Figure S1. Cluster heat map of gene expression data. Table S1. Results of Real-time RT-PCR experi... more Figure S1. Cluster heat map of gene expression data. Table S1. Results of Real-time RT-PCR experiments performed for a set of transcripts resulted differentially expressed in the different comparison of microarray analysis. Table S2. Number of differentially expressed transcripts resulted by root transcriptional profile comparisons of Fe-deficient plants supplied for 1Â h with the three natural sources of Fe and Fe-sufficient plants. Figure S2. Shared transcripts modulated in Fe-deficient plants after 1Â h in response to supply with the three natural Fe sources relative to Fe-sufficient plants. Table S5. Sequence of forward and reverse primers used in Real-time RT-PCR experiments. (PDF 2631Â kb)
SPAD index values of leaf tissues were measured on 12, 15 and 19-day-old maize plants grown under... more SPAD index values of leaf tissues were measured on 12, 15 and 19-day-old maize plants grown under Fe-deficient- or Fe-sufficient-condition (−Fe and + Fe plants, respectively). Figure S2. External acidification of maize roots under Fe deficiency (B, D) and Fe sufficiency (A, C). Figure S3. Functional distribution among Gene Ontology (GO) categories of up- and down-regulated transcripts differentially modulated by Fe deficiency (−Fe vs + Fe transcriptomic comparison). Figure S4. Overview of up- (A) and down- (B) modulated transcripts in -Fe vs + Fe comparison using MapMan-bincode classification. Figure S5. Iron-(59Fe) accumulated in maize leaves (A) and roots (B). Figure S6. Phosphorous-(32P) accumulated in maize leaves (A) and roots (B). (PDF 6393 kb)
The low bioavailability of nutrients, especially nitrogen (N) and phosphorus (P), is one of the m... more The low bioavailability of nutrients, especially nitrogen (N) and phosphorus (P), is one of the most limiting factors for crop production. In this study, under N‐ and P‐free nutrient solution (−N−P), nodulating white lupin plants developed some nodules and analogous cluster root structures characterized by different morphological, physiological, and molecular responses than those observed upon single nutrient deficiency (strong acidification of external media, a better nutritional status than −N+P and +N−P plants). The multi‐elemental analysis highlighted that the concentrations of nutrients in white lupin plants were mainly affected by P availability. Gene‐expression analyses provided evidence of interconnections between N and P nutritional pathways that are active to promote N and P balance in plants. The root exudome was mainly characterized by N availability in nutrient solution, and, in particular, the absence of N and P in the nutrient solution triggered a high release of phen...
White lupin (Lupinus albus L.) has developed a highly efficient strategy to mobilize nutrients fr... more White lupin (Lupinus albus L.) has developed a highly efficient strategy to mobilize nutrients from soil, in particular when P is scarcely available. This strategy is based on the modification of the root architecture with the formation of cluster roots. From these structures, a huge quantity of root exudates (organic acids and flavonoids) are released. These exudates mobilize sparingly available nutrients in soils via complexation, ligand exchange and, in the case of flavonoids, reduction . These secondary metabolites can also influence the biological characteristics of the rhizosphere, affecting the presence and activity of the microorganisms. Hence acquiring a better comprehension of physiological, biochemical and molecular mechanisms that regulates roots exudation processes is fundamental for the improvement of the mineral nutrition of plants. It is well known that in P-deficient conditions, in the mix of flavonoids released by white lupin, genistein is the one mainly rappresented and it is exuded mainly from the early stages of the proteoid roots; nevertheless up to now there are no data on proteins involved in this processes even if in some plant species transmembrane flavonoid transport via MATE or ABC transporters has been already characterized. The aim of this work is the physiological, biochemical and molecular characterization of a protein putatively involved in the release of genistein from white lupin plants. Via cDNA-AFLP a gene sequence sharing a high similarity with known MATE proteins involved in flavonoid transport had been isolated. This gene was called LaMATE2 and analyses of its expression shown that it is upregulated in P-deficient white lupin roots. To investigate the role of LaMATE2 in genistein exudation, a RNA interference approach was used with the aim to knock down the expression of this gene and to analyses its