A Model of the Full-Length Cytokinin Receptor: New Insights and Prospects.

Cytokinins (CK) are one of the most important classes of phytohormones that regulate a wide range of processes in plants. A CK receptor, a sensor hybrid histidine kinase, was discovered more than 20 years ago, but the structural basis for its signaling is still a challenge for plant biologists. To date, only two fragments of the CK receptor structure, the sensory module and the receiver domain, were experimentally resolved.

The cytokinin receptor OHK4/OsHK4 regulates inflorescence architecture in rice via an IDEAL PLANT ARCHITECTURE1/WEALTHY FARMER'S PANICLE-mediated positive feedback circuit.

Inflorescence architecture is important for rice (Oryza sativa) grain yield. The phytohormone cytokinin (CK) has been shown to regulate rice inflorescence development; however, the underlying mechanism mediated by CK perception is still unclear. Employing a forward genetic approach, we isolated an inactive variant of the CK receptor OHK4/OsHK4 gene named panicle length1, which shows decreased panicle size due to reduced inflorescence meristem (IM) activity.

Canonical and Alternative Auxin Signaling Systems in Mono-, Di-, and Tetraploid Potatoes.

It has long been known that the phytohormone auxin plays a promoting role in tuber formation and stress tolerance in potatoes. Our study aimed to identify and characterize the complete sets of auxin-related genes that presumably constitute the entire auxin signaling system in potato ( L.).

In Planta, In Vitro and In Silico Studies of Chiral -Benzyladenine Derivatives: Discovery of Receptor-Specific -Enantiomers with Cytokinin or Anticytokinin Activities.

Cytokinins, classical phytohormones, affect all stages of plant ontogenesis, but their application in agriculture is limited because of the lack of appropriate ligands, including those specific for individual cytokinin receptors. In this work, a series of chiral -benzyladenine derivatives were studied as potential cytokinins or anticytokinins. All compounds contained a methyl group at the α-carbon atom of the benzyl moiety, making them - or -enantiomers.

Cytokinin Perception in Ancient Plants beyond Angiospermae.

Cytokinins (CKs) control many plant developmental processes and responses to environmental cues. Although the CK signaling is well understood, we are only beginning to decipher its evolution. Here, we investigated the CK perception apparatus in early-divergent plant species such as bryophyte , lycophyte , and gymnosperm .

Global View on the Cytokinin Regulatory System in Potato.

Cytokinins (CKs) were earlier shown to promote potato tuberization. Our study aimed to identify and characterize CK-related genes which constitute CK regulatory system in the core potato () genome. For that, CK-related genes were retrieved from the sequenced genome of the doubled monoploid (DM) Phureja group, classified and compared with Arabidopsis orthologs.

Modeling of Protein⁻Protein Interactions in Cytokinin Signal Transduction.

The signaling of cytokinins (CKs), classical plant hormones, is based on the interaction of proteins that constitute the multistep phosphorelay system (MSP): catalytic receptors-sensor histidine kinases (HKs), phosphotransmitters (HPts), and transcription factors-response regulators (RRs). Any CK receptor was shown to interact in vivo with any of the studied HPts and . In addition, both of these proteins tend to form a homodimer or a heterodimeric complex with protein-paralog.

Auxins in potato: molecular aspects and emerging roles in tuber formation and stress resistance.

The study of the effects of auxins on potato tuberization corresponds to one of the oldest experimental systems in plant biology, which has remained relevant for over 70 years. However, only recently, in the postgenomic era, the role of auxin in tuber formation and other vital processes in potatoes has begun to emerge. This review describes the main results obtained over the entire period of auxin-potato research, including the effects of exogenous auxin; the content and dynamics of endogenous auxins; the effects of manipulating endogenous auxin content; the molecular mechanisms of auxin signaling, transport and inactivation; the role and position of auxin among other tuberigenic factors; the effects of auxin on tuber dormancy; the prospects for auxin use in potato biotechnology.

Cytokinin perception in potato: new features of canonical players.

Potato is the most economically important non-cereal food crop. Tuber formation in potato is regulated by phytohormones, cytokinins (CKs) in particular. The present work studied CK signal perception in potato.

Studies of cytokinin receptor-phosphotransmitter interaction provide evidences for the initiation of cytokinin signalling in the endoplasmic reticulum.

Cytokinin receptors were shown recently to be localised mainly to the endoplasmic reticulum (ER); however, the activity of ER-located receptors was not proven. We have therefore tested the functionality of ER-located Arabidopsis receptors. The first step of cytokinin signal transduction is the transfer of a phosphoryl group from the activated receptor to a phosphotransfer protein.

Plant membrane assays with cytokinin receptors underpin the unique role of free cytokinin bases as biologically active ligands.

Cytokinin receptors play a key role in cytokinin-dependent processes regulating plant growth, development, and adaptation; therefore, the functional properties of these receptors are of great importance. Previously the properties of cytokinin receptors were investigated in heterologous assay systems using unicellular microorganisms, mainly bacteria, expressing receptor proteins. However, within microorganisms receptors reside in an alien environment that might distort the receptor properties.