Carrot (Daucus carota) is an important vegetable crop, providing over 30% of the pro-vitamin A carotenoids in the human diet in the United States. As a major source of these nutriceutical compounds, research efforts have been directed to the regulation of this complex metabolic pathway. This project focused on evaluating gene expression, sequence changes and genetic mapping as it relates to the accumulation of the carotenoid pigments alpha-carotene, beta-carotene, xanthophylls, and lutein. Real-time quantitative PCR (RT-qPCR) was used to determine the level of expression of genes in the carotenoid biosynthesis pathway in different carrot culitvars. Two genes, phytoene synthase 1 (PSY1) and phytoene synthase 2 (PSY2) were found to be expressed at significantly higher levels in orange and dark orange carrot cultivars, whereas the pale orange rp "reduced pigment" mutant exhibited reduced phytoene desaturase (PDS) expression. DNA sequence analysis of putative promoter and coding regions of both PSY1 and PSY2 has identified sequence polymorphisms and large deletions were identified in the putative promoter of PSY2 in the dark orange cultivar B2327. Simple sequence repeat markers (SSRs) were used to create a genetic map from an F2 population segregating for the rp mutation. HPLC (high performance liquid chromatography) analyses of the carotenoids of carrot leaf tissue demonstrated xanthophylls and beta-carotene as the carotenoids present in all carrots, but significantly higher levels of alpha-carotene was identified in carrot germplasm with orange and dark orange storage roots. Chlorophyll fluorescence analysis identified genotype specific variation in photosystem II efficiency, significantly impacted by the time of harvest. To identify new candidate genes involved in carotenoid accumulation in carrot storage root, microarray analysis of sibling white and orange inbred lines from a cross of orange X white carrots was completed. Expression of three genes involved in photosynthesis was significantly higher in the orange rooted carrot germplasm. To examine the role that chromoplast biosynthesis may have in the accumulation of carotenoid pigments, the ratio of nuclear to plastid genome was analyzed in carrot germplasm with differing levels of pigmentation.

This paper provides guidelines for new high-throughput screening methods – both phenotypic and genotypic – to enable the detection of rare mutant traits, and reviews techniques for increasing the efficiency of crop mutation breeding.

This is the only book of its kind to provide an overview of the science of flavonoids in plants.

This comprehensive treatise provides a systemic and insightful overview of current advances in the biosynthetic genomics/genetics and preventive dietetics of carotenoids, flavonoids and betalains, from a general perspective, and in specific fruits and vegetables as well. Genomics/genetics focuses on what and how enzymatic and regulatory genes are involved in pigment biosynthesis. Dietetics emphasizes how these pigments contribute nutritional/medical benefits to health, prevent diseases, and act as potential nutraceuticals in the diet. The goal is to provide research scientists, nutrition specialists, healthy food advocates, students, and rainbow food (fruit and vegetable) lovers with an integrated resource on the biosynthetic and dietetic mechanisms of these pigments.

In recent years there has been an unprecedented expansion of knowledge about anthocyanins pigments. Indeed, the molecular genetic control of anthocyanins biosynthesis is now one of the best understood of all secondary metabolic pathways. There have also been substantial improvements in analytical technology that have led to the discovery of novel anthocyanin compounds. Armed with this knowledge and the tools for genetic engineering, plant breeders are now introducing vibrant new colors into horticultural crops. The food industry has also benefited from the resurgence of interest in anthocyanins. A greater understanding of the chemistry of these pigments has led to improved methods for stabilizing the color of anthocyanins extracts, so that they are more useful as food colorings. Methods for the bulk production of anthocyanins from cell cultures have been optimized for this purpose. Possible benefits to human health from the ingestion of anthocyanin-rich foods have also been a major feature of the recent scientific literature. Anthocyanins are remarkably potent antioxidants, and their ingestion has been postulated to stave off the effects of oxidative stress. These pigments, especially in conjunction with other flavonoids, have been associated with reductions in the incidence and severity of many other non-infectious diseases, including diabetes, cardiovascular disease and certain cancers. An industry is developing around anthocyanins as nutritional supplements. Finally, there has been significant progress in our understanding of the benefits of anthocyanins to plants themselves. Originally considered an extravagance without a purpose, anthocyanins are now implicated in multifarious vital functions. These include the attraction of pollinators and frugivores, aposematic defense from herbivores, and protection from environmental stressors such as strong light, UVB, drought, and free radical attacks. Anthocyanins are evidently highly versatile, and enormously useful to plants. This book covers all aspects of the biosynthesis and function of anthocyanins (and related compounds such as proanthocyanidins) in plants, and their applications in agriculture, food products, and human health. Featured areas include their relevance to: * Plant stress * Flower and fruit color * Human health * Wine quality and health attributes * Food colorants and ingredients * Cell culture production systems * The pastoral sector

Genome Editing in Plants: Principles and Applications addresses the information of genome editing starting from principles and historical aspects to the latest advancements in the field. As genome-editing technology has emerged as promising and cutting edge, researchers around the world have started producing original research outputs, which have significantly improved our current understanding and potential of this technology. The initial chapters of this book describe different genome-editing tools as well as their principles and applications. Other chapters are dedicated to the present status and future applications of genome-editing techniques in various crop improvement programmes. Some of the advanced applications of CRISPR/Cas tools, such as base editing and RNA detection, along with regulatory aspects of genome-edited crops are described in detail. This book serves as a valuable resource to researchers in the field of crop improvement; graduate and postgraduate students engaged in plant molecular biology and biotechnology; academicians; and policy makers. Key Features: Addresses topics associated with historical development and principles of genome-editing technology Addresses basic mechanisms operating under each genome-editing technology Addresses its application in plants to design crops as per the current and future demands Addresses the regulatory mechanisms of genome-edited crops