RESUMEN
The LED Blue Light (LBL) (450 nm) effect on hormones levels and on jasmonates (JAs) metabolism in oranges was investigated. The quantum flux (2 days, 60 µmol m-2. s-1) was chosen for its efficacy in reducing postharvest rot caused by this crop's main postharvest phytopathogenic fungus (Penicillium digitatum). The analysis of abscisic (ABA), salicylic (SA) and indole-3-acetic (IAA) acids, and of JAs-related metabolites, revealed that LBL modifies all studied metabolites and had major effects on JAs levels, mainly on jasmonic acid (JA) and its precursor cis-(+)-12-oxo-phytodienoic acid (OPDA). This agrees with the up-regulation of the genes participating in their synthesis. Results highlight the relevance of CsLOX1 and CsLOX5, and the contribution of CsAOC3, in the LBL-induced OPDA biosynthesis, whereas CsOPR2, CsACX1 and CsACX3 would play a part in the synthesis of JA from OPDA. Data also suggest that the applied LBL quantum flux favors fruit JA perception by increasing the expression of the coronatine insensitive 1 (COI1) receptor; and signaling by down-regulating abundant CsJAZ negative regulators. Differences in OPDA and JA between the LBL-treated oranges and their control fruit left in the dark disappeared after shifting the LBL-treated oranges to darkness for 3 more days. However, the LBL and darkness combination slightly increased IAA and SA contents.
Asunto(s)
Ácido Abscísico , Ciclopentanos , Frutas , Luz , Oxilipinas , Reguladores del Crecimiento de las Plantas , Oxilipinas/metabolismo , Ciclopentanos/metabolismo , Reguladores del Crecimiento de las Plantas/metabolismo , Frutas/metabolismo , Frutas/efectos de la radiación , Ácido Abscísico/metabolismo , Citrus/metabolismo , Citrus/microbiología , Ácidos Indolacéticos/metabolismo , Regulación de la Expresión Génica de las Plantas , Ácido Salicílico/metabolismo , Proteínas de Plantas/metabolismo , Proteínas de Plantas/genética , Ácidos Grasos Insaturados/metabolismo , Luz AzulRESUMEN
Copper (Cu) is an essential micronutrient for plants because it functions as a redox-active cofactor in vital processes inside the cells. Arable lands are often deficient in micronutrient contents and require the application of enriched fertilisers, whose overuse poses a high risk for human health, the environment and the food safety. Here, we aimed to decipher the effects of Cu deficiency during fruit growth on Cu and other micronutrients contents and on the fruit nutritional value and quality of tomato, the most consumed fruit worldwide, throughout the maturation process. Changes in the contents of important micronutrients for fruit physiology and human health, such as Fe and Mn, occurred in response to Cu deficient growing conditions at different fruit ripening stages, while lower Cu levels were detected in those fruit along the whole maturation process. Cu deficiency delayed changes in lycopene content and fruit colour, but increased acidity, and advanced the rise in antioxidant capacity and vitamin C content during fruit colour change from green to light red in the Moneymaker tomato; although this time lag eventually caught up in the most mature fruit stage. Cu deficiency also increased total phenolic and flavonoid contents only in green fruit.
Asunto(s)
Solanum lycopersicum , Humanos , Frutas , Cobre , Licopeno , Valor Nutritivo , MicronutrientesRESUMEN
Copper (Cu) plays a key role as cofactor in the plant proteins participating in essential cellular processes, such as electron transport and free radical scavenging. Despite high-affinity Cu transporters (COPTs) being key participants in Cu homeostasis maintenance, very little is known about COPTs in tomato (Solanum lycopersicum) even though it is the most consumed fruit worldwide and this crop is susceptible to suboptimal Cu conditions. In this study, a six-member family of COPT (SlCOPT1-6) was identified and characterized. SlCOPTs have a conserved architecture consisting of three transmembrane domains and ß-strains. However, the presence of essential methionine residues, a methionine-enriched amino-terminal region, an Mx3Mx12Gx3G Cu-binding motif and a cysteine rich carboxy-terminal region, all required for their functionality, is more variable among members. Accordingly, functional complementation assays in yeast indicate that SlCOPT1 and SlCOPT2 are able to transport Cu inside the cell, while SlCOPT3 and SlCOPT5 are only partially functional. In addition, protein interaction network analyses reveal the connection between SlCOPTs and Cu PIB-type ATPases, other metal transporters, and proteins related to the peroxisome. Gene expression analyses uncover organ-dependency, fruit vasculature tissue specialization and ripening-dependent gene expression profiles, as well as different response to Cu deficiency or toxicity in an organ-dependent manner.