Cytokinins regulate spatially specific ethylene production to control root growth in Arabidopsis.

Two principal growth regulators, cytokinins and ethylene, are known to interact in the regulation of plant growth. However, information about the underlying molecular mechanism and positional specificity of cytokinin/ethylene crosstalk in the control of root growth is scarce. We have identified the spatial specificity of cytokinin-regulated root elongation and root apical meristem (RAM) size, both of which we demonstrate to be dependent on ethylene biosynthesis.

Hormonal orchestration of root apical meristem formation and maintenance in Arabidopsis.

Plant hormones are key regulators of a number of developmental and adaptive responses in plants, integrating the control of intrinsic developmental regulatory circuits with environmental inputs. Here we provide an overview of the molecular mechanisms underlying hormonal regulation of root development. We focus on key events during both embryonic and post-embryonic development, including specification of the hypophysis as a future organizer of the root apical meristem (RAM), hypophysis asymmetric division, specification of the quiescent centre (QC) and the stem cell niche (SCN), RAM maturation and maintenance of QC/SCN activity, and RAM size.

ETR1 Integrates Response to Ethylene and Cytokinins into a Single Multistep Phosphorelay Pathway to Control Root Growth.

Cytokinins and ethylene control plant development via sensors from the histidine kinase (HK) family. However, downstream signaling pathways for the key phytohormones are distinct. Here we report that not only cytokinin but also ethylene is able to control root apical meristem (RAM) size through activation of the multistep phosphorelay (MSP) pathway.

Illuminating light, cytokinin, and ethylene signalling crosstalk in plant development.

Integrating important environmental signals with intrinsic developmental programmes is a crucial adaptive requirement for plant growth, survival, and reproduction. Key environmental cues include changes in several light variables, while important intrinsic (and highly interactive) regulators of many developmental processes include the phytohormones cytokinins (CKs) and ethylene. Here, we discuss the latest discoveries regarding the molecular mechanisms mediating CK/ethylene crosstalk at diverse levels of biosynthetic and metabolic pathways and their complex interactions with light.

Proteome analysis in Arabidopsis reveals shoot- and root-specific targets of cytokinin action and differential regulation of hormonal homeostasis.

The plant hormones cytokinins (CKs) regulate multiple developmental and physiological processes in Arabidopsis (Arabidopsis thaliana). Responses to CKs vary in different organs and tissues (e.g.

Physiological and proteomic approaches to evaluate the role of sterol binding in elicitin-induced resistance.

Cryptogein is a proteinaceous elicitor secreted by Phytophthora cryptogea that can induce resistance to P. parasitica in tobacco plants. On the basis of previous computer modelling experiments, by site-directed mutagenesis a series of cryptogein variants was prepared with altered abilities to bind sterols, phospholipids or both.