Changes in Plant Gene Expression in Response to Gold Nanoparticles and Gold Ions

Plants have been struggled by changing environmental conditions for millions of years. Fortunately, plants have the ability to accommodate it by fine-tuning itself. Genes, which are commonly known as functional unit of heredity in books, are secret weapons of plants that are always ready to be used for any changing circumstances. These DNA-level units open, close, and change their expressions to finalise a protein that survives the plant. Recently, nanoparticle (NP) synthesis and application to various fields such as agriculture, biomedicine, and industry, is a new avenue for science and a pioneering topic for researchers. Although there are industrial ways to synthsise NPs, biological synthesis, which is done by bacteria, viruses, fungi and some algae, is the the most eco-friendly and reasonably priced way to obtain. The synthesised NPs are employed in numerous fields including medicine (metal–organic cages), pharmacology (nanocarriers), agriculture (remediation of soil), food industry (preservatives and packaging), heavy industry (automotive and petrol), cosmetics, chemical industry (coatings, paints, water purification, energy source in batteries and supercapacitors). The list is being extended by each scientific article published. However, each NP used whether produced by chemical or biomaterial-based, has an affect on organisms. The present chapter focuses on how plants respond to Au-NPs on gene level by criticising recent studies and discussing prospects of how can human benefit NPs to “design” better plants to increase yield and be tolerant to harsh environmental conditions.