Submitted to: Biotech Crops: Concepts, Construction, Contribution and Concerns
Publication Type: Book / Chapter
Publication Acceptance Date: 4/2/2009
Publication Date: 3/2/2010
Citation: Handa, A.K., Srivastava, A., Deng, Z., Gaffe, J., Arora, A., Tiznado-Hernandez, M., Goyal, R., Malladi, A., Negi, P., Mattoo, A.K. 2010. Biotechnological interventions to improve plant developmental traits. In: Kole, C., Michler, C.H., Abbott, A.G., Hall, T.C., editors. Transgenic Crop Plants. Heidelberg, Germany: Springer-Verlag. p. 199-248. Interpretive Summary: Unprecedented progress during the last three decades in our understanding of principles of a living cell, particularly the identification of genes and signaling pathways involved in cell differentiation and organ development, has brought us a broader insight into plant biological processes. Technological advancements are revealing new and fundamental knowledge at the molecular and cellular levels, knowledge that is critical towards achieving the goal of precision-based crop improvement. Modern-day genetic engineering and biotechnology have emerged as promising precision-based technologies for boosting food production in the world and introducing desirable traits such as nutritional enhancement and disease and pest resistance, both important components of agricultural sustainability. Achieving results that benefit the world will depend on the success of applying new knowledge to real-world field scenarios. This is an invited chapter for a text book and summarizes recent literature on the molecular and genetic basis of plant developmental processes which provide a road map for understanding the complex interactions that regulate desirable plant traits. We report how this knowledge is enabling scientists to search for regulatory genes that can be manipulated to enhance desirable developmental traits in agronomical and horticultural crops. This review will be of interest to plant biologists and agriculturists interested in exploring developmental programs that can be genetically modified to introduce desirable traits into crop plants.
Technical Abstract: Developmental traits are coordinated at various levels in a plant and involve organ to organ communications via long distance signaling processes that integrate transcription, hormonal action and environmental cues. Thus, plant architecture, root-soil-microbe interactions, flowering, fruit (and seed) development, and fruit ripening (and seed germination) are highly regulated genetic programs that are also impacted by processes such as organ abscission, organ senescence (and ripening), and programmed cell death (PCD). We note that below-ground processes provide the anchor for a healthy and robust plant but in this chapter we have focused on the above-ground plant processes, bringing together information on the genes and biotechnological applications that can potentially affect production and quality of crop plants.Details on the interactions between hormones, environment and physiology are being unraveled and have begun to reveal how differentially mediated progression of various processes regulate the life span of plants. The challenge is to identify a hierarchy of regulators or a specific pattern of events that control desirable attributes and then genetically modify critical and beneficial processes without negatively impacting other beneficial attributes in crop plants. Thus far, studies on transgenic plants and effectiveness of a gene construct have reinforced the advantage of using tissue-specific and regulatable promoters to tightly conrol the expression of introduced transgene and avoid affecting non-targeted developmental processes. Thus, the need is for identifying and characterizing tissue-specific promoters and promoter elements that control both tissue specificity and the level of expression of the introduced transgene. We also need to develop transgenic plants particularly suited to grow well in eco-friendly, sustainable agricultural systems that have minimal reliance on chemical input and synergistically (positively) influence plant metabolism.