ATL8, a RING E3 ligase, modulates root growth and phosphate homeostasis in Arabidopsis.

Ubiquitination-mediated post-translational modification of proteins is a pivotal regulatory mechanism involved in the growth and development of the plant. The Arabidopsis Tóxicos en Levadura (ATL) family is a group of RING-type ubiquitin ligases (E3) and ATL8 is a membrane-localized protein. Here, a reverse genetics approach was used to elucidate the role of ATL8 in phosphate (Pi) homeostasis.

The Phosphate Fast-Responsive Genes and Affect Phosphocholine and Phosphoethanolamine Content.

Phosphate starvation-mediated induction of the HAD-type phosphatases PPsPase1 (AT1G73010) and PECP1 (AT1G17710) has been reported in Arabidopsis (). However, little is known about their in vivo function or impact on plant responses to nutrient deficiency. The preferences of PPsPase1 and PECP1 for different substrates have been studied in vitro but require confirmation in planta.

Arabidopsis MYB-Related HHO2 Exerts a Regulatory Influence on a Subset of Root Traits and Genes Governing Phosphate Homeostasis.

Phosphate (Pi), an essential macronutrient required for growth and development of plants, is often limiting in soils. Pi deficiency modulates the expression of Pi starvation-responsive (PSR) genes including transcription factors (TFs). Here, we elucidated the role of the MYB-related TF HYPERSENSITIVITY TO LOW PHOSPHATE-ELICITED PRIMARY ROOT SHORTENING1 HOMOLOG2 (HHO2, At1g68670) in regulating Pi acquisition and signaling in Arabidopsis thaliana HHO2 was specifically and significantly induced in different tissues in response to Pi deprivation.

Arabidopsis thaliana mutant lpsi reveals impairment in the root responses to local phosphate availability.

Phosphate (Pi) deficiency triggers local Pi sensing-mediated inhibition of primary root growth and development of root hairs in Arabidopsis (Arabidopsis thaliana). Generation of activation-tagged T-DNA insertion pools of Arabidopsis expressing the luciferase gene (LUC) under high-affinity Pi transporter (Pht1;4) promoter, is an efficient approach for inducing genetic variations that are amenable for visual screening of aberrations in Pi deficiency responses. Putative mutants showing altered LUC expression during Pi deficiency were identified and screened for impairment in local Pi deficiency-mediated inhibition of primary root growth.

Ethylene Response Factor070 regulates root development and phosphate starvation-mediated responses.

Inorganic phosphate (Pi) availability is a major factor determining growth and consequently the productivity of crops. However, it is one of the least available macronutrients due to its high fixation in the rhizospheres. To overcome this constraint, plants have developed adaptive responses to better acquire, utilize, and recycle Pi.

Transcriptional regulation of phosphate acquisition by higher plants.

Phosphorus (P), an essential macronutrient required for plant growth and development, is often limiting in natural and agro-climatic environments. To cope with heterogeneous or low phosphate (Pi) availability, plants have evolved an array of adaptive responses facilitating optimal acquisition and distribution of Pi. The root system plays a pivotal role in Pi-deficiency-mediated adaptive responses that are regulated by a complex interplay of systemic and local Pi sensing.

Arabidopsis Pht1;5 plays an integral role in phosphate homeostasis.

The mobilization of inorganic phosphate (Pi) in planta is a complex process regulated by a number of developmental and environmental cues. Plants possess many Pi transporters that acquire Pi from the rhizosphere and translocate it throughout the plant. A few members of the high-affinity Pht1 family of Pi transporters have been functionally characterized and, for the most part, have been shown to be involved in Pi acquisition.

Characterization of the phosphate starvation-induced glycerol-3-phosphate permease gene family in Arabidopsis.

Phosphate (Pi) deficiency is one of the leading causes of loss in crop productivity. Plants respond to Pi deficiency by increasing Pi acquisition and remobilization involving organic and inorganic Pi transporters. Here, we report the functional characterization of a putative organic Pi transporter, Glycerol-3-phosphate permease (G3Pp) family, comprising five members (AtG3Pp1 to -5) in Arabidopsis (Arabidopsis thaliana).

