Nutrição Rhodophyta Ipê

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Maria do Carmo Mendes Gusmão
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1 Nutrição

2 Figure 2. Transcriptional profiles of genes differentially expressed in shoot of Arabidopsis plants subjected to N, P or K starvation. The number of genes responding to N, P or K deficiencies against a background of low an high shoot carbohydrate concentrations. Genes responding to high shoot carbohydrate concentrations were defined as genes differentially expresse in shoots of the pho3 mutant, which has constitutively high shoot carbohydrate concentrations, compared with wild-type plants [56]. Genes from segments highlighted in red and blue were classified in terms of their Gene Ontology (GO) categories. Metabolismo de C/fotossíntese vs nutrição mineral vs água (gráfico)... Figure 1. The effect of mineral supply on the morphology of Arabidopsis thaliana. (a) Individual fresh biomass (histograms) of plants grown in short days for 6 weeks in hydroponic systems containing a complete nutrient solution, then for 12 days in the same solution or one lacking the mineral element indicated. Biomass partitioning (pie charts) between root (R) and shoot aumenta (S) (mean ofa sixbiomassa values) is shown. das Salt substitutions raízes. from the complete nutrient solution [43] were follows: N deficiency, 0.2 mm CaNO3, 0.8 mm CaCl2; P deficiency, 0.25 mm KCl; K deficiency, 0.88 mm Na2SO4, 0.25 NaH2PO4; Mg deficiency, 1.00 mm Na2SO4. (b) Colour photographs of the plants in (a). (c) Iodine staining of the plants in (a). To visualize the differences in the distribution of starch (dark blue) following a dark period, iodine staining of whole plants was performed as a qualitative approach. Scale bar = 10 cm. N e P: acúmulo de carboidratos nas folhas, K e Mg: Por que não acontece o mesmo...?

viáveis presente em moléculas essenciais Elementos não

3 uais são os nutrientes? nde achá-los? bundância relativa? Elementos essenciais Ciclo completo gerando sementes viáveis presente em moléculas essenciais Elementos não minerais (C, O e H) > 96% do peso seco. -C ~45% -O ~45% -H ~6%

4 Efeitos e respostas à deficiência nutricional Alterações morfológicas: FISIOLÓGICAS Como estudar? Deficiência/excesso: hidroponia Inibidores de transporte Mutantes (de transportadores ou enzimas da assimilação) e complementaçao heteróloga

5 Deficiência e excesso Variação da concentração de um nutriente nos tecidos concentração crítica zona adequada faixa de deficiência faixa de toxicidade

6 Deficiência: Como resolver? Brassica napus (oil production) with or without S suplementation. Its seeds are rich in sulfur-containig compounds.

7 No solo... Disponibilidade dos íons no solo depende do ph e a concentração. Alto ph/baixo ph

8 omo entram os utrientes? H 2 O:Fluxo de massa + Difusão=osmose Concentração do xilema vs células? Transporte ativo aptações que auxiliam a sorção: Micorrizas (Pi): ectotróficas e vesículo-arbusculres. Nódulos de Rhizobium em Pea fixação biológia de N (nódulos ou endofíticas)

9 Transporte de nutrientes Estamos falando desde o ponto de vista do ion!!!! Por isso os livros falam de de difusão e potencial electroquímico (ou de soluto) exclusivamente... Difusão facilitada e/ou fluxo de massa

10 Transporte ativo (bombas) de nutrientes Cotransporte Simporte e Antiporte Não há degradação de AT Força motriz de prótons.

11 Quem gera o gradiente de H+? Transporte ativo (bombas) de H+: ATPases

12 P type V type

13 Transporte de S Metionina e cisteina: composição e estrutura proteica. Sulfato entra por um simporte para ser assimilado nos plastídios: cisteína e glutatione. APS: 5-adenilsulfato

14 Transporte de S

15 Transporte de S: o ciclo do enxofre.

16 Transporte de K + : livre pela planta Absorção - Simporte Transporte xilema: captação floema: translocação Dois transportadores alta afinidade (I) [ K + ] baixa afinidade (II) [ K + ou Na 2+ ]

17 Transporte de K + : vários canais com expressão diferencial

18 Transporte de Pi (Fosfatases) Associação com micorrizas. Acidificação do solo para solubilizar Pi inorgánico. Liberação de fosfohidroxylases para liberação de Pi de compostos organicos.

Transporte de Fe Gramíneas Mono não gramíneas e dicot

Redução do Fe 3+ a Fe 2+ pela redutase férrica.

