Embryogenic calli explants and silicon carbide whisker-mediated transformation of cotton (Gossypium hirsutum L.)

Abstract

Rapid growth in the genetic transformation of plants is the outcome of versatile transformation methods, explant nature, and media regimes. Modern biotechnologists have now a toolkit embraced with different plant transformation methods to generate specific and targeted genetic variation for performance improvement of crop plants. Genetic information are created by proper custom synthesis/amplification of DNA sequences from natural sources, modification during gene cloning, and choice of regulatory sequences and delivered to plants via different plant transformation techniques. Cotton is known by different names like king of fiber crops, white gold, etc., due to its socioeconomic involvement in society livelihood. So cotton is the host of several transgenes delivered for the purpose of trait development of improvement outcompeting its wild counterparts. At present most of the cotton adopted by farmers is biotech and contributes significantly in meeting farmers and industry demands. It is the versatile nature of cotton that it has been subjected to different genetic transformation methods to provide the breeders with an opportunity to develop alien traits or improve the endogenous gene performance that are very difficult or impossible to develop through conventional breeding methods. Landmark achievements were achieved by expanding explant choice such as calli as explants as it reduces the extent of labor, time, and effort and thereby becoming cost-effective cotton transformation. Cotton calli becomes differentiated into embryogenic and non-embryogenic which requires regular screening, keeping in view texture, color, and growth behavior. Here we describe the calli features which are peculiar in nature when used as explants in a novel physical way of cotton transformation with different genes by using embryogenic calli as continuous source of explants. The dawn of genome editing has opened another horizon in transformation research and development enhancing the scope of cotton transformation.