The role of P-type IIA and P-type IIB Ca2+-ATPases in plant development and growth.

As sessile organisms, plants have evolved mechanisms to adapt to variable and rapidly fluctuating environmental conditions. Calcium (Ca2+) in plant cells is a versatile intracellular second messenger that is essential for stimulating short- and long-term responses to environmental stresses through changes in its concentration in the cytosol ([Ca2+]cyt). Increases in [Ca2+]cyt direct the strength and length of these stimuli.

Calcium dynamics in tomato pollen tubes using the Yellow Cameleon 3.6 sensor.

In vitro tomato pollen tubes show a cytoplasmic calcium gradient that oscillates with the same period as growth. Pollen tube growth requires coordination between the tip-focused cytoplasmic calcium concentration ([Ca]) gradient and the actin cytoskeleton. This [Ca] gradient is necessary for exocytosis of small vesicles, which contributes to the delivery of new membrane and cell wall at the pollen tube tip.

Co-immunoprecipitation of Plant Receptor Kinases.

In order to comprehend the function of a particular protein, identification of the interacting protein partners is a useful approach. Co-immunoprecipitation (Co-IP) is employed to test physical interactions between proteins. Specific antibodies or antibodies against tagged versions can be used to immunoprecipitate the proteins.

Expression of Plant Receptor Kinases in Yeast.

The budding yeast Saccharomyces cerevisiae is a useful system to express recombinant proteins and analyze protein-protein interaction. Membrane-spanning proteins like plant receptor kinases find their way to the plasma membrane when expressed in yeast and seem to retain their structure and function. Here, we describe a general yeast DNA transformation procedure based on lithium acetate, salmon sperm DNA, and polyethylene glycol used to express recombinant proteins.

Molecular link between auxin and ROS-mediated polar growth.

Root hair polar growth is endogenously controlled by auxin and sustained by oscillating levels of reactive oxygen species (ROS). These cells extend several hundred-fold their original size toward signals important for plant survival. Although their final cell size is of fundamental importance, the molecular mechanisms that control it remain largely unknown.