19 Transporte de Fe Gramíneas Mono não gramíneas e dicot Fitosideróforo (PS) a partir da metionina Saída do PS. Associação do PS com o Fe 3+. Entrada do complexo e liberação do Fe 3 no interior. Redução do Fe 3+ a Fe 2+ pela redutase férrica. Entrada por simporte na célula. Indução da ATP ase para acidificar a rizosfera aumentando a solubilidade Ferritina: proteína que auxilia no transporte xilemático

20 Figure 2. Transcriptional profiles of genes differentially expressed in shoot of Arabidopsis plants subjected to N, P or K starvation. The number of genes responding to N, P or K deficiencies against a background of low an high shoot carbohydrate concentrations. Genes responding to high shoot carbohydrate concentrations were defined as genes differentially expresse in shoots of the pho3 mutant, which has constitutively high shoot carbohydrate concentrations, compared with wild-type plants [56]. Genes from segments highlighted in red and blue were classified in terms of their Gene Ontology (GO) categories. Metabolismo de C/fotossíntese vs nutrição mineral vs água... Figure 1. The effect of mineral supply on the morphology of Arabidopsis thaliana. (a) Individual fresh biomass (histograms) of plants grown in short days for 6 weeks in hydroponic systems containing a complete nutrient solution, then for 12 days in the same solution or one lacking the mineral element indicated. Biomass partitioning (pie charts) between root (R) and shoot (S) (mean of six values) is shown. Salt substitutions from the complete nutrient solution [43] were as follows: N deficiency, 0.2 mm CaNO3, 0.8 mm CaCl2; partição P deficiency, de 0.25 C mm (fonte-dreno). KCl; K deficiency, 0.88 mm Na2SO4, 0.25 NaH2PO4; Mg deficiency, 1.00 mm Na2SO4. (b) Colour photographs of the plants in (a). (c) Iodine staining of the plants in (a). To visualize the differences in the distribution of starch (dark blue) following a dark period, iodine staining of whole plants was performed as a qualitative approach. Scale bar = 10 cm. N e P: acúmulo de carboidratos nas folhas e altos níveis de C alocados nas raízes (aumenta a biomassa das raízes). Alteram fotossíntese e K e Mg: imposibilidade de transportar sacarose

N and P starvation: Sugar acumulation (starch),though, photosynthesis represion(negative feedback) By contrast upon N and P deficiencies, carbon partitioning favours root growth at the expense of

21 N and P starvation: Sugar acumulation (starch),though, photosynthesis represion(negative feedback) By contrast upon N and P deficiencies, carbon partitioning favours root growth at the expense of nutrient shortage by allocating biomass specific organs. Abbreviations: MC, mesophyll cell; VP, vascular parenchym BSC, bundle sheath cells; CC, compani cell; SE, sieve element; HC, heterotroph cell. (a) The root is devoted to mineral nutrient acquisition 5, 6, 7, 8, 9 and 10 and is the first organ to sense and signa mineral starvation 18, 71, 79 and 80. Crosstalk between root and shoot is established through xylem and phloem vascular tissues. (b) N, P, K and Mg deficiencies induce sugar accumulation MC, affecting photosynthesis and sugar metabolism 7, 11, 13, 16, 20, 28,30, 34, 43, 52, 65, 68, 70 and 75. (c) From the point of synthesis in MC to HC, sucrose loaded into the SE CC complex either through plasmodesmata by the symplas route or by the apoplastic route, depending on the mode of phloem loading. The apoplastic pathway require sucrose export from MC or BSC and reentry into the SE CC complex, mediate by sucrose H+ symporters, energized b plasma membrane H+-ATPase and facilitated by K+ channels. Mg deficienc can affect sucrose phloem loading (probably though H+-ATPase activity) and 43 and K deficiency can affect K phloem loading [78], limiting sucrose export to sink organs. By contrast upon N and P deficiencies, carbon partitioning favours root growth at th expense of the shoot. (d,e) Phloem unloading in sink cells can occur symplastically or through efflux carriers. is postulated that the flux of sugars delivered to sink organs is crucial for responses to mineral deficiencies. Suga regulate nutrient-responsive genes in sinks [66] and modify root morphology in

22 Nutrição...fim

23 Figure 3. Gene Ontology (GO) categories significantly (P < 0.005) over-represented in differentially regulated genes in shoots of N-, P- or K-deficient plants. Identification of significantly over-represented GO categories was performed using the GO Ontology Browser function in GeneSpring GX 7.3 (Aglient Technologies, Santa Clara, CA, USA). Genes significantly (P < 0.05) differentially regulated by N deficiency were abstracted from Ref. [20]. Genes significantly (P < 0.05) differentially regulated by K deficiency were abstracted from Ref. [76]. A list of genes significantly (P < 0.05) differentially regulated by P deficiency was abstracted from Refs 11, 17 and 23 and data on the pho1 mutant (NASC, Nottingham University, UK), which has constitutively low shoot P concentrations. Genes differentially expressed in shoots of the pho3 mutant compared with shoots of wild-type plants were abstracted from Ref. [56]. Text and shapes in red correspond to common significantly differentially regulated genes from N-deficient and P-deficient plants under low shoot carbohydrate conditions; text and shapes in blue correspond to common significantly differentially regulated genes from N- deficient and P-deficient plants under high shoot carbohydrate conditions; and text and shapes in purple correspond to overlaps between differentially regulated genes from N-deficient and P-deficient plants under low shoot carbohydrate conditions (red) and differentially regulated genes from N- deficient and P-deficient plants under high shoot carbohydrate conditions (blue).

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Nutrição e Nitrogênio Rhodophyta Ipê Figure 2. Transcriptional profiles of genes differentially expressed in shoots of Arabidopsis plants subjected to N, P or K starvation. The number of genes responding