Effect of earthworms on growth, photosynthetic efficiency and metal uptake in Brassica juncea L. plants grown in cadmium-polluted soils

• Published in: Environmental science and pollution research international Vol. 24; no. 15; pp. 13452 - 13465
• Main Authors: Kaur, Parminder, Bali, Shagun, Sharma, Anket, Vig, Adarsh Pal, Bhardwaj, Renu
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.05.2017; Springer Nature B.V
• Subjects: Ammonia; Animals; Aquatic Pollution; Atmospheric Protection/Air Quality Control/Air Pollution; Brassica; Brassica juncea; Cadmium; Cadmium - metabolism; Carbon dioxide; carotenoids; Chalcone synthase; Chlorophyll; Chlorophyllase; Conductance; Earth and Environmental Science; earthworms; Ecotoxicology; Efficiency; Environment; Environmental Chemistry; Environmental Health; Environmental science; Enzymes; Gas exchange; Gene expression; Inoculation; Metal concentrations; Moisture content; Mustard Plant - metabolism; naringenin-chalcone synthase; Oligochaeta; Oligochaeta - metabolism; Osmoprotectants; osmotolerance; Phenylalanine; phenylalanine ammonia-lyase; Photosynthesis; Photosynthesis - drug effects; Photosynthetic pigments; Phytoene synthase; Phytoremediation; Pigments; Plant growth; Plant Roots - metabolism; Research Article; Resistance; roots; Shoots; Soil; Soil pollution; Stomata; Stomatal conductance; Supplements; toxicity; Transpiration; Waste Water Technology; Water content; Water Management; Water Pollution Control; Worms; Osmoprotectants; Chlorophyllase; Gene expression; Tolerance index; Stomatal conductance; Phytoremediation
• ISSN: 0944-1344; 1614-7499; 1614-7499
• DOI: 10.1007/s11356-017-8947-z

The present study has been carried out to examine the role of earthworms in phytoremediation of Cd and its effect on growth, pigment content, expression of genes coding key enzymes of pigments, photosynthetic efficiency and osmoprotectants in Brassica juncea L. plants grown under cadmium (Cd) metal stress. The effect of different Cd concentrations (0.50, 0.75, 1.0, 1.25 mM) was studied in 30 and 60-day-old plants grown in soils containing earthworms. It was observed that earthworm inoculation showed stimulatory effect on phytoremediation capacity and Cd uptake has increased by 49% (in 30-day-old plants) and 35% (in 60-day-old plants) in shoots and 13.3% (in 30-day-old plants) and 10% (in 60-day-old plants) in roots in 30 and 60-day-old plants in Cd (1.25 mM) treatments. Plant growth parameters such as root and shoot length, relative water content and tolerance index were found to increase in the presence of earthworms. Recovery in photosynthetic pigments (chlorophyll and carotenoid) and gas exchange parameters, i.e. net photosynthetic rate ( P n ), stomatal conductance ( G s ), intercellular CO 2 concentration ( C i ) and transpiration rate ( E t ), was observed after earthworm’s supplementation. Modulation in expression of key enzymes for pigment synthesis, i.e. chlorophyllase, phytoene synthase, chalcone synthase and phenylalanine ammonia lyase, was also observed. The results of our study revealed that earthworms help to mitigate the toxic effects produced by Cd on plant growth and photosynthetic efficiency along with enhanced phytoremediation capacity when co-inoculated with Cd in soil.