Phosphate nutrition effects on growth, phosphate transporter transcript levels and physiology of alfalfa cells

Abstract

Phosphorus deficiency reduces forage yield and stand persistence of alfalfa (Medicago sativa L.). Our objectives were to isolate and characterize a high-affinity phosphate-transporter (P-transporter) from alfalfa roots (Medicago sativa L.); determine how phosphorus (P) nutrition impacts P-uptake, growth, and carbohydrate and protein metabolism of alfalfa cells; and learn how expression of the P-transporter is influenced by P nutrition. An 1087-base pair (bp) sequence was isolated using RT-PCR that possessed high nucleotide and amino acid sequence similarity to high-affinity P-transporters. Cultured cells were sampled at 3-day intervals for 9 days while growing in media containing P concentrations ranging from 0 to 10 mM. Media P concentrations declined rapidly in all P treatments by day 6. Low media P concentrations (0, 0.1 and 0.5 mM) reduced cell growth rates compared to higher media P levels (2.5, 5 and 10 mM). Suspension cell cultures supplied 0.5, 2.5, 5, and 10 mM P had lower starch concentrations by day 3 compared to cells cultured in media containing 0 and 0.1 mM P. Steady-state transcript levels for the high-affinity P-transporter were high in P-deprived cells, but declined within 1 day when cells were provided 10 mM P.Abbreviations: 2,4-D D -2,4-dichlorophenoxyacetic acid; MS -Murashige and Skoog; P -phosphorus; P-transporter -phosphate-transporter

Shear rate as scale-up criterion of the protein production with enhanced proteolytic activity by phosphate addition in the Jacaratia mexicana cell culture

“…The protein content was neither affected by the phosphate concentration nor by the vitamin type (data not shown). This behaviour was similar in an alfalfa cell culture, where the soluble protein concentration in media supplemented with phosphorus was not significantly different when the phosphorus concentration increased from 0.5 mmol L −1 to 5 mmol L −1 [17].…”

“…Under this hydrodynamic condition, the cells were smaller and thinner compared to cell culture in bubble column and airlift bioreactors (40 s −1 ). The phosphate was 1.25 mmol L −1 (the basal phosphate concentration reported in Murashige & Skoog (MS) [15]) in the experiments mentioned above; however, few reports have mentioned that increasing phosphate concentration could improve the protein concentration [16][17][18].…”

Phosphate Nutrition and Defoliation Effects on Growth and Root Physiology of Alfalfa

“…To verify the ability of this cDNA to detect transcript for the highaffinity P-transporter, we conducted Northern analyses using RNA from a separate P-nutrition experiment. As expected, transcript for the high-affinity P-transporter was high in suspension cells grown in P-depleted media, and declined rapidly as cells were transferred to media containing high P levels (Abu Qamar et al, 2005). While steady-state transcript levels for this high-affinity P-transporter can be enhanced under P limiting conditions, significant inconsistencies exist that will require additional research in order to understand the role of these putative transporters in P uptake by soil-grown alfalfa.…”

Pemetaan, Karakterisasi, dan Pengembangan Primer-primer Lokus Pup1 (P uptake 1) pada Padi untuk Peningkatan Toleransi terhadap Defisiensi Fosfor

“…Penelitian terkini menyebutkan toleransi terhadap defisiensi P berbanding lurus dengan aktivitas P transporter yang membawa P ke dalam sel tanaman, seperti yang dibuktikan pada sel tanaman alfafa (Abu Qamar et al, 2005). Fosfat transporter ini jenisnya bisa berbeda-beda untuk setiap jenis tanaman.…”