Growth modulation by nitric oxide donor sodium nitroprusside in in vitro plant tissue cultures – A review

The plant tissue culture system is one of the important facets of plant biology and various biotechnological applications and great advances have been coupled with the plant cell, tissue, and organ cultures. Technological advances in in vitro systems have paved the way for great strides in crop improvement, germplasm conservation, commercial-scale micropropagation, genetic manipulation, and metabolite production. Sodium nitroprusside (SNP), a nitric oxide donor has recently been used most widely in various plant tissue culture and propagation systems owing to its growth-promoting activities. The cellular, biochemical and molecular mechanism by which SNP brings about growth, differentiation, and development in plants is not well understood. However, in the past decade, the use of SNP as a novel molecule to promote plant growth and development has opened up new avenues in in vitro plant biology research resulting in evolving defined protocols for various in vitro responses. Positive effects of SNP have been reported concerning callus induction, organogenesis, somatic embryogenesis, genetic transformation, and resistance to biotic and abiotic stresses. This review highlights the application of SNP as a potent plant growth modulator in various plant tissue culture protocols to work out desirable in vitro responses.