Genetic and physiological traits for internal phosphorus utilization efficiency in rice

Abstract

Phosphorus (P) is an essential macronutrient for plant growth and development. Phosphorus is usually applied as fertilizer obtained from rock phosphate which is a non-renewable resource. Therefore, developing rice varieties that can use P more efficiently is crucial. Here, we investigated genotypic differences in traits related to internal Phosphorus Utilization Efficiency (PUE) in five rice genotypes grown under P-deficient conditions. P-efficient rice genotypes showed higher total biomass. This was partly due to higher root biomass, which in turn relied on preferential allocation of P to roots in these genotypes. Changes in P content and tissue P concentrations were analyzed in individual leaves at different time points. Genotypes belonging to the high-PUE group responded more quickly to P starvation in terms of reducing leaf P concentrations and they were able to reduce these concentrations to a lower level compared to the low-PUE group. Changes in P concentrations were reflected in gene expression levels for genes involved in lipid remodeling. Sulfolipid (OsSQD2) and galactolipid (OsMGD and OsDGD) synthesis-related genes were generally induced due to P starvation with most pronounced up-regulation in OsDGD1 and OsMGD3, but patterns differed between genotypes. A significantly higher expression of OsDGD5 and OsMGD1 & 2 was detected in the youngest fully expanded leaf of the high-PUE genotype group, whereas expression levels were reversed in older leaves. This pattern would confirm that P efficient genotypes react faster to P starvation in terms of freeing P for redistribution to growing tissues and replacing phospholipids with galactolipids in younger leaves may contribute to this aspect.

Understanding the Adaptive Mechanisms of Plants to Enhance Phosphorus Use Efficiency on Podzolic Soils in Boreal Agroecosystems

“…Internal phosphorus utilization efficiency (IPUE) is defined as the biomass produced per unit of P that accumulated in tissues. Higher IPUE has been attributed to optimum P translocation to harvestable plant parts by P re-translocation through phosphatase activities, P transporters ( Table 2 ), and related mechanisms to transfer P from shoots to grains in different crop species (Parentoni and Souza Júnior, 2008 ; Rose and Wissuwa, 2012 ; Li et al, 2017 ; Adem et al, 2020 ). Plant P status largely determines IPUE through allocation and remobilization processes from different plant compartments.…”

“…For instance, compared to Arabidopsis , six Proteaceae species from southwestern Australia in severely P-impoverished soil showed a higher percentage of galactolipids and sulfolipids during the vegetative stage (Lambers et al, 2012b ). Expression of galactolipids and sulfolipid biosynthesis-related genes in younger leaves is generally up-regulated during P starvation in high-PUE rice genotypes (Adem et al, 2020 ). Diacylglycerol is considered an important intermediate in phospholipid degradation, which is the precursor for galactolipid biosynthesis.…”

Comparative transcriptome analysis reveals a rapid response to phosphorus deficiency in a phosphorus-efficient rice genotype

“…Rice breeders cross modern high yielding varieties with P-efficient rice varieties, which are generally lower-yielding; to effectively transfer P-efficient traits to the modern varieties 20 . The P-efficient rice breeding programs generally aim for two traits, namely (1) P acquisition efficiency (PAE) that accounts for greater P uptake from soil and (2i) P utilisation efficiency (PUE) that produces greater yield and biomass per unit P 21 .…”

Genetic variation in morphological traits in cotton and their roles in increasing phosphorus-use-efficiency in response to low phosphorus availability

“…In this study, the decreasing PUE under CK conditions may result from the accumulation of external phosphorus beyond what is required for growth, negatively impacting a plant’s P economy ( Supplementary Table S2 ). This indicates that while plants can absorb more P than they need, external phosphorus cannot constantly encourage growth ( Julia et al., 2018 ; Adem et al., 2020 ). In this study, no changes in NUE were seen in cotton genotypes when plants were grown under both nutrition circumstances ( Figure 3F , Supplementary Table S2 ).…”