Wirkung wachstumsretardierender Verbindungen auf Gibberellin-Gehalte und -Transport sowie auf das Sproßwachstum von Triticum und Secale

Abstract

Summary The effect of (2-chloroethyl)-trimethylammoniumchloride (CCC), N,N-dimethyl-N-(2-bromoethyl)-hydraziniumbromide (BMH), Na-(2,3-dichloro)-isobutyrate (DCiB), 2-methyl-1,2-di-[(3′)- pyridyl]-propane-1-one (MP), and 2-chloroethylphosphonic acid (CEPA) was investigated on shoot axis growth, contents of GA 1 and GA 3 and on [U- 3 H]-GA 3 transport. All reagents reduced shoot axis growth as well as the GA 3 contents per g dry matter and per plant. The reduction in GA 1 contents was low. The determination coefficients calculated for Triticum aestivum were r 2 GA 1 = 0,6782 and r 2 GA 3 = 0,8468, and for Secale cereale r 2 GA 1 = 0,7583 and r 2 GA 3 = 0,8095. The effect of CCC, BMH and MP on shoot axis growth could be prevented by simultaneous application of GA 3 but not by kinetin or IAA. The growth inhibition caused by DCiB, however, could not be compensated completely by any phytohormone application. DCiB inhibited the transport of [U- 3 H]-GA 3 from the ear to the sites of action in the stalks. The transport inhibition of GA 3 may cause the failure to compensate completely DCiB effects on growth by GA 3 application. The results suggest that all plant growth retarding compounds studied control shoot axis growth by influencing the gibberellin metabolism.