NAC Transcription Factors Role in Various Biotic and Abiotic Stresses

NAC transcription factors are considered as main family of transcriptional regulators in plants. NAC gene family members play significant contribution in regulating transcriptional reprogramming in plants related to plant stress response. These proteins possess highly conserved DNA binding domains and play a diverse functions in several plants. NAC gene is related to several stress factors including biotic and abiotic factors. NAC transcription factors controls several interrelated processes and their protein products can function as negative or positive regulators in many cellular processes. These regulatory functions are also controlled by NAC proteins such as auto and cross regulation. These regulatory proteins are regarded as a central regulator for the interaction of phytohormones in various stress signaling pathways. This review highlights the role of NAC transcription factors in modulating gene expression and their role in various biotic and abiotic stress tolerance in plants.

Exploration of Antimicrobial Perspective of Garlic Allium Sativum L. Against Foodborne Pathogens for Bio-Preservation

Garlic (Allium sativum), has been used long in history as a food ingredient and for medicinal purposes. Its strong antimicrobial and antioxidant properties are due to phenolic and sulfur compounds such as allicin. Current study was designed to investigate the phenolic components, antimicrobial potential and bio-preservative effect of two locally grown garlic varieties i.e. Pink Garlic and White Garlic. Garlic after preparatory operations was subjected to extraction with three solvents i.e. 50% ethanol, 50% methanol and water in orbital shaker with additional sonication step. After filtration and concentrating by rotary evaporator the extracts were freeze-dried. Extraction yields were calculated and subsequent testing was done according to planned work. Total phenolic contents of extracts were measured and allicin and phenolic acids were identified through HPLC. Antimicrobial activity against two common food borne pathogens Escherichia coli and Staphylococcus aureus was checked by disc diffusion method and minimum inhibitory concentration (MIC) was calculated. Protection effect of these extracts was checked on bacterial DNA plasmid and inhibition of biofilm formation of the pathogens was also tested. Toxic effects and mutagenic effect of these extracts were studied by hemolytic assay and Ames test, respectively. Finally, the extracts were applied on the pathogen inoculated raw beef and fish samples to measure their possible reduction in the microbial load. Separately, raw beef and fish treated with garlic extracts were stored at refrigeration temperature to check the bio-preservative effect of garlic extracts. The results revealed a non-significant difference in extraction yield of garlic obtained with various treatments. Total phenolic contents ranged from 57.35-86.18 mg/100g of garlic and allicin content ranged from 62.67-425.6- ppm in the extracts. MIC of garlic extracts fell in the range of 25-133.33 mg/mL against both strains. Garlic extracts protected the bacterial DNA plasmid against H2O2 and inhibited the biofilm formation of both bacteria under sub minimal inhibitory concentration. Hemolysis was found 3.84% at 250 mg/mL concentration of garlic and extracts were found to be non-mutagenic. Moreover, garlic extracts when applied to meat, significantly reduced both strains of pathogens as compared to control and maintained the peroxide value of beef and fish during storage of 16 days on refrigeration temperature. It was concluded that garlic extract can significantly reduce the Escherichia coli and Staphylococcus aureus as well as plays role in extending shelf life of beef and fish.