Assessing of growth, antioxidant enzymes, and phytohormone regulation in Cucurbita pepo under cadmium stress

Abstract

One of the major problems worldwide is soil pollution by trace metal elements, which limits plant productivity and threatens human health. In this work, we have studied the effect of different concentrations of cadmium on Cucurbita pepo plants, evaluating different physiological and biochemical parameters: hormone signaling, metabolite concentration (malondialdehyde and hydrogen peroxide) and, in addition, the antioxidant enzyme activities of catalase and superoxide dismutase were evaluated. The production of biomass decreased under the Cd‐stress. The results showed that C. pepo accumulates higher amounts of Cd2+ in roots than in shoots and fruits. Cd2+ differently affected the content of endogenous phytohormones. Furthermore, data suggest an essential involvement of roots in the regulation of tolerance to trace elements. As a result, indole acetic acid content increased in roots of treated plants, indicating that this phytohormone can stimulate root promotion and growth under Cd‐stress. Similarly, salicylic acid content in roots and shoots increased in response to Cd2+, as well as abscisic acid levels in roots and fruits. In roots, the rambling accumulation pattern observed for jasmonic acid and salicylic acid suggests the lack of a specific regulation role against trace element toxicity. The activity of catalase and superoxide dismutase decreased, disrupted by the metal stress. However, the proline, malondialdehyde and hydrogen peroxide content significantly increased in Cd2+in all the analyzed tissues of the stressed plants. All these data suggest that C. pepo plants are equipped with an effective antioxidant mechanism against oxidative stress induced by cadmium up to a concentration of 500 μM.

Behavior of Cucumis sativus L. in presence of aluminum stress: Germination, plant growth, and antioxidant enzymes

“…In plants, metallic ions may have a different distribution rate, so some TME are immobilized and accumulated in root tissues such as Cd (Labidi et al., 2021), Fe (Roshani et al., 2014), As (Raab et al., 2007) and Al (Fan et al., 2020). Other cations, like Ba, are more freely transported to the aerial parts (Sleimi et al., 2021).…”

Assessment of Extraction Methods of Trace Metallic Elements in Plants: Approval of a Common Method

“…The extraction was achieved via a heated attack using six different acid digestion methods: nitric-sulfuric-perchloric acid digestion (method C) in a proportion of 10:1:0.5, v/v/v [8,9]; hydrochloric-nitric acid digestion, known as aqua regia mixture (method D), in a proportion of 3:1, v/v [10]; nitric-perchloric acid digestion (method E) in a proportion of 3:1, v/v [11]; nitric-sulfuric acid digestion (method F) in a proportion of 2:1, v/v [12]; nitrichydrochloric-perchloric acid digestion (method G) in a proportion of 5:1:0.5, v/v/v [13], and nitric-hydrochloric-sulfuric acid digestion (method H) in a proportion of 5:1:1, v/v/v [14].…”

“…However, studies by Idera et al [7] have reported that the use of mixtures of acids is generally fast and more efficient, and the most commonly used are nitric (HNO 3 ), sulfuric (H 2 SO 4 ), perchloric (HClO 4 ) and hydrochloric (HCl) acids, as well as hydrogen peroxide. For the extraction of metals from plant tissues, a variety of acid mixtures have been used, such as a nitric-sulfuric-perchloric acid mixture (10:1:0.5, v/v/v) [8,9]; hydrochloric-nitric acids known as aqua regia mixture (3:1, v/v) [10]; nitric-perchloric acid mixture (3:1, v/v) [11]; nitric-sulfuric acid mixture (2:1, v/v) [12]; nitric-hydrochloric-perchloric acid mixtures (5:1:0.5, v/v/v) [13] and nitric-hydrochloric-sulfuric acid mixtures (5:1:1, v/v/v) [14]. The choice of an individual acid or a combination of acids depends on the nature of the matrix to be decomposed [14].…”

Assessment of Tolerance to Lanthanum and Cerium in Helianthus Annuus Plant: Effect on Growth, Mineral Nutrition, and Secondary Metabolism

“…At the end of the experiments, treated plants were collected and split into two parts: shoots and roots. The shoots were rinsed with distilled water, while the roots were rinsed with CaCl 2 5% [ 26 , 27 , 28 ] to remove trace elements adsorbed on the root surface and washed twice with distilled water.…”