effect on the exudate release activity of the transformed roots. qPCR results confirmed that the LaMATE2 expression was reduced and HPLC-analyses of the composition of root exudates revealed that these roots released less genistein. To biochemically characterize the activity of LaMATE2, the full-length cDNA of the gene was clone and expressed in Saccharomyces cerevisiae. The membrane vesicles isolated from transformed yeast were then used to perform transport assay of 3H-genistein. Microsomes isolated from yeast cells that express LaMATE2, compared to the control, accumulated a higher amount of the flavonoid in short time (30 s) and long time of the reaction (10 min). These data demonstrate that LaMATE2 protein is involved in the transport of genistein. Finally, it has been demostrated to be localized on the plasma membrane of Arabidopsis transformed protoplast
The simultaneous presence of different N‐forms in the rhizosphere leads to beneficial effects on ... more The simultaneous presence of different N‐forms in the rhizosphere leads to beneficial effects on nitrogen (N) nutrition in plants. Although widely used as fertilizers, the occurrence of cross connection between urea and ammonium nutrition has been scarcely studied in plants. Maize fed with a mixture of urea and ammonium displayed a better N‐uptake efficiency than ammonium‐ or urea‐fed plants (Buoso et al., Plant Physiol Biochem, 2021a; 162: 613–623). Through multiomic approaches, we provide the molecular characterization of maize response to urea and ammonium nutrition. Several transporters and enzymes involved in N‐nutrition were upregulated by all three N‐treatments (urea, ammonium, or urea and ammonium). Already after 1 day of treatment, the availability of different N‐forms induced specific transcriptomic and metabolomic responses. The combination of urea and ammonium induced a prompt assimilation of N, characterized by high levels of some amino acids in shoots. Moreover, ZmAMT1...
Figure S1. Cluster heat map of gene expression data. Table S1. Results of Real-time RT-PCR experi... more Figure S1. Cluster heat map of gene expression data. Table S1. Results of Real-time RT-PCR experiments performed for a set of transcripts resulted differentially expressed in the different comparison of microarray analysis. Table S2. Number of differentially expressed transcripts resulted by root transcriptional profile comparisons of Fe-deficient plants supplied for 1Â h with the three natural sources of Fe and Fe-sufficient plants. Figure S2. Shared transcripts modulated in Fe-deficient plants after 1Â h in response to supply with the three natural Fe sources relative to Fe-sufficient plants. Table S5. Sequence of forward and reverse primers used in Real-time RT-PCR experiments. (PDF 2631Â kb)
SPAD index values of leaf tissues were measured on 12, 15 and 19-day-old maize plants grown under... more SPAD index values of leaf tissues were measured on 12, 15 and 19-day-old maize plants grown under Fe-deficient- or Fe-sufficient-condition (−Fe and + Fe plants, respectively). Figure S2. External acidification of maize roots under Fe deficiency (B, D) and Fe sufficiency (A, C). Figure S3. Functional distribution among Gene Ontology (GO) categories of up- and down-regulated transcripts differentially modulated by Fe deficiency (−Fe vs + Fe transcriptomic comparison). Figure S4. Overview of up- (A) and down- (B) modulated transcripts in -Fe vs + Fe comparison using MapMan-bincode classification. Figure S5. Iron-(59Fe) accumulated in maize leaves (A) and roots (B). Figure S6. Phosphorous-(32P) accumulated in maize leaves (A) and roots (B). (PDF 6393 kb)
The low bioavailability of nutrients, especially nitrogen (N) and phosphorus (P), is one of the m... more The low bioavailability of nutrients, especially nitrogen (N) and phosphorus (P), is one of the most limiting factors for crop production. In this study, under N‐ and P‐free nutrient solution (−N−P), nodulating white lupin plants developed some nodules and analogous cluster root structures characterized by different morphological, physiological, and molecular responses than those observed upon single nutrient deficiency (strong acidification of external media, a better nutritional status than −N+P and +N−P plants). The multi‐elemental analysis highlighted that the concentrations of nutrients in white lupin plants were mainly affected by P availability. Gene‐expression analyses provided evidence of interconnections between N and P nutritional pathways that are active to promote N and P balance in plants. The root exudome was mainly characterized by N availability in nutrient solution, and, in particular, the absence of N and P in the nutrient solution triggered a high release of phen...
