Lead Induced Modulation in Growth, Chlorophyll Pigment, Nutrient Uptake, Antioxidant Enzyme Regulation, Gene Expression and Fruit Quality in two Tomato Cultivars
Year: 2020
Type: article
Abstract: Metal stress is one of the major restrictions for agricultural production.A pot experiment was set-up to appraise modulation in growth, oxidative defense, secondary metabolism and relative gene expression of two tomato cultivars viz., Roma (sensitive) and Nagina (tolerant) at flowering stage in response to different lead (Pb 2+ ) regimes (160, 320, 640 and 1280 μM).The results showed that Pb 2+ stress (1280 μM Pb) caused a considerable reduction in growth attributes, chlorophyll (Chl.)pigments and ascorbic acid contents, and increase in malondialdehyde (MDA), hydrogen peroxide (H 2 O 2 ), and total soluble protein (TSP) contents in both cultivars.A significant enhancement in ascorbate peroxidase (APX), peroxidase (POD), catalase (CAT) activities and Cat2 gene expression was documented in Pb 2+ stressed tomato plants.Fruit quality of Nagina was better than Roma cultivar.In this context, higher fruit ash contents, protein contents, fructose and glucose contents were observed in Nagina while Roma was inferior in this regard when under Pb 2+ stress.Furthermore, Pb 2+ reduced the fresh and dry biomass, moisture, fiber content and mineral (Na + , K⁺ and Ca²⁺) uptake in tomato fruits of both cultivars.The results indicated that significant amount of Pb 2+ accumulates in the root compared with its concentration in shoot and leaves while only a small amount of Pb 2+ reaches the fruit.The exposure to Pb 2+ caused significant changes in Cat2 gene transcripts indicating the contribution of this gene in Pb 2+ tolerance.The sensitive cultivar exhibited higher oxidative damage, decreases in the concentration of essential nutrients, poor oxidative defense system, and thus had low quality fruit.
Authors: Zarbakht Afzaal, Iqbal Hussain, Muhammad Arslan Ashraf, Rizwan Rasheed, Muhammad Tariq Javed, Mahmood-ur-Rahman Ansari, Sumera Anwer, Muhammad Iqbal
Language: English
Subfield: Plant Science
Domain: Life Sciences
SDG: Zero hunger
Open Access status: bronze
OpenAlex ID: W4417522860