Phosphorus and iron deficiencies induce a metabolic reprogramming and affect the exudation traits of the woody plantFragaria×ananassa

Abstract

Strawberries are a very popular fruit among berries, for both their commercial and economic importance, but especially for their beneficial effects for human health. However, their bioactive compound content is strictly related to the nutritional status of the plant and might be affected if nutritional disorders (e.g. Fe or P shortage) occur. To overcome nutrient shortages, plants evolved different mechanisms, which often involve the release of root exudates. The biochemical and molecular mechanisms underlying root exudation and its regulation are as yet still poorly known, in particular in woody crop species. The aim of this work was therefore to characterize the pattern of root exudation of strawberry plants grown in either P or Fe deficiency, by investigating metabolomic changes of root tissues and the expression of genes putatively involved in exudate extrusion. Although P and Fe deficiencies differentially affected the total metabolism, some metabolites (e.g. raffinose and galactose) accumulated in roots similarly under both conditions. Moreover, P deficiency specifically affected the content of galactaric acid, malic acid, lysine, proline, and sorbitol-6-phosphate, whereas Fe deficiency specifically affected the content of sucrose, dehydroascorbic acid, galactonate, and ferulic acid. At the same time, the citrate content did not change in roots under both nutrient deficiencies with respect to the control. However, a strong release of citrate was observed, and it increased significantly with time, being +250% and +300% higher in Fe- and P-deficient plants, respectively, compared with the control. Moreover, concomitantly, a significant acidification of the growth medium was observed in both treatments. Gene expression analyses highlighted for the first time that at least two members of the multidrug and toxic compound extrusion (MATE) transporter family and one member of the plasma membrane H(+)-ATPase family are involved in the response to both P and Fe starvation in strawberry plants.

Proline Accumulation Is Regulated by Transcription Factors Associated with Phosphate Starvation

“…2). These results correlate with recent metabolomic data, revealing that Pro accumulation is one of the consequences of phosphorus deficiency in several plant species (Pant et al, 2015b;Valentinuzzi et al, 2015). Pro accumulation in phosphatestarved plants is driven by enhanced expression of P5CS1, encoding the key enzyme in the Pro biosynthetic pathway.…”

“…Comprehensive metabolic profiling of phosphate-starved Arabidopsis plants revealed massive changes in primary and secondary metabolites, such as organic acids, sugars, glucosinolates, flavonoids, and amino acids, including Pro (Morcuende et al, 2007;Pant et al, 2015b;Valentinuzzi et al, 2015).…”

Time-Resolved Investigation of Molecular Components Involved in the Induction of NO3– High Affinity Transport System in Maize Roots

“…(Arango et al, 2003), Vitis vinifera (Pii et al, 2014), and Fragaria vesca (Valentinuzzi et al, 2015). The amino acid sequences were obtained from public databases 1, 2 , 3 (The Arabidopsis Information Resource (TAIR), MSU) and the relative accession numbers were reported in Supplementary Table S1.…”

The interplay between sulfur and iron nutrition in tomato

“…In addition to the increased accumulation of organic acids, particularly citric acid, in roots facilitating Fe mobilization (Rellán-Álvarez et al, 2011;Valentinuzzi et al, 2015), metabolite profiles reported in Figure 8 and Table II showed that Fe deficiency induced an accumulation of Glc and Fru. A drop of pyruvic acid in plants exposed to sulfate deficiency indicates a slowdown of the glycolytic pathway, especially prevalent under combined Fe and S starvation, where additionally Glc-6-P levels were reduced (Fig.…”