Plant cell biology in the new millennium: new tools and new insights.

The highly regulated structural components of the plant cell form the basis of its function. It is becoming increasingly recognized that cellular components are ordered into regulatory units ranging from the multienzyme complexes that allow metabolic channeling during primary metabolism to the "transducon" complexes of signal transduction elements that allow for the highly efficient transfer of information within the cell. Against this structural background the highly dynamic processes regulating cell function are played out. Recent technological advances in three areas have driven our understanding of the complexities of the structural and functional dynamics of the plant cell. First, microscope and digital camera technology has seen not only improvements in the resolution of the optics and sensitivity of detectors, but also the development of novel microscopy applications such as confocal and multiphoton microscopy. These technologies are allowing cell biologists to image the dynamics of living cells with unparalleled three-dimensional resolution. The second advance has been in the availability of increasingly powerful and affordable computers. The computer control/analysis required for many of the new microscopy techniques was simply unavailable until recently. Third, there have been dramatic advances in the available probes to use with these new microscopy approaches. Thus the plant cell biologist now has available a vast array of fluorescent probes that will report cell parameters as diverse as the pH of the cytosol, the oxygen level in a tissue, or the dynamics of the cytoskeleton. The combination of these new approaches has led to an increasingly detailed picture of how plant cells regulate their activities.