Low-Temperature-Induced GA₃ Sensitivity of Wheat. III. Comparison of Low Temperature Effects on α-Amylase Production by Aleurone Tissue of Dwarf and Tall Wheat

Abstract

The low temperature effect on the gibberellic acid (GA₃) sensitivity (measured as a-amylase production) of aleurone tissue or deembryonated seed of dwarf and tall wheat (F₆ Rht 3/rht 3 isogenic lines) was studied. The results indicated that the low-temperature-induced increase in GA₃ response is: quantitative and temporal; GA₃ concentration-dependent; without effect on the lag-time of a-amylase production, and operative in the aleurone tissue of dwarf (Rht 3-containing) wheat. All these characteristics of the low temperature response of the Rht 3-containing aleurone tissue are similar to those reported earlier for Rht 1-containing and Rht 2-containing aleurone tissue. The present results support the hypothesis that low temperature exposure is able to cure or reverse the genetic lesions manifest in the aleurone tissue containing the Rht allele and that this may be mediated via an increase in GA₃ receptor sites.