Arabidopsis Pht1;5 mobilizes phosphate between source and sink organs and influences the interaction between phosphate homeostasis and ethylene signaling.

Phosphorus (P) remobilization in plants is required for continuous growth and development. The Arabidopsis (Arabidopsis thaliana) inorganic phosphate (Pi) transporter Pht1;5 has been implicated in mobilizing stored Pi out of older leaves. In this study, we used a reverse genetics approach to study the role of Pht1;5 in Pi homeostasis.

Genetic and genomic evidence that sucrose is a global regulator of plant responses to phosphate starvation in Arabidopsis.

Plants respond to phosphate (Pi) starvation by exhibiting a suite of developmental, biochemical, and physiological changes to cope with this nutritional stress. To understand the molecular mechanism underlying these responses, we isolated an Arabidopsis (Arabidopsis thaliana) mutant, hypersensitive to phosphate starvation1 (hps1), which has enhanced sensitivity in almost all aspects of plant responses to Pi starvation. Molecular and genetic analyses indicated that the mutant phenotype is caused by overexpression of the SUCROSE TRANSPORTER2 (SUC2) gene.

Ethylene signalling is involved in regulation of phosphate starvation-induced gene expression and production of acid phosphatases and anthocyanin in Arabidopsis.

• With the exception of root hair development, the role of the phytohormone ethylene is not clear in other aspects of plant responses to inorganic phosphate (Pi) starvation. • The induction of AtPT2 was used as a marker to find novel signalling components involved in plant responses to Pi starvation. Using genetic and chemical approaches, we examined the role of ethylene in the regulation of plant responses to Pi starvation.

Histone H2A.Z regulates the expression of several classes of phosphate starvation response genes but not as a transcriptional activator.

Phosphate (Pi) availability is a major constraint to plant growth. Consequently, plants have evolved complex adaptations to tolerate low Pi conditions. Numerous genes implicated in these adaptations have been identified, but their chromatin-level regulation has not been investigated.

The phosphate transporter PHT4;6 is a determinant of salt tolerance that is localized to the Golgi apparatus of Arabidopsis.

Insertion mutations that disrupt the function of PHT4;6 (At5g44370) cause NaCl hypersensitivity of Arabidopsis seedlings that is characterized by reduced growth of the primary root, enhanced lateral branching, and swelling of root tips. Mutant phenotypes were exacerbated by sucrose, but not by equiosmolar concentrations of mannitol, and attenuated by low inorganic phosphate in the medium. Protein PHT4;6 belongs to the Major Facilitator Superfamily of permeases that shares significant sequence similarity to mammalian type-I Pi transporters and vesicular glutamate transporters, and is a member of the PHT4 family of putative intracellular phosphate transporters of plants.

Phosphate starvation responses and gibberellic acid biosynthesis are regulated by the MYB62 transcription factor in Arabidopsis.

The limited availability of phosphate (Pi) in most soils results in the manifestation of Pi starvation responses in plants. To dissect the transcriptional regulation of Pi stress-response mechanisms, we have characterized the biological role of MYB62, an R2R3-type MYB transcription factor that is induced in response to Pi deficiency. The induction of MYB62 is a specific response in the leaves during Pi deprivation.

Promoter deletion analysis elucidates the role of cis elements and 5'UTR intron in spatiotemporal regulation of AtPht1;4 expression in Arabidopsis.

The high-affinity phosphate transporter AtPht1;4 (Arabidopsis phosphate transporter1;4) is not only induced in response to inorganic phosphate (Pi) starvation but also preferentially expressed in the roots of Arabidopsis. In this study, we carried out AtPht1;4 promoter deletion analysis to identify regions that control the Pi responsiveness and spatiotemporal expression of the gene. Expression cassettes with truncated promoter fragments cloned to GUS (beta-glucuronidase) coding sequence were developed.

Variations in the composition of gelling agents affect morphophysiological and molecular responses to deficiencies of phosphate and other nutrients.

