The heat‐stable protein fraction from Opuntia ficus‐indica seeds exhibits an enzyme protective effect against thermal denaturation and an antibacterial activity

Abstract

Desiccation tolerance in developing seeds occurs through several mechanisms among which, a common group of proteins named dehydrins has received considerable attention. So far, there is no information dealing with the accumulation of dehydrins in seeds of Opuntia ficus‐indica. We have initiated here an extraction protocol based on two critical steps: heat and acid treatments, and the purity of this fraction was analyzed by FTIR spectroscopy. Western blot analysis of the heat‐stable protein fraction (HSF) revealed two main bands of approximately 45 and 44 kDa, while three others of ∼40, 32, and 31 kDa were faintly visible, which were recognized by anti‐dehydrin antibodies. This fraction exhibited a Cu2+‐dependent resistance to protease treatments. Next, we performed a series of assays to compare the functional properties of the HSF with those of the previously characterized wheat dehydrin (DHN‐5). Antibacterial assays revealed that HSF exhibits only moderate antibacterial activities against gram‐negative and gram‐positive bacteria, with a minimum inhibition concentration ranging from 0.25 to 1 mg/ml. However, in vitro assays revealed that compared to DHN‐5, HSF exhibits higher protective activities of the lactate dehydrogenase (LDH) when exposed to heat, freezing, and dehydration stresses. The protective role of HSF seems to be linked to its best ability to minimize protein aggregation.

An Updated Review: Opuntia ficus indica (OFI) Chemistry and Its Diverse Applications

“…The statistics of this analysis demonstrated that seed oil has no antibacterial action for Pseudomonas aeruginosa, while Staphylococcus aureus and Escherichia coli exhibited antibacterial properties [100]. The antimicrobial assays conducted in this study focused on specific bacterial strains, including Gram-negative bacteria such as Agrobacterium tumefaciens and Escherichia coli as well as Gram-positive bacteria like Micrococcus aureus, on 96-well microplates by the broth microdilution method for 24 h at 37 • C, inhibiting growth in minimum extract concentrations [101].…”

Plant dehydrins and dehydrin-like proteins: characterization and participation in abiotic stress response

“… Szabała (2023) also showed the cryoprotective activity of purified DHN24 in the enzymatic assay and inhibition of bacterial growth under DHN24 overexpression. Interestingly, wheat DHN-5 showed weaker LDH protective effects than the heat-stable protein fraction from Opuntia ficus-indica seeds ( Drira et al., 2013 ; Drira et al., 2023 ). Some vacuolar Ca 2+ -binding proteins also showed cryoprotective activity against LDH ( Osuda et al., 2021 ).…”

Colonization of root endophytic fungus Serendipita indica improves drought tolerance of Pinus taeda seedlings by regulating metabolome and proteome

“…At3g17210 encodes heat stable protein 1 (HS1) 4 . Such proteins harbor short chains of amino acids; thus, they maybe function as auxiliary proteins to exhibit enzyme protective effects against abiotic stress (Drira et al, 2023). In addition, under negative ionization mode, the metabolites 4-coumaric acid and LPC18:0 were in significantly negative correlations to H9X056 and H9VDW5 (Supplementary Figure S5D and the file "I_D.vs.NI_D_neg_I_D.vs.NI_D_cor" in Supplementary Table S16), suggesting that the enrichment of the two proteins might downregulate their levels.…”