The Arabidopsis PIP1;1 Aquaporin Represses Lateral Root Development and Nitrate Uptake Under Low Nitrate Availability.

Nitrate (NO ) deficiency decreases root water uptake and root hydraulic conductance. This adaptive response is correlated with reduced abundance and activity of plasma membrane intrinsic protein (PIP) aquaporins. We therefore screened changes in the root architecture of a complete set of Arabidopsis pip loss-of-function mutants grown under NO deficiency to systematically approach the impact of PIPs under these conditions.

Distinct early transcriptional regulations by turgor and osmotic potential in the roots of Arabidopsis.

In a context of climate change, deciphering signaling pathways driving plant adaptation to drought, changes in water availability, and salt is key. A crossing point of these plant stresses is their impact on plant water potential (Ψ), a composite physico-chemical variable reflecting the availability of water for biological processes such as plant growth and stomatal aperture. The Ψ of plant cells is mainly driven by their turgor and osmotic pressures.

pin2 mutant agravitropic root phenotype is conditional and nutrient-sensitive.

Plants have the capacity to sense and adapt to environmental factors using the phytohormone auxin as a major regulator of tropism and development. Among these responses, gravitropism is essential for plant roots to grow downward in the search for nutrients and water. We discovered a new mutant allele of the auxin efflux transporter PIN2 that revealed that pin2 agravitropic root mutants are conditional and nutrient-sensitive.

High-throughput and automatic structural and developmental root phenotyping on Arabidopsis seedlings.

Background: High-throughput phenotyping is crucial for the genetic and molecular understanding of adaptive root system development. In recent years, imaging automata have been developed to acquire the root system architecture of many genotypes grown in Petri dishes to explore the Genetic x Environment (GxE) interaction. There is now an increasing interest in understanding the dynamics of the adaptive responses, such as the organ apparition or the growth rate.

Root Membrane Ubiquitinome under Short-Term Osmotic Stress.

Osmotic stress can be detrimental to plants, whose survival relies heavily on proteomic plasticity. Protein ubiquitination is a central post-translational modification in osmotic-mediated stress. In this study, we used the K-Ɛ-GG antibody enrichment method integrated with high-resolution mass spectrometry to compile a list of 719 ubiquitinated lysine (K-Ub) residues from 450 Arabidopsis root membrane proteins (58% of which are transmembrane proteins), thereby adding to the database of ubiquitinated substrates in plants.

Responses to Systemic Nitrogen Signaling in Arabidopsis Roots Involve -Zeatin in Shoots.

Plants face temporal and spatial variation in nitrogen (N) availability. This includes heterogeneity in soil nitrate (NO) content. To overcome these constraints, plants modify their gene expression and physiological processes to optimize N acquisition.

Evolution of sex chromosomes prior to speciation in the dioecious Phoenix species.

Understanding the driving forces and molecular processes underlying dioecy and sex chromosome evolution, leading from hermaphroditism to the occurrence of male and female individuals, is of considerable interest in fundamental and applied research. The genus Phoenix, belonging to the Arecaceae family, consists uniquely of dioecious species. Phylogenetic data suggest that the genus Phoenix has diverged from a hermaphroditic ancestor which is also shared with its closest relatives.

The Casuarina NIN gene is transcriptionally activated throughout Frankia root infection as well as in response to bacterial diffusible signals.

Root nodule symbioses (RNS) allow plants to acquire atmospheric nitrogen by establishing an intimate relationship with either rhizobia, the symbionts of legumes or Frankia in the case of actinorhizal plants. In legumes, NIN (Nodule INception) genes encode key transcription factors involved in nodulation. Here we report the characterization of CgNIN, a NIN gene from the actinorhizal tree Casuarina glauca using both phylogenetic analysis and transgenic plants expressing either ProCgNIN::reporter gene fusions or CgNIN RNAi constructs.

Inhibition of auxin signaling in Frankia species-infected cells in Casuarina glauca nodules leads to increased nodulation.

Actinorhizal symbioses are mutualistic interactions between plants and the soil bacteria Frankia spp. that lead to the formation of nitrogen-fixing root nodules. The plant hormone auxin has been suggested to play a role in the mechanisms that control the establishment of this symbiosis in the actinorhizal tree Casuarina glauca.

Identification of potential transcriptional regulators of actinorhizal symbioses in Casuarina glauca and Alnus glutinosa.

Background: Trees belonging to the Casuarinaceae and Betulaceae families play an important ecological role and are useful tools in forestry for degraded land rehabilitation and reforestation. These functions are linked to their capacity to establish symbiotic relationships with a nitrogen-fixing soil bacterium of the genus Frankia. However, the molecular mechanisms controlling the establishment of these symbioses are poorly understood.

Heart of endosymbioses: transcriptomics reveals a conserved genetic program among arbuscular mycorrhizal, actinorhizal and legume-rhizobial symbioses.

To improve their nutrition, most plants associate with soil microorganisms, particularly fungi, to form mycorrhizae. A few lineages, including actinorhizal plants and legumes are also able to interact with nitrogen-fixing bacteria hosted intracellularly inside root nodules. Fossil and molecular data suggest that the molecular mechanisms involved in these root nodule symbioses (RNS) have been partially recycled from more ancient and widespread arbuscular mycorrhizal (AM) symbiosis.

Auxin carriers localization drives auxin accumulation in plant cells infected by Frankia in Casuarina glauca actinorhizal nodules.

Actinorhizal symbioses are mutualistic interactions between plants and the soil bacteria Frankia that lead to the formation of nitrogen-fixing root nodules. Little is known about the signaling mechanisms controlling the different steps of the establishment of the symbiosis. The plant hormone auxin has been suggested to play a role.