Faba bean (Vicia faba L.) varieties reveal substantial and contrasting organic phosphorus use efficiencies (PoUE) under symbiotic conditions

Abstract

BackgroundThe excessive use of inorganic P (Pi) in soils is alarming as it is causing numerous environmental problems and may lead to the depletion of rock phosphate reserves earlier than expected. Hence, to limit the over‐dependence on Pi, there is the need to investigate organic phosphorus (Po), which is the dominant P form of soil P pool, as an alternate P source for plant growth.AimThe present study seeks to investigate organic P use efficiency of eight varieties of faba bean grown symbiotically.MethodsThe plants were grown in pots (6 kg soil) under greenhouse condition with three P source, namely, phytic acid (organic P, Po), KH2PO4 (inorganic P, Pi), and no‐P. The P was applied at the rate of 1.79 g kg−1 soil.ResultsThe plants grown with Po and Pi produced similar amounts of root, shoot, and total dry matters. Despite producing statistically similar dry matters, P uptake by Pi‐fertilized plants was twofold higher than by Po‐fertilized plants. Meanwhile, Pi differed significantly from Po in terms of nodulation characteristics such as nodule dry biomass and individual nodule dry biomass. However, Po varied significantly from Pi in P utilization and acquisition efficiencies. Principal component analysis of Pi and Po revealed no significant variation and close association, confirming the nonsignificant differences between the two P treatments. Among the varieties tested, Tiffany tended to accumulate more dry matter, coupled with highest organic P utilization efficiency (0.48 g mg−1) as well as the highest organic P beneficiary factor (80%).ConclusionThese results provide a solid basis for further comparisons at physiological, biochemical, and molecular levels between Tiffany (Po‐efficient) and Fuego (Po‐inefficient) varieties, offering deep insights into and making it easier to understand the mechanisms that allow soil Po to be utilized under symbiotic conditions.

Mineral and Carbon Metabolic Adjustments in Nodules of Symbiotically Grown Faba Bean (Vicia faba L.) Varieties in Response to Organic Phosphorus Supplementation

“…However, P supplementation did not impact NDB or SPAD (Figures 1-3). Previous evidence has suggested that plants supplied with Po can amass more or equivalent biomass to Pi [14,16,21,22]. In this present study, Po treatment obtained the highest SDB (3%), PH, and growth rate (5 and 8%) in Tiffany and Hiverna, respectively, compared with +Pi.…”

“…Our group, however, was prompted by this development to research and gain insight into the effects of Po on SNF and nodulation in soil and hydroponics systems. Previously in our group, we have demonstrated that different faba bean varieties can acquire and utilize various sources of Po efficiently in soil [21,22]. These studies showed that faba bean plants supplemented with different Po sources produce equal biomass and have nodulation and SNF capacity similar to Pi.…”

“…3.1. Phytic Acid Supply Improves Growth and Partitions Higher Biomass, Similar to Inorganic P Prior to this work was an initial soil experiment aimed at assessing the effects of Po supply on the growth and efficient utilization of Po by diverse varieties of faba bean [22]. By changing the growth medium (from soil to hydroponics), we have confirmed and concluded that faba bean plants are competent users of phytic acid and accumulate more total biomass, which is better or equivalent to Pi-supplemented faba bean plants.…”

“…This paper thus presents an attestation that faba bean varieties can utilize Po, with Po supply imposing a staunch footprint on the growth and development of plants when exclusively depending on N derived from symbiotic nitrogen fixation, not only in soils [22], but also in hydroponic systems. The results showed significant differences in traits such as SDB, RDB, PH, and SD between treatments (Figures 1-3).…”

“…Thus, in the present study, we investigate how Po substrates (i.e., inositol phosphates) coordinately facilitate the mobilization, nutrient uptake, and anion and carbon metabolism in nodules of faba bean varieties that differ in organic phosphorus use efficiency (PoUE), as previously described [22], and assess the effect of Po on the symbiotic capacity and nitrogen fixation of Vicia faba plants when exclusively relying on N derived from nodule symbiosis. The present study hypothesized that higher P contents induced by phytic acid supplementation might play a significant role in the carbon metabolism by improving and providing the minerals and carbon required for the functioning of nodules.…”