Phosphate Uptake by Spirodela and Lemna during Early Phosphorus Deficiency

McPharlin, I. R.; Bieleski, R. L.

doi:10.1071/pp9870561

Cited by 11 publications

(22 citation statements)

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“…Plants assimilate phosphate (Pi) from the soil, which is largely determined by the capacity of plants to enhance Pi uptake during nutrient deficiency (McPharlin and Bieleski, 1987;Furihata et al, 1992). Over the past decade, it has been clearly found that the increase of Pi uptake in plants is correlated with an increased number of high-affinity Pi transporters assembled in the plasma membrane (Drew and Saker, 1984;Shimogawara and Usuda, 1995;Muchhal and Raghothama, 1999).The locations of transcripts and translated Pi transporters in plants are shown to be constitutive or organ and tissue specific.…”

Section: Tissue Expression Patternmentioning

confidence: 99%

Expression, transcriptional regulation and functional analysis of phosphate transporter genes in plants

Guo

Zhao

Sun

et al. 2010

Front. Agric. China

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Phosphorus is one of the essential mineral nutrients required by all living cells. Phosphate mobilization into the plant is a complex process in which the absorption and translocation of this major nutrient are determined largely by the phosphate (Pi) transporters. In this paper, the recent progress on the plant phosphate (Pi) transporter genes, such as the molecular characterizations, expression patterns in response to Pi status, other inorganic nutrients, and the other factors, expression regulations via arbuscular mycorrhizal (AM) symbiosis, mechanisms of transcriptional regulation, functional identification approaches, and the gene engineering perspectives on improvement of plant phosphorus nutrition, etc., have been reviewed. The purpose of this paper is to provide a theoretical basis for further elucidation of the molecular mechanism of Pi transportation mediated by Pi transporters and to promote the generation of elite crop germplasms with a significant improvement in phosphorus use efficiency in the future.

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Section: Tissue Expression Patternmentioning

confidence: 99%

Expression, transcriptional regulation and functional analysis of phosphate transporter genes in plants

Guo

Zhao

Sun

et al. 2010

Front. Agric. China

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Section: Measurement Of Pi Infixmentioning

confidence: 99%

“…and Lemna major L. plants were grown in sterile culture as described (Bieleski 1968a;McPharlin and Bieleski 1987). Rates of orthophosphate (Pi) influx (gross Pi influx) by + P and -P Spirodela and Lemna plants from 1, 10, 100 or l 0 O O p~ external Pi were measured as described by McPharlin and Bieleski (1987). Rates of gross Pi influx were also determined at 1000 p~ external Pi in + P plants at 5, 15 and 25°C and when one of four inhibitors of metabolism; CCCP (3 p~) , NaAs04.7H20 (400 p~) , KCN (1000 p~) or NaNs (1000 p~) was added to the external solution.…”

Section: Measurement Of Pi Infixmentioning

confidence: 99%

“…The composition of the nutrient solutions was the same as used previously (McPharlin and Bieleski 1987). It was assumed that a 10 day exposure to 3 2~i was sufficient time to ensure uniform labelling of all P in the plants as the doubling time for growth of both species was approximately 2 days (McPharlin and Bieleski 1987).…”

Section: Measurement Of Rates Of Pi Efluxmentioning

confidence: 99%

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PI Efflux and Influx by P-Adequate and P-Deficient Spirodela and Lemna

McPharlin¹,

Bieleski²

1989

Functional Plant Biol.

