Repressive ZINC FINGER OF ARABIDOPSIS THALIANA proteins promote programmed cell death in the Arabidopsis columella root cap.

Developmental programmed cell death (dPCD) controls a plethora of functions in plant growth and reproduction. In the root cap of Arabidopsis (Arabidopsis thaliana), dPCD functions to control organ size in balance with the continuous stem cell activity in the root meristem. Key regulators of root cap dPCD including SOMBRERO/ANAC033 (SMB) belong to the NAC family of transcription factors.

GR24, A Synthetic Strigolactone Analog, and Light Affect the Organization of Cortical Microtubules in Arabidopsis Hypocotyl Cells.

Strigolactones are plant hormones regulating cytoskeleton-mediated developmental events in roots, such as lateral root formation and elongation of root hairs and hypocotyls. The latter process was addressed herein by the exogenous application of a synthetic strigolactone, GR24, and an inhibitor of strigolactone biosynthesis, TIS108, on hypocotyls of wild-type Arabidopsis and a strigolactone signaling mutant . Owing to the interdependence between light and strigolactone signaling, the present work was extended to seedlings grown under a standard light/dark regime, or under continuous darkness.

HEAT SHOCK PROTEIN 90 proteins and YODA regulate main body axis formation during early embryogenesis.

The YODA (YDA) kinase pathway is intimately associated with the control of Arabidopsis (Arabidopsis thaliana) embryo development, but little is known regarding its regulators. Using genetic analysis, HEAT SHOCK PROTEIN 90 (HSP90) proteins emerge as potent regulators of YDA in the process of embryo development and patterning. This study is focused on the characterization and quantification of early embryonal traits of single and double hsp90 and yda mutants.

Complementary Superresolution Visualization of Composite Plant Microtubule Organization and Dynamics.

Microtubule bundling is an essential mechanism underlying the biased organization of interphase and mitotic microtubular systems of eukaryotes in ordered arrays. Microtubule bundle formation can be exemplified in plants, where the formation of parallel microtubule systems in the cell cortex or the spindle midzone is largely owing to the microtubule crosslinking activity of a family of microtubule associated proteins, designated as MAP65s. Among the nine members of this family in , MAP65-1 and MAP65-2 are ubiquitous and functionally redundant.

Multifaceted roles of HEAT SHOCK PROTEIN 90 molecular chaperones in plant development.

HEAT SHOCK PROTEINS 90 (HSP90s) are molecular chaperones that mediate correct folding and stability of many client proteins. These chaperones act as master molecular hubs involved in multiple aspects of cellular and developmental signalling in diverse organisms. Moreover, environmental and genetic perturbations affect both HSP90s and their clients, leading to alterations of molecular networks determining respectively plant phenotypes and genotypes and contributing to a broad phenotypic plasticity.

YODA-HSP90 Module Regulates Phosphorylation-Dependent Inactivation of SPEECHLESS to Control Stomatal Development under Acute Heat Stress in Arabidopsis.

Stomatal ontogenesis, patterning, and function are hallmarks of environmental plant adaptation, especially to conditions limiting plant growth, such as elevated temperatures and reduced water availability. The specification and distribution of a stomatal cell lineage and its terminal differentiation into guard cells require a master regulatory protein phosphorylation cascade involving the YODA mitogen-activated protein kinase kinase kinase. YODA signaling results in the activation of MITOGEN-ACTIVATED PROTEIN KINASEs (MPK3 and MPK6), which regulate transcription factors, including SPEECHLESS (SPCH).

Phosphorylation of Plant Microtubule-Associated Proteins During Cell Division.

Progression of mitosis and cytokinesis depends on the reorganization of cytoskeleton, with microtubules driving the segregation of chromosomes and their partitioning to two daughter cells. In dividing plant cells, microtubules undergo global reorganization throughout mitosis and cytokinesis, and with the aid of various microtubule-associated proteins (MAPs), they form unique systems such as the preprophase band (PPB), the acentrosomal mitotic spindle, and the phragmoplast. Such proteins include nucleators of microtubule formation, plus end binding proteins involved in the regulation of microtubule dynamics, crosslinking proteins underlying microtubule bundle formation and members of the kinesin superfamily with microtubule-dependent motor activities.