Opportunities for improving phosphorus‐use efficiency in crop plants

Abstract

Contents Summary306I.The need to use phosphorus efficiently307II.P‐use efficiency and P dynamics in a growing crop307III.P pools in plants307IV.Phosphorus pools and growth rates310V.Are crops different from other plants in their P concentration?310VI.Phosphorus use and photosynthesis311VII.Crop development and canopy P distribution312VIII.Internal redistribution of P in a growing vegetative plant313IX.Allocation of P to reproductive structures314X.Constraints to P remobilisation315XI.Do physiological or phylogenetic trade‐offs constrain traits that could improve PUE?316XII.Identifying genetic loci associated with PUE316XIII.Conclusions317Acknowledgements317References317 Summary Limitation of grain crop productivity by phosphorus (P) is widespread and will probably increase in the future. Enhanced P efficiency can be achieved by improved uptake of phosphate from soil (P‐acquisition efficiency) and by improved productivity per unit P taken up (P‐use efficiency). This review focuses on improved P‐use efficiency, which can be achieved by plants that have overall lower P concentrations, and by optimal distribution and redistribution of P in the plant allowing maximum growth and biomass allocation to harvestable plant parts. Significant decreases in plant P pools may be possible, for example, through reductions of superfluous ribosomal RNA and replacement of phospholipids by sulfolipids and galactolipids. Improvements in P distribution within the plant may be possible by increased remobilization from tissues that no longer need it (e.g. senescing leaves) and reduced partitioning of P to developing grains. Such changes would prolong and enhance the productive use of P in photosynthesis and have nutritional and environmental benefits. Research considering physiological, metabolic, molecular biological, genetic and phylogenetic aspects of P‐use efficiency is urgently needed to allow significant progress to be made in our understanding of this complex trait.

Expression of Sucrose Transporter cDNAs Specifically in Companion Cells Enhances Phloem Loading and Long-Distance Transport of Sucrose but Leads to an Inhibition of Growth and the Perception of a Phosphate Limitation

“…Increasing photosynthesis to enhance plant productivity is a prominent goal of plant biology (Ainsworth and Bush, 2011;Evans and von Caemmerer, 2011), as is increasing P use efficiency to minimize the need for this nonrenewable resource in agricultural production and to reduce the deleterious impacts of P used in fertilizers (Veneklaas et al, 2012). The implications of the study presented here are that efforts to enhance photosynthesis and growth by increasing Suc export may be compromised by the plant's perception that it requires more P, unless the links between carbohydrate and P homeostasis are better understood and uncoupled.…”

“…In addition, it was recently shown that ubiquitous SUT OE can induce a P deficiency response (Lei et al, 2011), potentially by disrupting normal Suc distribution patterns. It is understandable that normal and efficient Suc transport is required for an effective response to P limitation, because P limitation induces processes that have a high demand for photoassimilate, such as growth of lateral roots and root hairs, changes in gene expression, remodeling of metabolism, secretion of organic acids, and energization of membranes (Misson et al, 2005;Morcuende et al, 2007;Plaxton and Tran, 2011;Veneklaas et al, 2012). However, what is significant and different about the result presented here compared to previous studies is that enhanced Suc transport along the normal distribution path triggers a P-limited phenotype.…”

“…In addition to being important for metabolic activities, sugars provide the majority of biomass for new growth and storage, are important signaling molecules for plant growth and development (Rolland et al, 2006), and interact with other essential nutrients. For example, more carbon from source organs is required for a response to a phosphorous limitation because P deficiencies induce many changes that have high demand for photoassimilate, including enhanced growth of lateral roots and root hairs, changes in gene expression, remodeling of metabolism, secretion of organic acids, and energization of membranes (Misson et al, 2005;Morcuende et al, 2007;White, 2008, 2011;Plaxton and Tran, 2011;Veneklaas et al, 2012). Conversely, utilization of sugars and storage carbohydrates requires P for metabolism, which occurs mostly by ATPdependent formation of phosphoesters.…”

Rhizosphere Effect of Kharif Crops on Phosphatases and Dehydrogenase Activities in a Typic Haplustert

“…It maintains biochemical, metabolic functions in plants; maintains soil fertility and soil health [3]. But lower phosphorus use efficiency limits crop yield and economic return [4]. Phosphorus fertilizers are totally imported in India and indigenous rock phosphate having low P concentration, increasing crop production cost.…”

A phospholipid uptake system in the model plant Arabidopsis thaliana

“…Second, the desired portion of phospholipids may not be the energy-rich acyl chain but rather the phosphate group. Phosphate is a major growth-limiting factor for plants and internalization of phospholipids could contribute to phosphate uptake 31 . In this context, ALA10 could also function as a sensor of phospholipids in the soil environment that initiates signalling events leading to secretion of phosphatases.…”