Dr. Paco Romero

Postharvest Pathology, Physiology and Biotechnology Lab., Food Biotechnology Department, Food Chemistry and Technology Institute (IATA-CSIC), Valencia, Spain
Speech Title: Identification of the high affinity copper transporters family in tomato and the effects of copper availability in their regulation

Abstract: Copper (Cu) is a vital micronutrient that acts as a double-edged sword in living beings because it is an essential redox-active cofactor in biological processes but is toxic when in excess. Plants are also sensitive to Cu availability, whose unbalance leads to yield reduction and, in extreme cases, to total crop failure. Since plant nutritional deficiencies or excesses are often transferred to consumers and may ultimately affect human health, we aim to decipher the regulatory mechanisms underlying Cu uptake and distribution in tomato, one of the most important horticultural crops worldwide. Six COPT members (SlCOPT1-6) were found within the Solanum lycopersicum genome (iTAG2.4). In silico analyses indicate that most of the identified proteins have two major transmembrane domains and three beta-sheets in their structure. In addition, all but SlCOPT4 include the Cu-binding domain and the upstream methionine residues necessary for their functionality. Promoter analyses suggest that SlCOPTs might be regulated by Cu and iron availability, biotic and abiotic stresses, tissue specificities and hormonal signals. Expression data reveal that only SlCOPT1, SlCOPT2 and SlCOPT5 are expressed in fruit. While SlCOPT1 and SlCOPT5 are induced early during fruit development and mainly in locular tissue and vasculature, respectively, SlCOPT2 is expressed in later stages of fruit ripening and focused in seed and columella tissues. Protein interaction analyses point a link between SlCOPTs and well-known Cu homeostasis components, the peroxisomal system, other metals transporters and signaling transduction cascades involving protein kinases and phosphatases. Our work provides a first approach to unravel the molecular mechanisms of how Cu availability during preharvest can affect the nutritional value of horticultural products. This knowledge will help to develop biotechnological tools to minimize the use of Cu-based fertilizers and pesticides, to be used for phytoremediation in contaminated environments, and to grow more safety and sustainable food.