Urease from Cotton (Gossypium hirsutum) Seeds: Isolation, Physicochemical Characterization, and Antifungal Properties of the Protein

Abstract

Ureases (EC 3.5.1.5) are metalloenzymes that hydrolyze urea to produce ammonia and carbon dioxide These enzymes, which are found in fungi, bacteria, and plants, show very similar structures. Despite an abundance of urease in vegetal tissues, the physiological role of this enzyme in plants is still poorly understood. It has been previously described that ureases from the legumes jackbean ( Canavalia ensiformis) and soybean ( Glycine max) have insecticidal activity and antifungal properties. This work presents the physicochemical purification and characterization of a urease from cotton ( Gossypium hirsutum) seeds, the first description of this enzyme in Malvaceae. The urease content varied among different cotton cultivars. Cotton seed urease (98.3 kDa) displayed low ureolytic activity but exhibited potent antifungal properties at sub-micromolar concentrations against different phytopathogenic fungi. As described for other ureases, the antifungal effect of cotton urease persisted after treatment with an irreversible inhibitor of its enzyme activity. The data suggest an important role of these proteins in plant defense.

Ubiquitous urease affects soybean susceptibility to fungi

“…In addition, urease is involved in ammonia release (Dixon et al 1975; Krajewska 2009) and is toxic to pathogenic and pest organisms (Carlini and Polacco 2008; Carlini et al 1997; Becker-Ritt et al 2007; Menegassi et al 2008). The high number of transgenic lines with gene co-suppression obtained in this study demonstrates that overexpression of the complete GmEu 4 ORF is challenging.…”

“…It has been previously demonstrated that purified ureases from soybean (embryo-specific urease), jackbean and cotton seeds display antifungal properties (Becker-Ritt et al 2007; Menegassi et al 2008). The results of the present study consistently demonstrated that the absence of the GmEu 4 product enhanced susceptibility of the soybean plant to necrotrophic pathogens, P. herguei , Phomopsis sp.…”

“…Recent reports confirmed that jackbean ( Canavalia ensiformis ) ureases and the soybean embryo-specific urease display entomotoxic effects (Carlini and Polacco 2008; Carlini et al 1997) and that purified ureases from jackbean, soybean and cotton seeds inhibit in vitro fungal growth (Becker-Ritt et al 2007; Menegassi et al 2008). The toxic activity of the ureases against insects and fungi persisted after urease treatment with irreversible inhibitors of ureolytic activity, demonstrating that other protein domain(s), not the ureolytic active site, are involved in host defence mechanisms (Becker-Ritt et al 2007; Follmer et al 2004a, b).…”

Purification, characterization and immobilization of urease from Momordica charantia seeds

“…In silkworm, mulberry leaf urease activity could be directly related to silk production. Normally these insects feed on mulberry leaf, so the urease produced from leaf act on urea in stomach and release ammonia which is reabsorbed Itching, Psoriasis and Fungal diseases [17,18]. The plant is commonly known as "Karela" or bitter guard.…”

Plant Ureases and Related Peptides: Understanding Their Entomotoxic Properties

“…In the last fifteen years, lines of evidence of an overlooked toxicity of plant ureases toward some insects and fungi—a toxicity independent of enzyme activity—have accumulated [17,18,19,20]. Ureases are members of the arsenal of plant defense proteins, alongside lectins, ribosome inactivating proteins, proteinase inhibitors, amylase inhibitors and arcelins [16,17].…”