Proteomic analysis of T. qataranse exposed to lead (Pb) stress reveal new proteins with potential roles in Pb tolerance and detoxification mechanism

Kamal Usman; Serhiy Souchelnytskyi; Mohammad A Al-Ghouti; Nabil Zouari; Mohammed H Abu-Dieyeh

doi:10.3389/fpls.2022.1009756

Proteomic analysis of T. qataranse exposed to lead (Pb) stress reveal new proteins with potential roles in Pb tolerance and detoxification mechanism

Front Plant Sci. 2022 Oct 20:13:1009756. doi: 10.3389/fpls.2022.1009756. eCollection 2022.

Authors

Kamal Usman¹, Serhiy Souchelnytskyi², Mohammad A Al-Ghouti³, Nabil Zouari³, Mohammed H Abu-Dieyeh⁴

Affiliations

¹ Agricultural Research Station (ARS), Office of VP for Research & Graduate Studies, Doha, Qatar.
² College of Medicine, Qatar University, Doha, Qatar.
³ Environmental Science Program, Department of Biological and Environmental Sciences, College of Arts and Science, Qatar University, Doha, Qatar.
⁴ Biological Science Program, Department of Biological and Environmental Sciences, College of Arts and Science, Qatar University, Doha, Qatar.

Abstract

Soil lead (Pb) contamination is one of the environmental problems facing the modern world. Sources of Pb in soil include industrial activities such as mining and smelting processes, agricultural activities such as application of insecticide and municipal sewage sludges, and urban activities such as use of lead in gasoline, paints, and other materials. Phytoremediation is the direct use of living green plants and is an effective, cheap, non-invasive, and environmentally friendly technique used to transfer or stabilize all the toxic metals and environmental pollutants in polluted soil or groundwater. Current work in this area is invested in elucidating mechanisms that underpin toxic-metal tolerance and detoxification mechanisms. The present study aims to gain insight into the mechanisms of Pb tolerance in T. qataranse by comparative proteomics. MALDI-TOF/MS and in silico proteome analysis showed differential protein expression between treated (50 mg kg^⎯1 Pb) and untreated (0 mg kg^⎯1 Pb) T. qataranse. A total of eighty-six (86) differentially expressed proteins, most of which function in ion and protein binding, antioxidant activity, transport, and abiotic response stress, were identified. In addition, essential stress-regulating metabolic pathways, including glutathione metabolism, cellular response to stress, and regulation of HSF1-mediated heat shock response, were also enriched. Also, at 52- and 49-kDa MW band areas, up to six hypothetical proteins with unknown functions were identified. Of these, protein AXX17_AT2G26660 is highly rich in glycine amino acid residues (up to 76%), suggesting that it is a probable glycine-rich protein (GRP) member. Although GRPs are known to be involved in plant defense against abiotic stress, including salinity and drought, there is no report on their role on Pb tolerance and or detoxification in plants. Further enrichment analysis in the current study reveals that the hypothetical proteins do not interact with known proteins and are not part of any enriched pathway. However, additional research is needed to functionally validate the role of the identified proteins in Pb detoxification mechanism.

Keywords: Tetraena qataranse; glycine rich proteins; heavy metals; lead; proteomics.