Two Mutants Affecting Adaptative Responses to Abiotic Stresses in Barley Seedlings

Abstract

Two novel mutants which affect the adaptative responses of barley seedlings to different abiotic stresses are described. They allow us to explore some aspects of adaptative phenomena that are little known in higher plants. One of these mutants corresponds to a nuclear gene which under certain circumstances in the wild type barley induces additional ethylene production in the seedling roots. This mechanism seems to be involved in inducing a negative hydrotropic growth of the roots, a phenomenon that we interpret as a response avoiding waterlogging. The other mutant corresponds to a plastid encoded gene which is involved in photosystem I and II stability and, probably, indirectly affects the acclimation of the seedlings to higher temperatures, a fact which seems to occur through the control of unsaturation/saturation levels of the thylakoid membrane fatty acids.

Keywords

• abiotic stress
• barley
• root behaviour
• temperature sensitivity