Differential physiological responses and tolerance to potentially toxic elements in biodiesel tree Jatropha curcas

Abstract

Environmental pollution by potentially toxic elements (PTEs) has become a serious problem with increasing industrialization and the disturbance of natural biogeochemical cycles. Jatropha is an oilseed-bearing shrub with high potential for biodiesel production in arid regions. In this study, we examined the physiological responses of this plant to five representative PTEs (Cd, Cr, Cu, Ni, and Zn) in a hydroponic culture. Application of higher concentrations of Cd and Zn led to severe leaf chlorosis, and Cd, Cu, and Ni treatments resulted in significant growth retardation. Higher enrichment of the applied PTEs in the shoots was observed for Zn- and Cd-treated plants, with the latter reaching 24-fold enrichment in plants exposed to 10 μM Cd, suggesting that Jatropha can cope with relatively higher internal concentrations of toxic Cd. Although Cd stress led to the disturbance of essential mineral homeostasis and photosynthesis, this induced an increase in thiol compounds in the roots, suggesting defensive responses of Jatropha to PTEs. This study showed that Jatropha exhibits distinct sensitivities and physiological responses to different PTEs. This study also provides basic knowledge for diagnosing the physiological status of Jatropha trees for potential dual use in afforestation and as a sustainable energy supply.

Phytoremediation of Cadmium: Physiological, Biochemical, and Molecular Mechanisms

“…In some studies, Cd toxicity is linked with the low dry matter accumulation in roots [4], turning them black [38], and leads to a reduction in lateral root growth [39]. It has further been associated with root development with the mature apoplastic pathway, enhanced porosity, and few root tips per surface area in rice plants [40].…”

Influence of Monosporascus root rot and vine decline disease on the amino acid metabolism of watermelon fruit

“…Mineral contents of the watermelon flesh sample were determined as described previously (Yamada et al, 2018) with the following modifications. The homogenized watermelon flesh sample (0.5 g) was placed into a 50 ml Erlenmeyer flask, to which 10 ml of nitric acid (Electric industry grade, 70%, density 1.42 g ml -1 , Fujifilm Wako Pure Chemical, Osaka, Japan) was added.…”

Use of Carbonized Fallen Leaves of Jatropha Curcas L. as a Soil Conditioner for Acidic and Undernourished Soil

“…The unamended soil was decomposed by concentrated sulfuric acid as described previously [46] and their mineral contents were measured by inductively coupled plasma atomic emission spectroscopy (ICP-AES) (SPECTRO CIROS CCD; SPECTRO Analytical Instruments GmbH, Nordrhein-Westfalen, Germany). The biochar and aerial parts of the harvested plants were decomposed as described previously [47] with the following modifications. Dry samples of the biochar (0.2 g) and aerial parts (0.1 g) were dissolved in 10 mL of concentrated nitric acid in a flask and digested on a hot plate for 1 h at each of 90 • C, 140 • C, and 190 • C. The solutions were then evaporated at 220 • C (biochar) or 240 • C (aerial parts) until the volume was reduced to approximately 1 mL and analyzed by ICP-AES as described above.…”