Polyamines Contribution to the Improvement of Crop Plants Tolerance to Abiotic Stress

Abstract

Plant development and productivity are negatively regulated by environmental stresses. The loss of productivity is triggered by a series of morphological, physiological, biochemical and molecular stress-induced changes. The development of diverse strategies to obtain stress-tolerant plants are currently one of the most active fields in plant research, which is expected to help preventing the dramatic reduction in crop yields due to global changing effects. Therefore, the identification of stress-regulatory genes and signaling molecules involved in the process of stress tolerance should allow the development of novel strategies to obtain tolerant plants. Polyamines (PAs) are polycationic compounds with a recognized role in plant growth and development, as well as in abiotic and biotic stress responses. In this chapter, we review and discuss the information concerning the modifications in polyamines levels in response to drought, salinity and cold stresses, focusing on crop species. The comparison of common and specific responses in different crop plants suggests the view that polyamines actively participate in stress signaling through an intricate metabolic network. However, the precise mechanism(s) of action by which PAs could protect crop plants from challenging environmental conditions remains unclear.