The plant hormone IAA (or auxin) is central to the control of plant growth and development. Processes governed by auxin in concert with other plant growth regulators include development of vascular tissues, formation of lateral and adventitious roots, control of apical dominance, and tropic responses (Went and Thimann, 1937). At the leve1 of cellular physiology, auxin profoundly affects turgor,...

Plant hormones have pivotal roles in the regulation of plant growth, development, and reproduction. Additionally, they emerged as cellular signal molecules with key functions in the regulation of immune responses to microbial pathogens, insect herbivores, and beneficial microbes. Their signaling pathways are interconnected in a complex network, which provides plants with an enormous regulatory ...

Auxin is a central hormone that exerts pleiotropic effects on plant growth including the development of roots, shoots, flowers and fruit. The perception and signaling of the plant hormone auxin rely on the cooperative action of several components, among which auxin/indole-3-acetic acid (Aux/IAA) proteins play a pivotal role. In this study, we identified and comprehensively analyzed the entire A...

For years, many plant science researchers who study the genetic programming that determines structural organization and reproductive processes self-identified as developmental biologists, while those studying plant responses to the environment identified as plant physiologists. Plant hormones such as auxins, cytokinins, and gibberellic acids that function as developmental messengers were viewed...

1. Sections of Avena coleoptiles are found to show a considerable elongation when suspended in solutions of growth substance. 2. This elongation does not take place in the absence of O(2) and is inhibited by KCN and phenylurethane. 3. The rate of respiration of sections of coleoptiles is increased by the addition of growth substance in concentrations which cause growth. High concentrations of g...

The rice (Oryza sativa L.) homeobox gene OSH1 causes morphological alterations when ectopically expressed in transgenic rice, Arabidopsis thaliana, and tobacco (Nicotiana tabacum L.) and is therefore believed to function as a morphological regulator gene. To determine the relationship between OSH1 expression and morphological alterations, we analyzed the changes in hormone levels in transgenic ...

The plant-pathogen interaction is a multifactor process that may lead to resistance or susceptible responses of plant to pathogens. During the arms race between plant and pathogens, various biochemical, molecular and physiological events are triggered in plant cells such as ROS signaling, hormone activation and gene expression reprogramming. In plants, microRNAs (miRNAs) are key post-transcript...

Classically, hormones elicit specific cellular responses by activating dedicated receptors. Nevertheless, the biosynthesis and turnover of many of these hormone molecules also produce chemically related metabolites. These molecules may also possess hormonal activities; therefore, one or more may contribute to the adaptive plasticity of signaling outcomes in host organisms. Here, we show that a ...

The remarkable plasticity of plant ontogeny is shaped by hormone pathways, which not only orchestrate intrinsic developmental programs, but also convey environmental inputs. Several classes of plant hormones exist, and among them auxin, brassinosteroid and gibberellin are central for the regulation of growth in general and of cell elongation in particular. Various growth phenomena can be modula...