Wheat cysteine proteases triticain alpha, beta and gamma exhibit mutually distinct responses to gibberellin in germinating seeds.

We cloned three novel papain-type cysteine proteases (CPs), triticain alpha, beta and gamma, from 1-d-germinating wheat seeds. Triticain alpha, beta and gamma were constituted with 461, 472 and 365 amino acid residues, respectively, and had Cys-His-Asn catalytic triads as well as signal and propeptide sequences. Triticain gamma contained a putative vacuole-sorting sequence.

Gliadain, a gibberellin-inducible cysteine proteinase occurring in germinating seeds of wheat, Triticum aestivum L., specifically digests gliadin and is regulated by intrinsic cystatins.

We cloned a new cysteine proteinase of wheat seed origin, which hydrolyzed the storage protein gliadin almost specifically, and was named gliadain. Gliadain mRNA was expressed 1 day after the start of seed imbibition, and showed a gradual increase thereafter. Gliadain expression was suppressed when uniconazol, a gibberellin synthesis inhibitor, was added to germinating seeds.

Differential expression of wheat aspartic proteinases, WAP1 and WAP2, in germinating and maturing seeds.

Two aspartic proteinase (AP) cDNA clones, WAP1 and WAP2, were obtained from wheat seeds. Proteins encoded by these clones shared 61% amino acid sequence identity. RNA blotting analysis showed that WAP1 and WAP2 were expressed in both germinating and maturing seeds.