Comparison of the endogenous gibberellins in the shoots and roots of vernalized and non-vernalized chinese spring wheat seedlings

Abstract

Endogenous gibberellins (GAs) in Chinese Spring wheat seedlings were isolated by high performance liquid chromatography (HPLC) and identified by combined capillary gas chromatography-selected ion monitoring (GC-SIM). Gibberellins A 1, A 3, A 19, A 20, A 44, and A 53 were identified in the shoots, A 19 and A 20 in the roots. The identification of these 13-hydroxylated GAs demonstrates the presence of the early-13-hydroxylation pathway in wheat seedlings. Based on peak area of total ion response of five characteristic ions by GC-SIM, the approximate levels of GAs in the shoots is GA 44 > GA 19 > GA 1 = GA 3 > GA 20 for the non-vernalized wheat seedlings, and GA 44 > GA 19 > GA 53 = GA 3 > GA 1 = GA 20 for the vernalized wheat seedlings. The C 20 GAs, GA 53, GA 44 and GA 19, are present in shoots of the vernalized (flowering) wheat seedlings at somewhat higher levels than that in the non-vernalized (rapidly growing) wheat seedlings. Approximate levels of the C 19 GAs, GA 20, GA 1 and GA 3 were lower in the shoots of the vernalized wheat seedlings than in the non-vernalized wheat seedlings. The conversion of GA 19 to GA 20 (C 20 to C 19 GAs) may be a rate-limiting step in the vernalized wheat seedlings.