Changes in rubisco, cysteine-rich proteins and antioxidant system of spinach (Spinacia oleracea L.) due to sulphur deficiency, cadmium stress and their combination

Abstract

Sulphur (S) deficiency, cadmium (Cd) toxicity and their combinations are of wide occurrence throughout agricultural lands. We assessed the impact of short-term (2 days) and long-term (4 days) applications of cadmium (40 μg/g soil) on spinach plants grown on sulphur-sufficient (300 μM SO) and sulphur-deficient (30 μM SO) soils. Compared with the control (+S and -Cd), oxidative stress was increased by S deficiency (-S and -Cd), cadmium (+S and +Cd) and their combination stress (-S and +Cd) in the order of (S deficiency) < (Cd stress) < (S deficiency and +Cd stress). SDS-PAGE profile of leaf proteins showed a high vulnerability of rubisco large subunit (RbcL) to S deficiency. Rubisco small subunit (RbcS) was particularly sensitive to Cd as well as dual stress (+Cd and -S) but increased with Cd in the presence of S. Cysteine content in low molecular weight proteins/peptide was also affected, showing a significant increase under cadmium treatment. Components of ascorbate-glutathione antioxidant system altered their levels, showing the maximum decline in ascorbate (ASA), dehydroascorbate (DHA), total ascorbate (ASA + DHA, hereafter TA), glutathione (GSH) and total glutathione (GSH + GSSG, hereafter TG) under S deficiency. However, total ascorbate and total glutathione increased, besides a marginal increase in their reduced and oxidized forms, when Cd was applied in the presence of sufficient S. Sulphur supply also helped in increasing the activity of superoxide dismutase (SOD), ascorbate peroxidase (APX), glutathione reductase (GR) and catalase (CAT) under Cd stress. However, their activity suffered by S deficiency and by Cd stress during S deficiency. Each stress declined the contents of soluble protein and photosynthetic pigments; the highest decline in contents of protein and pigments occurred under S deficiency and dual stress respectively. The fresh and dry weights, although affected adversely by every stress, declined most under dual stress. It may be concluded that an optimal level of S is required during Cd stress for better response of SOD, APX, GR and CAT activity, as well as synthesis of cysteine. RbcS is as highly sensitive to S deficiency as RbcL is to Cd stress.

Drought and salinity induced changes in ecophysiology and proteomic profile of Parthenium hysterophorus

“…The second important feature adaptive to abiotic stress is comparatively higher accumulation of proline under negative water potentials and ionic imbalance. Proline is considered to act as an osmolyte, a reactive oxygen species (ROS) scavenger, and a molecular chaperone stabilizing the structure of proteins, thereby protecting cells from damage caused by stress [ 34 – 35 ]. The higher proline levels suggested that compatible solutes contribute to osmoregulation and detoxification of ROS [ 36 ].…”

“…Drought and salinity primarily influence the growth and development of plant. The tolerance ability of plant depends on its genetic potential that varies to species [ 34 ]. During adverse growth conditions cell cycle and cell division play a key role for maintaining cell communication and cell integrity [ 80 ].…”

Transcriptomic analysis at organ and time scale reveals gene regulatory networks controlling the sulfate starvation response of Solanum lycopersicum

“…Meta-analysis of transcriptomics data has shown that sulfate deficiencyresponsive genes are enriched in biological processes related to sulfate transport and metabolism, but also in processes related to cell wall organization, regulation of proteolysis, and metabolism of carbon and nitrogen [43]. The sulfate deficiency response has also been explored by metabolomics and proteomics analyses in Arabidopsis and crops [10,17,32,35,[44][45][46][47][48][49][50][51][52]. Furthermore, systems biology approaches that integrate multi-omics data have been adopted to generate a holistic vision of the sulfatedeficiency response [31].…”

Parthenium hysterophorus steps up Ca-regulatory pathway in defence against highlight intensities

“…Both chlorophyll a as well as chlorophyll b are vulnerable to drought and HL 23 . A decrease in chlorophyll a and chlorophyll b has been observed in some studies published earlier using various plants 11,24,25 . The ML and HL-induced changes in the leaf chlorophyll content might be attributed to disrupted biosynthesis or enhanced degradation of pigments.…”