Low inorganic phosphate (Pi) availability triggers an array of spatiotemporal adaptive responses in Arabidopsis (Arabidopsis thaliana). There are several reports on the effects of Pi deprivation on the root system that have been attributed to different growth conditions and/or inherent genetic variability. Here we show that the gelling agents, largely treated as inert components, significantly affect morphophysiological and molecular responses of the seedlings to deficiencies of Pi and other nutrients.

The effect of iron on the primary root elongation of Arabidopsis during phosphate deficiency.

Root architecture differences have been linked to the survival of plants on phosphate (P)-deficient soils, as well as to the improved yields of P-efficient crop cultivars. To understand how these differences arise, we have studied the root architectures of P-deficient Arabidopsis (Arabidopsis thaliana Columbia-0) plants. A striking aspect of the root architecture of these plants is that their primary root elongation is inhibited when grown on P-deficient medium.

Biochemical and molecular analysis of LePS2;1: a phosphate starvation induced protein phosphatase gene from tomato.

Adaptation of plants to phosphate (Pi) deficiency is a complex process involving host of biochemical changes. These changes are integrated at transcriptional level by Pi starvation mediated signal transduction pathway. Many of the signaling processes are regulated by reversible protein phosphorylation directed by protein kinases and protein phosphatases.

Transcriptional Regulation of Pi Starvation Responses by WRKY75.

Adaptive responses during phosphate (Pi) starvation are regulated by complex molecular mechanisms in plants. Transcription factors are believed to be the key determinants of Pi starvation responses. We have recently identified the plant-specific WRKY75 transcription factor as an important component of the Pi stress responses.

Phosphate homeostasis and root development in Arabidopsis are synchronized by the zinc finger transcription factor ZAT6.

Phosphorus availability is limited in many natural ecosystems. Plants adapt to phosphate (Pi) deficiency by complex molecular processes. There is growing evidence suggesting that transcription factors are key components in the regulation of these processes.

Phosphate differentially regulates 14-3-3 family members and GRF9 plays a role in Pi-starvation induced responses.

The 14-3-3s are phosphoserine-binding proteins that act as key regulators of many metabolic pathways. Several biotic and abiotic stresses have been shown to modulate the expression of 14-3-3 genes. In Arabidopsis thaliana, 15 genes are known to code for 14-3-3 isoforms belonging to epsilon and non-epsilon groups.

Functional characterization of LePT4: a phosphate transporter in tomato with mycorrhiza-enhanced expression.

Many plant roots acquire inorganic phosphate (Pi) from soils directly through the root-soil interface via high-affinity Pi transporters and/or through symbiotic associations between the cortical cells and arbuscular mycorrhizal fungi. In tomato, three phosphate transporters (LePT3, LePT4, and LePT5) are up-regulated upon colonization by arbuscular mycorrhizal fungi. In this study, the role of LePT4 in tomato is elucidated by molecular and physiological characterizations of a loss-of-function mutant lept4.

Differential effects of sucrose and auxin on localized phosphate deficiency-induced modulation of different traits of root system architecture in Arabidopsis.

Phosphorus, one of the essential elements for plants, is often a limiting nutrient in soils. Low phosphate (Pi) availability induces sugar-dependent systemic expression of genes and modulates the root system architecture (RSA). Here, we present the differential effects of sucrose (Suc) and auxin on the Pi deficiency responses of the primary and lateral roots of Arabidopsis (Arabidopsis thaliana).

WRKY75 transcription factor is a modulator of phosphate acquisition and root development in Arabidopsis.

Phosphate (Pi) deficiency limits plant growth and development, resulting in adaptive stress responses. Among the molecular determinants of Pi stress responses, transcription factors play a critical role in regulating adaptive mechanisms. WRKY75 is one of several transcription factors induced during Pi deprivation.

Phosphate starvation responses are mediated by sugar signaling in Arabidopsis.

Phosphate (Pi) is one of the least available plant nutrients in soils. It is associated with dynamic changes in carbon fluxes and several crucial processes that regulate plant growth and development. Pi levels regulate the expression of large number of genes including those involved in photosynthesis and carbon metabolism.