Molecular and Biochemical Insights Into Early Responses of Hemp to Cd and Zn Exposure and the Potential Effect of Si on Stress Response

Abstract

With the intensification of human activities, plants are more frequently exposed to heavy metals (HM). Zinc (Zn) and cadmium (Cd) are frequently and simultaneously found in contaminated soils, including agronomic soils contaminated by the atmospheric fallout near smelters. The fiber crop Cannabis sativa L. is a suitable alternative to food crops for crop cultivation on these soils. In this study, Cd (20 μM) and Zn (100 μM) were shown to induce comparable growth inhibition in C. sativa. To devise agricultural strategies aimed at improving crop yield, the effect of silicon (Si; 2 mM) on the stress tolerance of plants was considered. Targeted gene expression and proteomic analysis were performed on leaves and roots after 1 week of treatment. Both Cd- and Zn-stimulated genes involved in proline biosynthesis [pyrroline-5-carboxylate reductase (P5CR)] and phenylpropanoid pathway [phenylalanine ammonia-lyase (PAL)] but Cd also specifically increased the expression of PCS1-1 involved in phytochelatin (PC) synthesis. Si exposure influences the expression of numerous genes in a contrasting way in Cd- and Zn-exposed plants. At the leaf level, the accumulation of 122 proteins was affected by Cd, whereas 47 proteins were affected by Zn: only 16 proteins were affected by both Cd and Zn. The number of proteins affected due to Si exposure (27) alone was by far lower, and 12 were not modified by heavy metal treatment while no common protein seemed to be modified by both CdSi and ZnSi treatment. It is concluded that Cd and Zn had a clear different impact on plant metabolism and that Si confers a specific physiological status to stressed plants, with quite distinct impacts on hemp proteome depending on the considered heavy metal.

Impact of Pseudomonas sp. SVB-B33 on Stress- and Cell Wall-Related Genes in Roots and Leaves of Hemp under Salinity

“…A strengthening action of Pseudomonas sp. SVB-B33 on secondary cell wall of hemp roots is to be expected since previous studies reported the ability of C. sativa to take up silicon (Si, as silicic acid), deposit it as silica in the cell wall [12,50] and respond better to abiotic stresses in the presence of the metalloid [51,52].…”

State of the Art Review of Attributes and Mechanical Properties of Hempcrete

“…Certain metals have the ability to function as catalysts, hence, potentially expediting the carbonation process of lime. Conversely, these metals could also act as inhibitors [25][26][27].…”

Towards identifying industrial crop types and associated agronomies to improve biomass production from marginal lands in Europe

“…This land has to be remediated before re‐using for food production to protect human health and the environment. Previous works have demonstrated that several non‐food industrial crops have the ability to accumulate HM&M in their aerial biomass contributing to the removal of the toxic elements from the soil (Barbosa et al, 2016; Fernando et al, 2016; Galić et al, 2019; Guo et al, 2019; Luyckx et al, 2021; Nsanganwimana et al, 2014; Witters et al, 2009).…”