서필준 교수

Drought stress activates several defense responses in plants, such as stomatal closure, maintenance of root water uptake, and synthesis of osmoprotectants. Accumulating evidence suggests that deposition of cuticular waxes is also associated with plant responses to cellular dehydration. Yet, how cuticular wax biosynthesis is regulated in response to drought is unknown. We have recently reported that an Arabidopsis thaliana abscisic acid (ABA)-responsive R2R3-type MYB transcription factor, MYB96,

Plant adaptive responses to drought are coordinated by adjusting growth and developmental processes as well as molecular and cellular activities. The root system is the primary site that perceives drought stress signals, and its development is profoundly affected by soil water content. Various growth hormones, particularly abscisic acid (ABA) and auxin, play a critical role in root growth under drought through complex signaling networks. Here, we report that a R2R3-type MYB transcription factor,

Cold signals interact with other environmental cues to modulate plant developmental processes. Recent studies have shown that many Pathogenesis-Related (PR) genes are induced and disease resistance is enhanced after exposure to low temperatures, linking cold signals with pathogenesis in plants. However, the underlying molecular mechanisms and signaling schemes are largely unknown. Here, we demonstrate that cold stimulates proteolytic activation of a plasma membrane-tethered NAC (NAM/ATAF1/2/CUC2

*The Arabidopsis MYB96 transcription factor plays a role in abscisic acid (ABA)-mediated drought response. Notably, anthocyanins accumulate in the activation-tagging myb96-1d line, suggesting a role of MYB96 in biotic and abiotic stress responses in plants. Here, we investigate the role of MYB96 in salicylic acid (SA) biosynthesis and plant defense and explore the mechanisms underlying the ABA-SA interaction. *myb96-1d and myb96-1 were subject to pathogen infection assays, and expression of SA b

The circadian clock synchronizes biological processes to daily cycles of light and temperature. Clock components, including CIRCADIAN CLOCK-ASSOCIATED1 (CCA1), are also associated with cold acclimation. However, it is unknown how CCA1 activity is modulated in coordinating circadian rhythms and cold acclimation. Here, we report that self-regulation of Arabidopsis thaliana CCA1 activity by a splice variant, CCA1β, links the clock to cold acclimation. CCA1β interferes with the formation of CCA1α-CC

There has been a long-standing interest in the role played by sugars in flowering. Of particular interest is how sugar-related signals are integrated into flowering genetic pathways. Here, we demonstrate that the INDETERMINATE DOMAIN transcription factor AtIDD8 regulates photoperiodic flowering by modulating sugar transport and metabolism. We found that whereas AtIDD8-deficient idd8 mutants exhibit delayed flowering under long days, AtIDD8-overexpressing plants (35S:IDD8) show early flowering. I

Various environmental stresses limit plant growth, development, and reproductive success. Plants have therefore evolved sophisticated adaptive responses to deal with environmental challenges. The responses of plants to environmental stresses are mainly mediated by abscisic acid (ABA)-dependent and ABA-independent signaling pathways. While these two pathways have been implicated to play discrete roles in abiotic stress responses, accumulating evidence suggests that they are also intertwined. Here

Plants exhibit remarkable regeneration capacity, ensuring developmental plasticity. In vitro tissue culture techniques are based on plant regeneration ability and facilitate production of new organs and even the whole plant from explants. Plant somatic cells can be reprogrammed to form a pluripotent cell mass called the callus. A portion of pluripotent callus cells gives rise to a fertile shoot via de novo shoot organogenesis (DNSO). Here, we reconstitute the shoot regeneration process with four

Cellular dedifferentiation, the transition of differentiated somatic cells to pluripotent stem cells, ensures developmental plasticity and contributes to wound healing in plants. Wounding induces cells to form a mass of unorganized pluripotent cells called callus at the wound site. Explanted cells can also form callus tissues in vitro. Reversible cellular differentiation-dedifferentiation processes in higher eukaryotes are controlled mainly by chromatin modifications. We demonstrate that ARABIDO

Transcription factors play a central role in the gene regulatory networks that mediate various aspects of plant developmental processes and responses to environmental changes. Therefore, their activities are elaborately regulated at multiple steps. In particular, accumulating evidence illustrates that post-transcriptional control of mRNA metabolism is a key molecular scheme that modulates the transcription factor activities in plant responses to temperature fluctuations. Transcription factors ha