Partial purification and properties of apoplastic β-1,3 glucanases of groundnut leaves treated with glucan isolated from a biocontrol agent,Acremonium obclavatum

Abstract

Apoplastic β-1,3 glucanases (G1, G2) of Arachis hypogaea L. (peanut) leaves treated with glucan have been partially purified by ammonium sulphate precipitation, sephadex G-100, CM-Sephadex, DEAE-Sephadex chromatography, and preparative native PAGE electrophoretic techniques. The pI values of purified enzymes G1 and G2 were near 8 and 4, respectively. The apparent molecular masses of purified glucanases G1 and G2 from glucan-treated peanut leaves were 36 and 34 kDa, respectively. Both isoforms (G1 and G2) showed their pH optimum of 5.0 and temperature optimum of 40°C. The partially purified enzymes hydrolysed laminarin better than other substrates and inhibited uredospore germination of Puccinia arachidis. Both isoforms (G1 and G2) inhibited spore germination of some biocontrol agents such as Acremonium obclavatum W. Gams, Myrothecium verrucaria (Alb. Schw.) Ditmer, Fusarium solani (Mart.) Sacc., and Trichoderma harzianum Rifai.Key words: Acremonium obclavatum, Arachis hypogaea, β-1,3 glucanase, glucan, inhibition, Puccinia arachidis.