The ultimate goal of our research center (APSRC) is to establish the entire cascade of signal perception, transduction and adaption mechanisms in response to stresses. The in-depth and systematic understanding of plant stress responses will provide for the solid foundation which will help maximize the yield of crops growing under adverse environmental conditions. To achieve this goal, following divisional composition has been designed for APSRC`s research, as shown in the diagram.

Diagram:
Division 1: Perception and Transduction of Stress Signals
Division 2: Regulation of Stress Responsive Gene Expression
Division 3: Mechanism of Plant Stress Tolerance




Perception and Transduction of Stress Signals
Plants encounter a wide range of abiotic stresses, including drought, cold, and salt etc., and biotic stresses such as plant pathogen attacks. To adapt to these stresses, plants use diverse and sophisticated signaling stratagies for recognizing and responding to these stresses. The first step in switching on such molecular responses is to perceive the stress and then to relay the received information through complex signal transduction pathways.
Sensing of environmental stresses may occur at the point of initial stress perception itself. Plants might perceive the stresses in different ways, such as by sensors, receptors, elevated calcium concentrations, and changing membrane fluidity. Stress perception and signaling is translocated into biochemical reactions, metabolic adjustments and altered physiological state. Thus plants have evolved mechanisms by which they can increase their tolerance against these stresses. Consequently, there exists a complex signal network underlying plant adaptation to these adverse environmental conditions. Knowledge about the signal transduction pathways induced by the stresses is essential to develop plants with properties of high tolerance against abiotic and biotic stresses.
The progress in our understanding of the signaling pathways, leading from the environmental stimulus to end response in plant, has been rapid over recent years through interdisciplinary studies. Nevertheless, a complete understanding of all the elements linked with perception and recognition of environmental stresses in plants has yet to be achieved.
The main goal of the Division ¥° is to elucidate the signal perception and transduction pathways associated with abiotic and biotic stresses. A combined use of genetic, genomic, biochemical and cell biological techniques will be made to identify the sensors and receptors that perceive the environmental signals. This will lead to a greater understanding of the abiotic and biotic stress pathways and will also lead into work related to sensors and receptors in order to discover exactly how these proteins operate to perceive the environmental signals and relay information to down-stream of signal transduction pathway.


Regulation of Stress Responsive Gene Expression
Plant cells are capable of managing a variety of stresses by induction of specific genes. The stress-responsive gene expression leads to the presentation of defense proteins that play key roles in the adaptation process of plants against diverse stimuli including biotic and abiotic stresses. Research Division 2 primarily focuses on analyzing promoter sequences of the stress-responsive genes, characterizing the associated trans-acting factors, elucidating their interactions in the gene expression mechanism, and eventually utilizing characterized genes for developing stress-resistant transgenic plants. Specific aims of the Research Division 2 are characterization of transcription factors in the abscisic acid dependent stress-responsive pathway, functional analysis of the ubiquitin pathway and the octadecanoid pathway in stress responses, relationship of peroxidase gene expression in the regulation of oxidative stress, the regulation mechanism of specific gene expression in salt and drought stress, characterization of induced systemic resistance genes in Rhizobacteria. The knowledges collected on the mechanism of stress-responsive gene expression are to be combined and the fundamental clues to manage stresses will be provided. Selected genes will be manipulated and introduced into plants to produce stress resistant transgenic palnts.


Mechanism of Plant Stress Tolerance
Plants have a set of defense mechanisms that provide protection against a variety of external stimuli, including biotic and abiotic stresses. These defense mechanisms involve multicomponent response systems, such as induction of defense genes, induction of systemic acquired resistance, production of pathogenesis-related (PR) proteins, accumulation of stress metabolites and the reinforcement of cell wall and cuticle. These autonomous defense mechanisms are activated when extracellular signals are recognized by plant receptors and transmitted via intracellular signal transduction cascades to defense-related genes. In research division ¥², we are investigating the cellular and biochemical responses of plant cells to overcome the adverse effects triggered by various stresses. In particular, our division focuses on the relation between the terpenoid biosynthesis and the environmental stresses by measuring the primary and the secondary isoprenoid metabolites. We are also studying the mechanisms of photosynthesis inhibition and accumulation of photosensitizing compounds by inhibiting the porphyrin synthesis pathway. In addition to the biosynthetic pathway studies, we will generate transgenic plants which are resistant to several stresses, including low temperature and pathogens, by introducing genes which can enable plants to adapt to environmental stresses or to grow better.