Agarose imprints of plant cell surfaces for imaging.

Features of epidermal cells such as cell shape or arrangement of stomata are best studied under the scanning electron microscope. However, the preparation and viewing of samples using electron microscopy can be relatively laborious. A quick alternative is to view epidermal imprints in agarose using Nomarski differential-interference contrast microscopy.

The NGATHA genes direct style development in the Arabidopsis gynoecium.

The gynoecium is the most complex floral organ, designed to protect the ovules and ensure their fertilization. Correct patterning and tissue specification in the developing gynoecium involves the concerted action of a host of genetic factors. In addition, apical-basal patterning into different domains, stigma and style, ovary and gynophore, appears to depend on the establishment and maintenance of asymmetric auxin distribution, with an auxin maximum at the apex.

Clearing plant tissue for observation of vascular strands.

INTRODUCTIONVascular strands constitute an internal tissue that is important for plant growth. The strands are easily imaged by whole-mount analysis after fixation and tissue clearing, as described in this article.

Structural and functional insights into the regulation of Arabidopsis AGC VIIIa kinases.

The AGCVIIIa kinases of Arabidopsis are members of the eukaryotic PKA, PKG, and PKC group of regulatory kinases. One AGCVIIIa kinase, PINOID (PID), plays a fundamental role in the asymmetrical localization of membrane proteins during polar auxin transport. The remaining 16 AGCVIIIa genes have not been associated with single mutant phenotypes, suggesting that the corresponding kinases function redundantly.

Phosphorylation and activation of PINOID by the phospholipid signaling kinase 3-phosphoinositide-dependent protein kinase 1 (PDK1) in Arabidopsis.

Activity of the serine-threonine protein kinase PINOID (PID) has been implicated in the asymmetrical localization of the membrane-associated PINFORMED (PIN) family of auxin transport facilitators. However, the means by which PID regulates PIN protein distribution is unknown. We have used recombinant PID protein to dissect the regulation of PID activity in vitro.

Regulation of Arabidopsis shoot apical meristem and lateral organ formation by microRNA miR166g and its AtHD-ZIP target genes.

Plant development is characterized by precise control of gene regulation, leading to the correct spatial and temporal tissue patterning. We have characterized the Arabidopsis jabba-1D (jba-1D) mutant, which displays multiple enlarged shoot meristems, radialized leaves, reduced gynoecia and vascular defects. The jba-1D meristem phenotypes require WUSCHEL (WUS) activity, and correlate with a dramatic increase in WUS expression levels.

A homolog of prokaryotic thiol disulfide transporter CcdA is required for the assembly of the cytochrome b6f complex in Arabidopsis chloroplasts.

The c-type cytochromes are defined by the occurrence of heme covalently linked to the polypeptide via thioether bonds between heme and the cysteine sulfhydryls in the CXXCH motif of apocytochrome. Maintenance of apocytochrome sulfhydryls in a reduced state is a prerequisite for covalent ligation of heme to the CXXCH motif. In bacteria, a thiol disulfide transporter and a thioredoxin are two components in a thio-reduction pathway involved in c-type cytochrome assembly.

Protein phosphorylation in the delivery of and response to auxin signals.

The importance of reversible protein phosphorylation in regulation of plant growth and development has been amply demonstrated by decades of research. Here we discuss recent studies that suggest roles for protein phosphorylation in regulation of both auxin responses and polar auxin transport. Specific kinases act at auxin-requiring steps in floral and embryonic development, and at the junction(s) between light and auxin signaling pathways in hypocotyl elongation and phototropism responses.