Phosphate Starvation Inducible Metabolism in <i>Lycopersicon esculentum</i>

Goldstein, Alan H.; Mayfield, Stephen P.; Danon, Avihai; Tibbot, Brian K.

doi:10.1104/pp.91.1.175

Cited by 32 publications

(12 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Likewise, the increase in Pi uptake rate by the AlF x -pretreated roots correlates well with the profile exhibited by Pi-starved roots ( Fig. 5; see also data from Clarkson and Scattergood, 1982;Goldstein et al, 1989) and is consistent with the time required for induction of phosphate transporter proteins in response to Pi starvation (Muchhal and Raghothama, 1999).…”

Section: Physiological Considerationsupporting

confidence: 74%

Inhibition of Phosphate Uptake in Corn Roots by Aluminum-Fluoride Complexes

Façanha

Okorokova‐Façanha

2002

Plant Physiology

View full text Add to dashboard Cite

F forms stable complexes with Al at conditions found in the soil. Fluoroaluminate complexes (AlFx) have been widely described as effective analogs of inorganic phosphate (Pi) in Pi-binding sites of several proteins. In this work, we explored the possibility that the phytotoxicity of AlFx reflects their activity as Pi analogs. For this purpose, 32P-labeled phosphate uptake by excised roots and plasma membrane H+-ATPase activity were investigated in an Al-tolerant variety of maize (Zea mays L. var. dwarf hybrid), either treated or not with AlFx. In vitro, AlFx competitively inhibited the rate of root phosphate uptake as well as the H+-ATPase activity. Conversely, pretreatment of seedlings with AlFxin vivo promoted no effect on the H+-ATPase activity, whereas a biphasic effect on Pi uptake by roots was observed. Although the initial rate of phosphate uptake by roots was inhibited by AlFx pretreatment, this situation changed over the following minutes as the rate of uptake increased and a pronounced stimulation in subsequent 32Pi uptake was observed. This kinetic behavior suggests a reversible and competitive inhibition of the phosphate transporter by fluoroaluminates. The stimulation of root32Pi uptake induced by AlFx pretreatment was tentatively interpreted as a phosphate starvation response. This report places AlF3 and AlF4 − among Al-phytotoxic species and suggests a mechanism of action where the accumulation of Pi-mimicking fluoroaluminates in the soil may affect the phosphate absorption by plants. The biochemical, physiological, and environmental significance of these findings is discussed.

show abstract

Section: Physiological Considerationsupporting

confidence: 74%

Inhibition of Phosphate Uptake in Corn Roots by Aluminum-Fluoride Complexes

Façanha

Okorokova‐Façanha

2002

Plant Physiology

View full text Add to dashboard Cite

show abstract

“…SDS-PAGE analyses have revealed that the CCF of +Pi, )Pi, and Pi-resupplied tomato suspension cells contain up to 50 different polypeptides, several of which are unique to )Pi cultures [20,24] (also this study, not shown). This suggests that the pair of Pi-inducible secreted serine protease isoforms of cultured tomato cells (Fig.…”

Section: Discussionsupporting

confidence: 59%

Phosphate or phosphite addition promotes the proteolytic turnover of phosphate‐starvation inducible tomato purple acid phosphatase isozymes

2004

View full text Add to dashboard Cite

Within 48 h of the addition of 2.5 mM phosphate (HPO 2À 4 , Pi) or phosphite (H 2 PO À 3 , Phi) to 8-day-old Pi-starved ()Pi) tomato suspension cells: (i) secreted and intracellular purple acid phosphatase (PAP) activities decreased by about 12-and 6-fold, respectively and (ii) immunoreactive PAP polypeptides either disappeared (secreted PAPs) or were substantially reduced (intracellular PAP). The degradation of both secreted PAP isozymes was correlated with the de novo synthesis of two extracellular serine proteases having M r s of 137 and 121 kDa. In vitro proteolysis of purified secreted tomato PAP isozymes occurred following their 24 h incubation with culture filtrate from Pi-resupplied cells. The results indicate that Pi or Phi addition to )Pi tomato cells induces serine proteases that degrade Pi-starvation inducible extracellular proteins.