White lupin (Lupinus albus L.) has developed a highly efficient strategy to mobilize nutrients fr... more White lupin (Lupinus albus L.) has developed a highly efficient strategy to mobilize nutrients from soil, in particular when P is scarcely available. This strategy is based on the modification of the root architecture with the formation of cluster roots. From these structures, a huge quantity of root exudates (organic acids and flavonoids) are released. These exudates mobilize sparingly available nutrients in soils via complexation, ligand exchange and, in the case of flavonoids, reduction . These secondary metabolites can also influence the biological characteristics of the rhizosphere, affecting the presence and activity of the microorganisms. Hence acquiring a better comprehension of physiological, biochemical and molecular mechanisms that regulates roots exudation processes is fundamental for the improvement of the mineral nutrition of plants. It is well known that in P-deficient conditions, in the mix of flavonoids released by white lupin, genistein is the one mainly rappresented and it is exuded mainly from the early stages of the proteoid roots; nevertheless up to now there are no data on proteins involved in this processes even if in some plant species transmembrane flavonoid transport via MATE or ABC transporters has been already characterized. The aim of this work is the physiological, biochemical and molecular characterization of a protein putatively involved in the release of genistein from white lupin plants. Via cDNA-AFLP a gene sequence sharing a high similarity with known MATE proteins involved in flavonoid transport had been isolated. This gene was called LaMATE2 and analyses of its expression shown that it is upregulated in P-deficient white lupin roots. To investigate the role of LaMATE2 in genistein exudation, a RNA interference approach was used with the aim to knock down the expression of this gene and to analyses its effect on the exudate release activity of the transformed roots. qPCR results confirmed that the LaMATE2 expression was reduced and HPLC-analyses of the composition of root exudates revealed that these roots released less genistein. To biochemically characterize the activity of LaMATE2, the full-length cDNA of the gene was clone and expressed in Saccharomyces cerevisiae. The membrane vesicles isolated from transformed yeast were then used to perform transport assay of 3H-genistein. Microsomes isolated from yeast cells that express LaMATE2, compared to the control, accumulated a higher amount of the flavonoid in short time (30 s) and long time of the reaction (10 min). These data demonstrate that LaMATE2 protein is involved in the transport of genistein. Finally, it has been demostrated to be localized on the plasma membrane of Arabidopsis transformed protoplast
The simultaneous presence of different N‐forms in the rhizosphere leads to beneficial effects on ... more The simultaneous presence of different N‐forms in the rhizosphere leads to beneficial effects on nitrogen (N) nutrition in plants. Although widely used as fertilizers, the occurrence of cross connection between urea and ammonium nutrition has been scarcely studied in plants. Maize fed with a mixture of urea and ammonium displayed a better N‐uptake efficiency than ammonium‐ or urea‐fed plants (Buoso et al., Plant Physiol Biochem, 2021a; 162: 613–623). Through multiomic approaches, we provide the molecular characterization of maize response to urea and ammonium nutrition. Several transporters and enzymes involved in N‐nutrition were upregulated by all three N‐treatments (urea, ammonium, or urea and ammonium). Already after 1 day of treatment, the availability of different N‐forms induced specific transcriptomic and metabolomic responses. The combination of urea and ammonium induced a prompt assimilation of N, characterized by high levels of some amino acids in shoots. Moreover, ZmAMT1...
Uploads
Papers by Nicola Tomasi