Interactive effects of cadmium and Microcystis aeruginosa (cyanobacterium) on the growth, antioxidative responses and accumulation of cadmium and microcystins in rice seedlings

Abstract

Cadmium pollution and harmful cyanobacterial blooms are two prominent environmental problems. The interactive effects of cadmium(II) and harmful cyanobacteria on rice seedlings remain unknown. In order to elucidate this issue, the interactive effects of cadmium(II) and Microcystis aeruginosa FACHB905 on the growth and antioxidant responses of rice seedling were investigated in this study, as well as the accumulation of cadmium(II) and microcystins. The results showed that the growth of rice seedlings was inhibited by cadmium(II) stress but promoted by inoculation of M. aeruginosa FACHB905. cadmium(II) stress induced oxidative damage on rice seedlings. Inoculation of M. aeruginosa FACHB905 alleviated the toxicity of cadmium(II) on rice seedlings. The accumulation of cadmium(II) in rice seedlings was decreased by M. aeruginosa FACHB905, but the translocation of cadmium(II) from root to shoot was increased by this cyanobacterium. The accumulation of microcystins in rice seedlings was decreased by cadmium(II). Results presented in this study indicated that cadmium(II) and M. aeruginosa had antagonistic toxicity on rice seedlings. The findings of this study throw new light on evaluation of ecological- and public health-risks for the co-contamination of cadmium(II) and harmful cyanobacteria.

The Importance of Microorganisms for Sustainable Agriculture—A Review

“…Cucumis sativus -protection against anthracnose (Colletotrichum orbiculare) via the induction of SAR [64] Chlorella oocystoides, Chlorella minutissima Zea mays -enhanced chlorophyll, P, and K content -improved biomass [65] Chlorella vulgaris Telfairia occidentalis -enhanced germination ratio -higher number of leaves and yield -improved chlorophyll, carbohydrates, proteins, and lipid content [66] Microcystis aeruginsa Oryza sativa -heavy metal (Cd) stress alleviation with decreased Cd accumulation, increased translocation of Cd from root to shoot, and enhanced dry weight [67] Nostoc sp.…”

Effect of Cadmium, Copper and Lead on the Growth of Rice in the Coal Mining Region of Quang Ninh, Cam-Pha (Vietnam)

“…This mechanism may be suggested by the results in Figure 3a where the local cultivar (Nep cai hoa vang) grows closer to control values in the presence of 5 and 10 µmol/L Cd and may be therefore adapted to high Cd concentrations. Rice plants have been shown to develop trace metal protection mechanisms by sequestering metals in roots or by combining them with deprotonated organic acids, proteins, and polysaccharides [52]. For the 5 and 10 µmol/L Cd conditions, the results in Figure 3a show further a significant decrease in biomass for the Asia variety of 41% and 60% respectively with respect to the control at 0 µmol/L Cd.…”

“…Photosynthetic reactions involving photosystem II (PSII) have been proposed to be the principal target of Cu toxicity. In rice plants, Cu has been associated with the production of reactive oxygen species (ROS), leading to oxidative stress [52,55]. For sensitive plant species, such as local rice variety in Vietnam, 3.2 mg/kg (equivalent to 50 µmol/L Cu) were shown to be toxic, yielding decrease of about 10-20% in root biomass as shown in Figure 3b.…”

Microcystin Contamination in Irrigation Water and Health Risk

“…According to [ 66 ], the leaf weight of Spinacia oleracea decreases considerably after 21 days of MC exposure (50 and 100 µg/L). Numerous investigations have demonstrated that Oryza sativa roots, stems, and leaves exhibit increased biomass, surface area, and dry weight when exposed to low concentrations of MCs [ 67 , 68 , 69 ]. Exposure to increased concentrations of MC for 7 days had negative effects on the growth of rice plants, reflected in a decrease in the dry weight of roots, stems, and leaves, in addition to the inhibition of photosynthesis [ 70 ].…”