Variability in antifungal proteins in the grains of maize, sorghum and wheat

Abstract

Crude protein extracts were made from kernels of 12 cultivars each of maize, sorghum and wheat. These preparations were fractionated on sodium dodecyl sulfate (SDS)‐polyacrylamide gels and subjected to Western blot analyses. Bands corresponding to chitinases and β‐glucanases were identified immunologically (Western blots) and on activity gels. Ribosome Inactivating Protein(s) (RIP) and permatins were identified immunologically. In maize, two chitinase bands (25–29 kDa) were seen in all cultivars, and a third band of about 23 kDa was detected in 7 of the 12 cultivars. Two or three β‐glucanase bands of sizes between 24 and 36 kDa (probably a mixture of 1,3–β‐ and 1,3–1,4‐β‐glucanases) were detected in blots of SDS gels, and one band was detected in activity gels (1,3‐β‐glucanase). In sorghum, one chitnase band of approximately 29 kDa, and two or three additional bands ranging in size from 21–24 kDa were observed. Only one β‐glucanase band was identified, with an estimated molecular weight of 30 kDa. All bands that appeared on Western blots of SDS gels corresponded to bands detected on activity gels. In wheat, one chitmase band of around 20 kDa, one β‐glucanase band of about 30 kDa and one RIP band of about 30 kDa were identified. Permatins (molecular weight about 22 kDa) were identified in maize, sorghum and wheat, with the different cultivars having varying amounts of permatins.