Phosphate Acquisition

Abstract

Phosphate (Pi) is considered to be one of the least available plant nutrients in the soil. High-affinity Pi transporters are generally accepted as entry points for Pi in the roots. The physiological, genetic, molecular and biochemical analysis of phosphate starvation response mechanisms highlight the ability of plants to adapt and thrive under phosphate limiting conditions. These responses help them enhance the availability of Pi, increase its uptake and improve the use-efficiency of Pi within a plant. Enhanced ability to acquire Pi appears to be regulated at the level of transcription of high-affinity phosphate transporters. These transporters are encoded by a family of small number of genes having characteristic tissue and organ associated expression patterns. Many of them are strongly induced during phosphate deficiency thus providing plants with enhanced ability to acquire and transfer phosphate. In addition, plants also activate biochemical mechanisms that could lead to increased acquisition of phosphate from both inorganic and organic phosphorus sources in the soil. Furthermore, altered root morphology and mycorrhizal symbiosis further enhance the ability of plants to acquire Pi. Interestingly most of these responses appear to be coordinated by changes in cellular phosphate levels. It is becoming apparent that phosphate acquisition and utilization are associated with activation or inactivation of a host of genes in plants. In this article we describe molecular, biochemical and physiological factors associated with phosphate acquisition by plants.

Phosphatase activity in temperate pasture soils: Potential regulation of labile organic phosphorus turnover by phosphodiesterase activity

“…In studies of individual organisms, the expression of phosphatase activity increases in response to the degree of P limitation (Raghothama, 1999;TorrianiGorini, 1994). In the soils studied here, no link was found between phosphatase activity and labile inorganic P, although activities were strongly correlated with labile organic P. Relationships were different for the two phosphatases studied and were determined mainly by soil pH.…”

Nutrition, dry matter accumulation and partitioning and phosphorus use efficiency of potato grown at different phosphorus levels in nutrient solution

“…Plants growing at low P levels develop adaptive mechanisms, such as changes in morphology and architecture of the root system (Raghothama & Karthikeyan, 2005), as well as in physiological characteristics of roots (José et al, 2003). Root systems with larger root surface, length and density usually ensure a high P uptake efficiency when P availability is low (Hu et al, 2010).…”

Mechanisms of enhanced inorganic phosphorus accumulation by periphyton in paddy fields as affected by calcium and ferrous ions

“…e l s e v i e r . c o m / l o c a t e / s c i t o t e n v (Fageria et al, 2011;Raghothama, 1999). Farmers commonly apply a large base dose of P fertilizer before planting rice (Ayaga et al, 2006;Lan et al, 2012).…”