New insights about cadmium impacts on tomato: Plant acclimation, nutritional changes, fruit quality and yield

Abstract

Tomato is an important crop worldwide. Cadmium (Cd) concentrations in fruits depend on tomato genotype. This work aimed to study the relation among Cd accumulation, tolerance mechanisms, and fruit features in two tomato cultivars with contrasting tolerance to Cd stress. Tolerant (Yoshimatsu) and sensitive (Tropic Two Orders) plants were grown in control and contaminated soils (0.04 and 3.77 mg/kg Cd, respectively) from the seedling stage to fruit production. Both cultivars were able to acclimatize to Cd exposure, probably through mechanisms associated with reductions in the magnesium status. Cadmium concentrations varied according to the following descending order: roots = leaf blades > (peduncle + sepals) > stem = fruits.However, the tolerant cultivar accumulated more Cd than did the sensitive one.Although Cd reached the fruits from the first to the fourth bunches, peduncle and sepals may act as a barrier to Cd entrance in tomato pulp and peel. The Cd-induced changes in the fruit mineral profile varied according to plant cultivar, organ, tomato tissue, and bunch position. Moreover, plant yield was not affected by the Cd stress, which was able to improve fruit size and weight in the tolerant cultivar. In conclusion, new insights about the Cd-induced effects on tomato development and fruit attributes were provided by growing plants in soil, which is the media generally used to cultivate this crop, rather than hydroponics. It was shown that tomato cultivars with contrasting tolerance to Cd toxicity can reach sexual maturity and produce fruits with no yield losses, despite impacts on development from long-term Cd exposure.This study also revealed the role of floral receptacle and its related structures in limiting, even partially, Cd translocation to the fruits. Furthermore, Yoshimatsu's capacity to produce bigger and heavier fruits, in plants under Cd exposure, may probably be associated with enhanced Cd accumulation. K E Y W O R D Scadmium, environmental contamination, food security, heavy metals, Solanum lycopersicum

Co‐inoculation ofBacillussp. andPseudomonas putidaat different development stages acts as a biostimulant to promote growth, yield and nutrient uptake of tomato

“…Micronutrients assist tomatoes in making use of primary nutrients and are essential to the development of fruit and seed (Carvalho et al 2018). The co-inoculation with three microbes increased the Ca and B content in fruits.…”

Ultrastructural and metabolic disorders induced by short‐term cadmium exposure in Avicennia schaueriana plants and its excretion through leaf salt glands

“…; Carvalho et al . ,b). Due to the similarity of Cd to Zn ions, Zn may be replaced by Cd in some metalloenzymes, affecting their functions, as indicated by Shaw et al .…”

The sweet side of misbalanced nutrients in cadmium‐stressed plants

“…Roots, which generally have higher Cd concentrations than do shoots (Kato, Carvalho, Gaziola, Piotto, & Azevedo, ; Piotto et al, ), should be able to quickly activate protective mechanisms to counteract the entrance of positive charges originating from Cd accumulation. One of these mechanisms is probably associated with reducing concentrations of positively charged nutrients in roots; this mechanism can involve enhancing translocation of Mn (and also Zn) from roots to shoots (Borges et al, ; Carvalho, Piotto, Franco, ; Carvalho et al, ) (Figures and ) and may be further potentiated by either decreasing uptake (Carvalho, Piotto, Gaziola, et al, ) or increasing exclusion in the root system. A decreased Mn concentration was observed in roots of Brassica campestris accessions, which improved plant biomass after being subjected to Cd exposure (Zhu, Sun, Fang, Qian, & Yang, ).…”