Biotechnological mechanism for improving plant remobilization of phosphorus during leaf senescence

Abstract

SummaryPhosphorus enrichment of aquatic ecosystems through diffuse source pollution is an ongoing issue worldwide. A potential solution lies in the use of fast‐growing, multipurpose feedstocks, such as trees, to limit the flow of phosphorus into riparian areas through luxury consumption. However, the perennial nature of trees and their use of leaves as storage organs for excess phosphorus may reduce the effectiveness of contaminant removal during periods of leaf abscission. In an attempt to improve phosphorus remobilization during autumnal senescence, transgenic hybrid poplar P39 (Populus alba × Populus grandidentata) and Arabidopsis thaliana harbouring a constitutively expressed low‐affinity potato phosphate transporter (35S::StPht1‐1) were generated using Agrobacterium‐mediated transformation. For both species, the highest expressing 35S::StPht1‐1 lines were grown alongside wild‐type plants and subjected to increasing phosphate applications. StPht1‐1 expression in A. thaliana led to a reduction in biomass when grown under high‐phosphate conditions and had no effect on phosphate remobilization during senescence. In contrast, StPht1‐1 constitutive expression in P39 resulted in increased leaf phosphate content in the highest expressing transgenic line and minimal to no effect on P resorption efficiency. Surprisingly, sulphate resorption showed the greatest improvement in all three transgenic poplar lines, displaying a 31%–37% increase in resorption efficiency. These results highlight the complexity of nutrient resorption mechanisms in plants.

An insight into potential phosphate bioremediation and renewable energy from agricultural waste via integrated wastewater treatment systems in Indonesia

“…The existence of PolyP can be dynamic in cells. Two terms related to the availability of PolyP inside cells are 'luxury uptake' and 'overplus response' (Powell et al 2009, Da Ros andMansfield 2020). Luxury uptake occurs when there is an abundance of P in the environment.…”

Variability and limits of nitrogen and phosphorus resorption during foliar senescence

“…Phloem loading of mobile metabolites is the final step of resorption after nutrients are mobilized. Mobilized nutrients should ideally be completely exported, but simple metabolites, such as Pi and amino acids, may be an important fraction of [Nu] sen ( Chapin and Kedrowski, 1983 ; Da Ros and Mansfield, 2020 ), raising the possibility that NuR may be limited by low phloem loading ( Chapin and Moilanen, 1991) . This possibility led Yasumura et al.…”

“…(2006) to propose that [N] sen >25% accounted for by proteins was due to accumulation of free amino acids. Similarly, low PR and accumulation of Pi in senesced leaves under abundant P was suggested to indicate a limitation in the rate of Pi export by transporters at the vacuole ( Da Ros and Mansfield, 2020 ).…”

Enhancement of Zn tolerance and accumulation in plants mediated by the expression of Saccharomyces cerevisiae vacuolar transporter ZRC1

“…are fast growing trees, characterized by deep root system and large aerial biomass, which can be obtained within few growing seasons in the temperate zone (Yadav et al 2010 ; Bredemeier et al 2015 ). They are easily propagated, have the aptitude to be coppiced (Rockwood et al 2004 ), and have well-established industrial uses such as bioenergy, pulp and paper production, as well as ecological applications in the form of windbreaks and shelterbelts (da Ros and Mansfields 2020 ). Most importantly, as poplars are not a source of food, the risk of heavy metals entering the food chain is low.…”