The protein kinase Pstol1 from traditional rice confers tolerance of phosphorus deficiency

Abstract

As an essential macroelement for all living cells, phosphorus is indispensable in agricultural production systems. Natural phosphorus reserves are limited, and it is therefore important to develop phosphorus-efficient crops. A major quantitative trait locus for phosphorus-deficiency tolerance, Pup1, was identified in the traditional aus-type rice variety Kasalath about a decade ago. However, its functional mechanism remained elusive until the locus was sequenced, showing the presence of a Pup1-specific protein kinase gene, which we have named phosphorus-starvation tolerance 1 (PSTOL1). This gene is absent from the rice reference genome and other phosphorus-starvation-intolerant modern varieties. Here we show that overexpression of PSTOL1 in such varieties significantly enhances grain yield in phosphorus-deficient soil. Further analyses show that PSTOL1 acts as an enhancer of early root growth, thereby enabling plants to acquire more phosphorus and other nutrients. The absence of PSTOL1 and other genes-for example, the submergence-tolerance gene SUB1A-from modern rice varieties underlines the importance of conserving and exploring traditional germplasm. Introgression of this quantitative trait locus into locally adapted rice varieties in Asia and Africa is expected to considerably enhance productivity under low phosphorus conditions.

Duplicate and Conquer: Multiple Homologs ofPHOSPHORUS-STARVATION TOLERANCE1Enhance Phosphorus Acquisition and Sorghum Performance on Low-Phosphorus Soils

“…Furthermore, lines overexpressing OsPupK46-2 showed an approximately 30% grain yield increase in comparison with the null lines, suggesting that PSTOL1 has potential for molecular breeding applications to improve crop performance under low-P conditions. Consistent with the proposed physiological mechanism underlying OsPSTOL1, the superior performance of the transgenic lines was related to enhanced root dry weight, root length, and root surface area (Gamuyao et al, 2012).…”

“…Following high-resolution mapping of Pup1, comparative sequence analyses of homologous bacterial artificial chromosomes showed that a Kasalath genomic fragment contained several genes not present in cv Nipponbare, highlighting an approximately 90-kb deletion in the cv Nipponbare reference genome that encompassed the Pup1 locus (Heuer et al, 2009). Within this insertion/deletion, OsPupK46-2, a gene encoding a Ser/Thr kinase of the Receptor-like Protein Kinase LRK10L-2 subfamily, was found to enhance grain yield and P uptake in rice lines overexpressing this gene, indicating that this protein kinase underlies the Pup1 locus (Gamuyao et al, 2012). OsPupK46-2, which is now designated PHOSPHORUS-STARVATION TOLERANCE1 (OsPSTOL1), was found to be up-regulated in the root tissues of tolerant near-isogenic lines under P-deficient conditions and was shown to increase P uptake by a physiological mechanism based on the enhancement of early root growth and development.…”

Differential effects of nitrogen forms on cell wall phosphorus remobilization in rice (Oryza sativa) are mediated by nitric oxide, pectin content and the expression of the phosphate transporter OsPT2

“…For example, due to the specific PHOSPHORUS STARVATION TOLERANCE1 gene, the root system of Kas exhibits greater uptake of P in P-limited soils and is therefore more vigorous than that of Nip (Gamuyao et al, 2012). However, when grown in P-deficient solutions, Nip plants display increased P reutilization compared to Kas plants.…”

Physiological and molecular alterations in plants exposed to high [CO2] under phosphorus stress

“…Similarly, some glycolytic pathway related genes were induced in roots of L. albus under P starvation (Uhde-Stone et al, 2003a, b). In-depth study on molecular mechanisms defining the phosphate signalling pathway showed that Pup1-specific protein kinase gene, PSTOL1 is involved in regulating root growth and architecture during early stages (Gamuyao et al, 2012). Allele-specific markers for this gene have been reported recently (Pariasca-Tanaka et al, 2014).The systemic response to P starvation is carried through a complex signalling network which involves plant hormones (Nacry et al, 2005;Pérez-Torres et al, 2008;Li et al, 2012), sugars (Karthikeyan et al, 2007) and nitric oxide (Wang et al, 2010), and collectively result in the altered carbohydrate distribution between roots and shoots.…”