Advances in research on the carrot,an important root vegetable in the Apiaceae family

Carrots(Daucus carota L.),among the most important root vegetables in the Apiaceae family,are cultivated worldwide.The storage root is widely utilized due to its richness in carotenoids,anthocyanins,dietary fiber,vitamins and other nutrients.Carrot extracts,which serve as sources of antioxidants,have important functions in preventing many diseases.The biosynthesis,metabolism,and medicinal properties of carotenoids in carrots have been widely studied.Research on hormone regulation in the growth and development of carrots has also been widely performed.Recently,with the development of high-throughput sequencing technology,many efficient tools have been adopted in carrot research.A large amount of sequence data has been produced and applied to improve carrot breeding.A genome editing system based on CRISPR/Cas9 was also constructed for carrot research.In this review,we will briefly summarize the origins,genetic breeding,resistance breeding,genome editing,omics research,hormone regulation,and nutritional composition of carrots.Perspectives about future research work on carrots are also briefly provided.

Morphological characteristics, anatomical structure, and gene expression: novel insights into gibberellin biosynthesis and perception during carrot growth and development

Gibberellins(GAs)are considered potentially important regulators of cell elongation and expansion in plants.Carrot undergoes significant alteration in organ size during its growth and development.However,the molecular mechanisms underlying gibberellin accumulation and perception during carrot growth and development remain unclear.In this study,five stages of carrot growth and development were investigated using morphological and anatomical structural techniques.Gibberellin levels in leaf,petiole,and taproot tissues were also investigated for all five stages.Gibberellin levels in the roots initially increased and then decreased,but these levels were lower than those in the petioles and leaves.Genes involved in gibberellin biosynthesis and signaling were identified from the carrotDB,and their expression was analyzed.All of the genes were evidently responsive to carrot growth and development,and some of them showed tissue-specific expression.The results suggested that gibberellin level may play a vital role in carrot elongation and expansion.The relative transcription levels of gibberellin pathway-related genes may be the main cause of the different bioactive GAs levels,thus exerting influences on gibberellin perception and signals.Carrot growth and development may be regulated by modification of the genes involved in gibberellin biosynthesis,catabolism,and perception.