Insights into molecular mechanisms of mutual effect between plants and the environment. A review

Higher plants play a major role in keeping a stable environment on the globe. They regulate global climate and surroundings in many ways at different levels such as molecular, cellular, organ, individual, community, regional, ecosystem and global ecosystem levels. This article will focus on the abiotic aspect of the environment. Readers interested in the biotic aspect can read recent publications by Garcia-Brugger et al. [Early signalling events induced by eliators of plant defenses, Mol. Plant Microbe In. 19 (2006) 711-724], Lecourieux et al. [Calcium in plant defence-signalling pathways, New Phytol. 171 (2006) 249-269], and Conrath et al. [Priming: Getting ready for battle, Mol. Plant Microbe In. 19 (2006) 1062-1071], for related progress. Plant behavior and character expression are controlled at the molecular level by gene expression and environmental cues. In a persistently changing environment there are many abiotic adverse stress conditions such as cold, drought, salinity and UV-B, which influence plant growth and crop production. Unlike animals, higher plants, which are sessile, cannot escape from their surroundings, but adapt themselves to changing environments by inducing a series of molecular responses to cope with these problems. The physiological processing basis for these molecular responses is the integration of many transduced events into a comprehensive network of signaling pathways. Here, higher plant hormones occupy a central place in this transduction network, frequently acting in conjunction with other signals, to regulate cellular processes such as division, elongation and differentiation, which are the fundamental basis for higher plant development and related character expression. Stress factors are also major ecological factors influencing the environment, which are general environmental stimuli and cues to higher plants. Molecular responses to environmental stresses have been studied intensively over the last few years. The findings show an intricate network of signaling pathways controlling perception of environmental signals, the generation of second messengers and signal transduction. In this review, up-to-date progresses are introduced in terms of functional analysis of signaling components and issues with respect to the agricultural environment and sustainable development. These advances mainly include identification of the abiotic stress-responsive genes, extensive realization of the mutual concerted relationship between plants and the environment on different scales, molecular mechanisms of stress signal transduction and pathways, and so on. Here, a general network of stress-responsive gene expression-control model is proposed, with an emphasis on the integration between stress signal transduction pathways and the agricultural environment