Biological Resources and Post-harvest Division, Japan International Research Center for Agricultural Sciences, Tsukuba, Ibaraki 305–8686, Japan (K.M., K.Y., K.Y.-S.); Gene Discovery Research Group, RIKEN Center for Sustainable Resource Science, Tsukuba, Ibaraki 305–0074, Japan (K.U., K.Sa., K.Sh.); Department of Biotechnology Research, Kazusa DNA Research Institute, Kisarazu, Chiba 292–0818, Ja...

Plants depend on the signalling of the phytohormone auxin for their development and for responding to environmental perturbations. The associated biomolecular signalling network involves a negative feedback on Aux/IAA proteins which mediate the influence of auxin (the signal) on the auxin response factor (ARF) transcription factors (the drivers of the response). To probe the role of this feedba...

We present here the complete genome sequence of Bradyrhizobium japonicum strain E109, one of the most used rhizobacteria for soybean inoculation in Argentina since the 1970s. The genome consists of a 9.22-Mbp single chromosome and contains several genes related to nitrogen fixation, phytohormone biosynthesis, and a rhizospheric lifestyle.

Cytokinins are ubiquitous plant hormones that have dramatic effects on growth and development, but almost nothing is known of their molecular mode of action. Recently, evidence has emerged that cytokinin action may involve a G-protein-coupled receptor and/or a two-component signaling pathway.

New plant growth regulators, named citrinolactones A (1), B (2) and C (3) and sclerotinin C (4), were isolated from Penicillium citrinum and their structures established by spectroscopic methods including 2D NMR. Compounds 1 and 4 increased root growth in proportion to their concentration from 3 to 300 mg/l. In contrast, 2 completely inhibited root growth at a concentration of 300 mg/l and 3 di...

The plant hormone abscisic acid (ABA) regulates the aperture of the stomatal pore. The recent identification of new intermediates involved in ABA signaling suggests that this complex pathway is organized as a module-based network.

A striking phenomenon unique to the kingdom of plants is the regular arrangement of lateral organs around a central axis, known as phyllotaxis. Recent molecular-genetic experiments indicate that active transport of the plant hormone auxin is the key process regulating phyllotaxis. A conceptual model based on these experiments, introduced by Reinhardt et al. [Reinhardt, D., Pesce, E. R., Stieger...

A better understanding of the development and architecture of roots is essential to develop strategies to increase crop yield and optimize agricultural land use. Roots control nutrient and water uptake, provide anchoring and mechanical support and can serve as important storage organs. Root growth and development is under tight genetic control and modulated by developmental cues including plant...

The evidence that FLOWERING LOCUS T (FT) protein, and its paralog TWIN SISTER OF FT, act as the long-distance floral stimulus, or at least that they are part of it in diverse plant species, has attracted much attention in recent years. Studies to understand the physiological and molecular apparatuses that integrate spatial and temporal signals to regulate developmental transitions in plants have...

The Cholodny-Went hypothesis holds that gravitropic curvature of a growing plant organ depends on regulated transport of the plant hormone auxin; new studies of the agravitropic mutant aux1 of Arabidopsis provide strong evidence in support of this hypothesis.