Helicase: A genetic tool for providing stress tolerance in plants

Abstract

Alteration of stress (abiotic and biotic) constitutes one of the major problems for normal plants health. In the present scenario, new molecular tools are broadly utilized to improve stress tolerance and high-yielding crop plants. Helicases are such molecular proteins that present as one of the largest conserved gene families in eukaryotes, prokaryotes, and plants. All members of this gene family are involved in DNA and RNA metabolism inside the cell which maintains normal cellular functions. Environmental stress broadly reduces the plant's growth and yield which causes severe global food losses. To overcome stress-inducing crop losses, a stress-tolerant trait is required for food security. Helicases are involved in the process of nucleic acid inside the cell and act as potential molecules for abiotic stress tolerance in plants. Both DNA and RNA helicase highly influences the plant's defense mechanism that protects plants from pathogen infection and other stress factors Helicase is the molecular conserved enzyme which classified into six superfamilies from SF1 to SF6. DNA helicase is a protein and acts as a molecular motor. Helicase uses the energy of nucleoside 5′-triphosphate (NTP) to unwinding the energetic stable DNA duplex into single strands. All the DNA helicases have some common properties. Those are nucleic acid binding, hydrolysis, NTP binding, and unwinding of ds DNA in the 3′ to 5′ or 5′ to 3′ direction. DNA helicases are mainly present in plants’ nuclei, mitochondria, and chloroplasts. But recently some researchers found that plant DNA helicases have an important role to develop healthy high yielding plants under stressful environments. Unlike DNA helicase, RNA helicase is a large group of biochemical activities, including RNA duplex unwinding, protein displacement from RNA, and strand annealing. DEAD-box RNA helicases are involved in RNA metabolisms like RNA duplex unwinding, protein displacement from RNA, and strand annealing. In this review, we have summarized and discussed the structure, function, and role of helicases in the stress tolerance of different crops.