Physiological and biochemical responses of Eichhornia crassipes exposed to Cr (III)

Abstract

The effect of exposure of Eichhornia crassipes to Cr (III) was assessed by measuring changes in photosynthetic pigments, malondialdehyde, superoxide dismutase, glutathione reductase, catalase, and guaiacol peroxidase activities, as well as Cr concentration in tissues. Cr concentration in roots was significantly higher than in aerial parts and increased with Cr concentration in water. Photosynthetic pigments increased significantly, whereas the activities of antioxidant enzymes varied differently in plant tissues. Low Cr concentrations induced a rapid response of E. crassipes during short-term exposure, implying that the antioxidant system conferred redox homeostasis. Results showed that Cr (III) was more toxic at the two highest concentrations and long-term exposure, while it was not harmful but beneficial at the two lowest concentrations and short-term exposure. This work concludes that E. crassipes was able to grow under Cr (III) stress by protecting itself with an increase in the activity of its antioxidant system.

Hormesis in Plants: The Role of Oxidative Stress, Auxins and Photosynthesis in Corn Treated with Cd or Pb

“…Conversely, González et al [11] observed a decrease in the chlorophyll content and PSII performance in barley plants, which simultaneously showed an increase in growth that was caused by Cd treatment. Generally, the stimulation of growth by Cd is positively correlated with a significant decrease in the total chlorophyll content and activity of the photosystems [11,43]. The results presented in this paper also confirmed this relationship, which may additionally prove the high toxic effect of Cd on these parameters (Figures 3a, 4 and 6a).…”

“…On the other hand, improvements in the content of photosynthetic and accessory pigments (such as chlorophyll a, chlorophyll b, total chlorophyll and/or carotenoids) were observed in the leaves of different plant species after Cd exposure [4]. Conversely, González et al [11] observed a decrease in the chlorophyll content and PSII performance in barley plants, which simultaneously showed an increase in growth that was caused by Cd treatment. Generally, the stimulation of growth by Cd is positively correlated with a significant decrease in the total chlorophyll content and activity of the photosystems [11,43].…”

“…Growth, oxidative stress and/or photosynthetic activity are the physiological parameters that are most frequently examined by scientists who are interested in hormesis in plants [3,4,[8][9][10][11]. Many 2 of 21 scientists have connected the stimulation of plant growth during hormesis with a low level of oxidative stress [3,7,8,10,12].…”

The Role of Heavy Metals in Plant Response to Biotic Stress

“…This effect was also caused by As in the case of Spirodela polyrrhiza L. [ 65 ]. Besides, numerous experiments with chromium (Cr) revealed hormetic growth in the cases of Eichhornia crassipes [ 67 ], Salsola kali L. [ 68 ], Lemna minuta [ 69 ], Allium cepa L. [ 70 ] and Capsicium annum L. [ 71 ]. An hormetic response was observed as well, in the case of elements such as lanthanum (La) for Lonicera japonica [ 72 ], Oryza sativa L. [ 73 ] and Arabis paniculata [ 66 ], Pb for Pisum sativum [ 35 ], Brassica pekinensis [ 74 ] and Dianthus carthusianorum [ 60 ], Hg for Anthyllis vulneraria [ 75 ] and Helianthus tuberosus [ 76 ], palladium (Pd) for P. sativum L. [ 77 ], platinum (Pt) for Arabidopsis thaliana [ 78 ], uranium (U) for Schizachyrium scoparium [ 79 ], Zn for Thlaspi caerulescens [ 80 ], Sedum alfredii [ 57 ] and Arabis paniculata [ 66 ].…”

Effect of pH on Cr(III) accumulation, biomass production, and phenolic profile in 2 Salvinia species

“…In this context, it has been assumed that Cr(III) at low concentrations can be beneficial to plants, although it is highly toxic at high concentrations (Singh et al ). However, increasing evidence indicates that Cr(III) causes more toxic than beneficial effects on both aquatic and terrestrial plants (Karuppanapandian and Kumariah ; González et al ; Lukina et al ). Even in some lower and higher plants, such as Pseudokirchneriella subcapitata , Chlorella kessleri , and Salsola kali , Cr(III) seems to be more toxic than Cr(VI) (Gardea‐Torresdey et al ; Vignati et al ).…”