show abstract

“…Inducible expression of P i transporters is vital for growth of plants under varying concentrations of P i . The induction of LePT1 protein in response to P i starvation correlates with the observed increase in P i uptake rate of roots and cell cultures (27,31). Addition of protein synthesis inhibitors suppressed P i starvation-induced P i uptake in tobacco cell cultures, indicating that de novo synthesis of P i transporters is required for the transport process (28).…”

Section: Discussionmentioning

confidence: 57%

Transcriptional regulation of plant phosphate transporters

Muchhal

Raghothama²

1999

Proc. Natl. Acad. Sci. U.S.A.

167

125

View full text Add to dashboard Cite

Phosphorus is acquired by plant roots primarily via the high-affinity inorganic phosphate (P i ) transporters. The transcripts for P i transporters are highly inducible upon P i starvation, which also results in enhanced P i uptake when P i is resupplied. Using antibodies specific to one of the tomato P i transporters (encoded by LePT1), we show that an increase in the LePT1 transcript under P i starvation leads to a concurrent increase in the transporter protein, suggesting a transcriptional regulation for P i acquisition. LePT1 protein accumulates rapidly in tomato roots in response to P i starvation. The level of transporter protein accumulation depends on the P i concentration in the medium, and it is reversible upon resupply of P i . LePT1 protein accumulates all along the roots under P i starvation and is localized primarily in the plasma membranes. These results clearly demonstrate that plants increase their capacity for P i uptake during P i starvation by synthesis of additional transporter molecules.Phosphorus availability is considered one of the major factors that limits growth of plants in natural ecosystems. The concentration of available phosphorus is generally in the micromolar range, which is below that of many micronutrients (1). Consequently plants have developed several adaptive mechanisms to overcome P i deficiency. These include changes in root growth and architecture, increased production of phosphatases and RNases, altered activity of several enzymes of the glycolytic pathway (2, 3), and an increased P i uptake rate of roots (4). The ultimate consequences of these modifications are increased P i availability in the rhizosphere and enhanced uptake.Phosphorus is acquired by the plant roots in an energymediated cotransport process driven by a proton gradient generated by plasma membrane H ϩ -ATPases (5). The kinetic characterization of the P i -uptake system by whole plants and cultured cells indicates a high-affinity transport activity operating at low concentrations (micromolar range) and a lowaffinity activity operating at higher concentrations. The very low concentration (micromolar) of P i in soil solution suggests that high-affinity transporters are primarily involved in P i uptake by plants (3). The low-affinity system is apparently expressed constitutively, whereas the high-affinity system is induced under P i deficiency (6). The induction process appears to involve de novo protein synthesis, since inhibitors of protein synthesis drastically reduce the induction of high-affinity P i transport. The increased synthesis of a high-affinity carrier system has been proposed to be responsible for enhanced P i uptake observed under P i -deficiency conditions (6).High-affinity P i transporter genes have been cloned and characterized from fungi and from several plant species, including Arabidopsis, tomato, potato, Medicago, and Catharanthus (7). All the cloned P i transporters are integral membrane proteins containing 12 membrane-spanning regions, separated into two groups of 6 by a lar...

show abstract

Phosphate Starvation Inducible Metabolism in Lycopersicon esculentum

Cited by 32 publications

References 16 publications

Inhibition of Phosphate Uptake in Corn Roots by Aluminum-Fluoride Complexes

Inhibition of Phosphate Uptake in Corn Roots by Aluminum-Fluoride Complexes

Phosphate or phosphite addition promotes the proteolytic turnover of phosphate‐starvation inducible tomato purple acid phosphatase isozymes

Transcriptional regulation of plant phosphate transporters

Contact Info

Product

Resources

About