Mild phosphorus stress in barley and a related low‐phosphorus‐adapted barleygrass: Phosphorus fractions and phosphate absorption in relation to growth

Abstract

Barleygrass (Hordeum leporinum) from Australian low‐P (phosphorus) soils and commercial barley (H. vulgare) with high fertilizer requirements were grown in solution culture at 3 levels of P supply. The high‐P‐adapted barley produced more biomass at all levels of P supply and was more responsive to added P in terms of rate of tillering, rate of leaf production, final leaf size, and therefore total shoot weight compared to barleygrass. In both species root: shoot ratio decreased in response to improved tissue P status, even at P levels where total biomass did not respond to P supply. Removal of endosperm reserves of barley reduced total biomass to a greater extent than it altered phosphate absorption rate, thus increasing tissue P status and making plants less responsive to added P. Similarly, barleygrass had a slower growth rate but a comparable P absorption rate to that of barley. Thus barleygrass also accumulated tissue P and was unresponsive to added P. All phosphorus chemical fractions increased in response to improved tissue P status, but to differing extents (inorganic‐P > nucleic acid‐P > lipid‐P > ester‐P), suggesting that all P fractions (particularly inorganic P) serve, in part, a storage function. Both barleygrass and barley without endosperm had higher concentrations of all P fractions (particularly inorganic P) than did unaltered barley, but this was due entirely to their higher P status (due to slow growth) rather than to any major difference in P metabolism between species. We conclude that slow growth is more important than interspecific differences in P metabolism, P absorption, or efficiency of P utilization in explaining the success of barleygrass and other low‐P‐adapted species on infertile soils.

Arsenate (As) uptake by and distribution in two cultivars of winter wheat (Triticum aestivum L.)

“…In the present hydroponic study, irrespective of external As concentrations, there were no significant differences in root biomass between the two cultivars ( Fig. 1), but both cultivars allocated relatively more biomass and more absorbed P into roots (higher root/shoot ratios) under low P conditions (32 lM) than under higher P conditions (161 lM; Table 1), which is a standard plant response to P deficiency (Chapin and Bieleshi, 1982). Lovrin 10 always had relatively more biomass allocated to roots than Jing 411, which is in agreement with the findings by Zou et al (2002).…”

“…Compared to higher P supply (161 lM), lower P supply (32 lM) resulted in more biomass allocated to roots (higher root/shoot ratios, Table 1), which is a standard plant response to P deficiency (Chapin and Bieleshi, 1982). This pattern also coincided with more absorbed As allocated into roots under 32 lM P supply than under 161 lM P supply (Fig.…”

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

“…In a classic study of barley growing on limiting P supply, about 26% was in free P, 17% was in phospholipids, 26% was in P-containing metabolites, including sugar Ps and nucleotide Ps, and 30% was in nucleic acids (Chapin and Bieleski, 1982). The vast majority of nucleic acids are in ribosomes, which are especially abundant in growing tissues (Detchon and Possingham, 1972;Dean and Leech, 1982;Baerenfaller et al, 2012), where they may represent an even greater proportion of the total P. Suc is known to increase gene expression for nucleotide synthesis and coordinately induce genes for ribosomal proteins and ribosome assembly, especially those for cytosolic ribosomes (Contento et al, 2004;Price et al, 2004;Bläsing et al, 2005;Zrenner et al, 2006;Kojima et al, 2007;Osuna et al, 2007;Usadel et al, 2008;Pal et al, 2013).…”

Identification and Characterization of the Arabidopsis PHO1 Gene Involved in Phosphate Loading to the Xylem

“…The determination of Pi in leaves was performed according to Chapin and Bieleski (1982) with some modifications. Surface-sterilized seed were grown for 10 days on nutrient medium plates before being transferred to soil.…”

“…Transgenic plants were selected by growing surface-sterilized plants on Murashige and Skoog (1962) medium containing 50 g/mL kanamycin. Transgenic plants were grown subsequently in soil under constant illumination.The determination of Pi in leaves was performed according to Chapin and Bieleski (1982) with some modifications. Surface-sterilized seed were grown for 10 days on nutrient medium plates before being transferred to soil.…”