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Net Pi influx by P-adequate ( + P ) and P-deficient (-P) Spirodela and Lemna plants was determined by gross Pi influx and Pi efflux. Rates of Pi influx (gross) and Pi efflux were sensitive to both internal [PI and external [Pi]. The different responses of these two fluxes to external [Pi] resulted in their rates converging at low external [Pi], from Pi efflux being 9-10% of gross Pi influx at 1000 p~ Pi to being over 70% at low (1 p~) external Pi in + P plants. At very low external Pi (0.34 p~, 0.22 p~ Pi for + P Spirodela and Lemna, respectively), rates of gross Pi influx and Pi efflux were assumed to be either equal or zero (referred to as the equilibrium [Pilext), such that net Pi influx was zero. There was assumed to be insufficient Pi diffusing to the carrier site on the root surface at very low external [Pi] (i.e. equilibrium [P,],,,) for the phosphate pump to operate and Pi influx was zero. P deficiency resulted in a simultaneous reduction in rates of Pi efflux and an increase in gross Pi influx such that the equilibrium [Pilext was reduced 3-4 times (0.8, 0.07 p~ Pi for -P Spirodela and Lemna respectively) compared with + P plants. Some of the limitations of Pi diffusion to the carrier sites in P-adequate plants are overcome as internal [PI decreases during P deficiency. As a consequence the ability of Spirodela and Lemna to extract Pi from solution during P deficiency was considerably greater than for plants with adequate P status.Inhibitors of metabolism (low temperatures, arsenate, azide, cyanide and CCCP) reduced rates of gross Pi influx but increased rates of Pi efflux such that net Pi influx was reduced. These findings are discussed in relation to previous work on the kinetics of Pi influx in -P versus + P plants and the role of changes in membrane potentials in the enhancement of Pi influx and reduction of Pi efflux capacity in P-deficient Spirodela and Lemna.

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“…Recent Wndings from the chemical inhibition and transgenic studies provide evidence that the plasma membrane H + -ATPase is also involved in P uptake in soybean (Shen et al 2006). In vascular plants, at least two forms of PTs are known and they are classiWed based on the Pi absorption kinetics and aYnity to target Pi i.e., high-aYnity PTs, Km (Pi) = 3-7 M; low-aYnity PTs Km (Pi) = 50-330 M (Furihata et al 1992;McPharlin and Bieleski 1987;Ullrich-Eberius et al 1984). The high-and low-aYnity PTs belong to Pht1 and Pht2 families, respectively, (Bucher et al 2001).…”

Section: Introductionmentioning

confidence: 99%

Overexpression of a high-affinity phosphate transporter gene from tobacco (NtPT1) enhances phosphate uptake and accumulation in transgenic rice plants

Park

Baek²,

Reyes

et al. 2007

Plant Soil

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High-aYnity phosphate transporters (PTs) have been suggested as major components of mechanisms of inorganic phosphate (Pi) uptake in plant cells. In this study, we investigated the role of PT in improving Pi uptake by transgenic overexpression of a tobacco (Nicotiana tabacum L.) gene encoding a high-aYnity PT (NtPT1) in rice (Oryza sativa L.) plants. The NtPT1 transgene driven by the maize ubiquitin (Ubi) promoter was expressed constitutively in transgenic rice plants at very high levels both in low (32 M Pi) and high (320 M Pi) Pi conditions. The rate of Pi uptake increased by 24% and 37% in the transgenic rice plants at low and high Pi conditions, respectively. SigniWcant increases in phosphorus (P) accumulation (41% (w/w) and 55% (w/w)) were observed in the leaves of the transgenic plants under low and high Pi conditions, respectively. The P content in the shoots of the transgenic plants grown in low-P soil with Pi applied at 0-62 mg/Kg soil was increased by 15% (w/w) to 29% (w/w). The P content in seeds of the transgenic plants grown under Weld conditions was also increased by 16% (w/w) to 25% (w/w). The positive correlation between Pi uptake and accumulation and NtPT1 transgene expression indicates transcriptional control of PT activity and an important regulatory role of PT in Pi uptake. These results also conWrm that high-aYnity PTs are important targets for the improvement of Pi acquisition in rice.

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Phosphate Uptake by Spirodela and Lemna during Early Phosphorus Deficiency

Cited by 11 publications

References 0 publications

Expression, transcriptional regulation and functional analysis of phosphate transporter genes in plants

Expression, transcriptional regulation and functional analysis of phosphate transporter genes in plants

PI Efflux and Influx by P-Adequate and P-Deficient Spirodela and Lemna

Overexpression of a high-affinity phosphate transporter gene from tobacco (NtPT1) enhances phosphate uptake and accumulation in transgenic rice plants

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