Use of Different Promoters in Transgenic Plant Development: Current Challenges and Future Perspectives

Genetic transformation aims to introduce gene with desirable trait into plant for a particular purpose and geographical location(s). According to need, the gene is transferred with specific promoter to obligate its expression either all the time or at particular time and tissue. A variety of diverse promoters are convenient that regulate the degree of expression of a transgene, obtained from various sources. The specificity of a promoter is crucial in controlling expression of transgene in target tissue or in whole plant. Among the different plant promoters, the constitutive promoter, like CaMV 35S is most commonly used in plant genetic transformation particularly in dicots. However, the risk involved in the use of constitutive promoter is its release into the environment through horizontal gene transfer causing adverse effects on non-target organisms and eco-system. Therefore, the importance of inducible promoter is to increase the expression of genes in a particular tissue or at specific developmental stage(s). Genetic engineered crops sometimes raise problem to biosafety concern when selectable marker gene is used that causes adverse effects on organisms. So, it is the responsibility of researchers to develop a baseline for the acceptance of risk free transgenic crop to the consumers.