Differences in foliar phosphorus fractions, rather than in cell-specific phosphorus allocation, underlie contrasting photosynthetic phosphorus use efficiency among chickpea genotypes

Abstract

Although significant intraspecific variation in photosynthetic phosphorus (P)-use efficiency (PPUE) has been shown in numerous species, we still know little about the biochemical basis for differences in PPUE among genotypes within a species. Here, we grew two high-PPUE and two low-PPUE chickpea (Cicer arietinum) genotypes with low P supply in a glasshouse to compare their photosynthesis-related traits, total foliar P concentration ([P]) and chemical P fractions (i.e. inorganic P (Pi), metabolite P, lipid P, nucleic acid P and residual P). Foliar cell-specific nutrient concentrations including P were characterized using elemental X-ray microanalysis. Genotypes with high PPUE showed lower total foliar [P] without slower photosynthetic rates. No consistent differences in cellular [P] between the epidermis and mesophyll cells occurred across the four genotypes. In contrast, high PPUE was associated with lower allocation to Pi and metabolite P, with PPUE being negatively correlated with the percentage of these two fractions. Furthermore, a lower allocation to Pi and metabolite P was correlated with a greater allocation to nucleic acid P, but not to lipid P. Collectively, our results suggest that a different allocation to foliar P fractions, rather than preferential P allocation to specific leaf tissues underlies the contrasting PPUE among chickpea genotypes.

Phosphorus Availability Affects the Photosynthesis and Antioxidant System of Contrasting Low-P-Tolerant Cotton Genotypes

“…An increasing amount of research shows that achieving relatively fast rates of photosynthesis with high PPUE requires a delicate balance in investment among foliar-P fractions [64]. For instance, some plants suffering from P deficiency can decrease their overall requirement for foliar P by reducing investment in non-metabolite-P fractions to different degrees, thus buffering the direct P restriction of photosynthesis [11]. Plant species, and even genotypes of certain species, differ in their ability to maintain their photosynthetic activity under P limitation.…”

“…Plant species, and even genotypes of certain species, differ in their ability to maintain their photosynthetic activity under P limitation. Significant interspecific and intraspecific variation exists for PPUE under low-P stress [11]. However, our understanding of the biochemical basis for differences in PPUE among and within species is still in its infancy.…”

“…Plant species, and even genotypes of certain species, differ in their ability to maintain their photosynthetic activity under P limitation. Significant interspecific and intraspecific variation exists for photosynthetic P-use efficiency under low P availability [11,12].…”

Low Nocturnal Temperature Alters Tomato Foliar and Root Phosphorus Fractions Allocation by Reducing Soil Phosphorus Availability

“…The soil P is vital source of plant P nutrition [5]. Foliar P content is more bound up with soil available P than to soil total P [6].…”