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 is endowed with 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 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 environment, 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 in the manufacture of very many products such as paints and 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, growth of cells, building proteins, healing damaged tissue, and supporting a healthy immune system.

Key findings

• It found that zinc in plantsaids 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.

Q1: What is galvanisation?

It is the process of applying a protective zinc coating to iron or steel, to prevent rusting. The most common method is hot dip galvanizing, in which steel sections are submerged in a bath of molten zinc.

Source: Unexpected discovery reveals zinc’s crucial role in making legumes resilient to climate change