Zinc

About Zinc:

• It is a silvery blue-grey metal with a relatively low melting and boiling point.
• Both lead & zinc are found to occur together in ore along with other metals like silver and cadmium.
• It is the fourth most widely used metal across the globe, trailing only steel, aluminium and copper. India has self-sufficiency in respect of zinc.
• In India, Rajasthan has the largest reserves/resources of lead–zinc ore, followed by Andhra Pradesh (3.03%), Madhya Pradesh (1.98%), Bihar etc.
• Global reservoirs of Zinc: Australia accounts for 27% of the world's zinc reserves, followed by China (18%), Russia & Mexico (9% each), Peru (8%), Kazakhstan (5%), USA (4%), etc.
• Uses:
  • The largest consumer of zinc is the Galvanising Industry. Owing to its corrosion resistance in varied types of environments, zinc is used for protecting steel by way of galvanizing.
  • Large quantities of zinc are used to produce die-castings, which are important in the automobile, electrical and hardware industries.
  • Zinc oxide is widely used to manufacture many products such as paints, rubber,etc.
• Biological role
• • It is a trace mineral, meaning that the body only needs small amounts, and yet it is necessary for almost 100 enzymes to carry out vital chemical reactions.
  • It is a major player in the creation of DNA, the growth of cells, building proteins, healing of damaged tissue, and supporting a healthy immune system.

Key findings

• It found that zinc in plants aids in nitrogen fixation, a process where atmospheric nitrogen is converted into ammonia, an essential nutrient for plants. 
  • Legume crops form a symbiotic relationship with rhizobia, a bacteria that fixes atmospheric nitrogen in root nodules. 
  • However, these nodules are sensitive to environmental factors such as temperature, drought, flooding, soil salinity and high soil nitrogen levels.
• Another vital finding of this study is the identification of a crucial transcription factor that controls nodule breakdown when soil nitrogen levels are high. 
• The researchers discovered that legumes also use zinc as a secondary signal to integrate environmental factors and regulate nitrogen fixation efficiency. The mechanism works due to a transcriptional regulator called Fixation Under Nitrate (FUN).
• FUN is inactivated by zinc through the formation of large filament structures, which are dismantled to release active FUN when zinc levels are low.