONOCYTOGENES.

The growth and survival of food borne pathogens in the food processing industries is one of the most important concerns affecting the health safety of consumers by causing infections and food spoilage. Listeria monocytogenes is recognized as a widespread foodborne pathogenic species that causes Listeriosis outbreaks associated with a variety of food products. There are only a limited number of studies available demonstrating the synergistic efficacy of combining different control mechanisms against food borne pathogens (such as L. monocytogenes), which could increase the food safety and the shelf life of food products. The current study investigated L. monocytogenes inactivation using high-pressure processing (HPP) only and a combination of HPP and caprylic acid. In this study we used a constant inoculum level 10^7 CFU/ml, exposed to different pressure intensities (200 - 500 MPa), with or without the addition of 0.1% caprylic acid, for 0, 3, and 5 minutes at 4℃. Exposure to 400 MPa at 4℃ without caprylic acid resulted in about a 2.0 log CFU/ml reduction in L. monocytogenes, while exposure to 500 MPa resulted in 3 log CFU/ml reduction. Exposure to 400 and 500 MPa at 4℃ with the addition of 0.1% caprylic acid did not show any significant differences in the log CFU/ml reduction compared to treatments without synergism. Treatments conducted at less than 400 MPa were less effective at the decontamination of L. monocytogenes. Generally, the longer the sample was exposed to elevated hydrostatic pressure, the more effective the decontamination effort was. This was more apparent at treatments of 400 MPa or greater. The results of this experiment could be important to the future of food decontamination protocols as it shows an effective alternative to the popular methods currently utilized in food safety management systems working to mitigate the burden of listeriosis