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Structural and metabolic changes in rhizophores of the Cerrado species Chrysolaena obovata (Less.) Dematt. as influenced by drought and re-watering.

Garcia PM, Hayashi AH, Silva EA, Figueiredo-Ribeiro Rde C, Carvalho MA - Front Plant Sci (2015)

Bottom Line: Inulin sphero-crystals accumulated in parenchymatic cells of the cortex, vascular tissues and pith were reduced under drought and accompanied anatomical changes, starting from day 10.At 22 days of drought, the cortical and vascular tissues were collapsed, and inulin sphero-crystals and inulin content were reduced.The localization of inulin sphero-crystals in vascular tissues of C. obovata, as well as the decrease of total inulin and the increase in oligo:polysaccharide ratio in water stressed plants is consistent with the role of fructans in protecting plants against drought.

View Article: PubMed Central - PubMed

Affiliation: Núcleo de Pesquisa em Fisiologia e Bioquímica, Instituto de Botânica São Paulo, Brazil ; Programa de Pós-Graduação em Biodiversidade Vegetal e Meio Ambiente, Instituto de Botânica São Paulo, Brazil.

ABSTRACT
The high fructan contents in underground organs of Cerrado species, high water solubility, and fast metabolism of these compounds highlight their role as carbon storage and as an adaptive feature in plants under drought. In this study, we showed that anatomical structure, in association with soluble compounds and metabolism of inulin-type fructans were modified in rhizophores of Crysolaena obovata submitted to water suppression and recovery after re-watering. Plants were subjected to daily watering (control), suppression of watering for 22 days (water suppression) and suppression of watering followed by re-watering after 10 days (re-watered). Plants were collected at time 0 and after 3, 7, 10, 12, 17, and 22 days of treatment. In addition to changes in fructan metabolism, high proline content was detected in drought stressed plants, contributing to osmoregulation and recovery after water status reestablishment. Under water suppression, total inulin was reduced from approx. 60 to 40%, mainly due to exohydrolase activity. Concurrently, the activity of fructosyltransferases promoted the production of short chain inulin, which could contribute to the increase in osmotic potential. After re-watering, most parameters analyzed were similar to those of control plants, indicating the resumption of regular metabolism, after water absorption. Inulin sphero-crystals accumulated in parenchymatic cells of the cortex, vascular tissues and pith were reduced under drought and accompanied anatomical changes, starting from day 10. At 22 days of drought, the cortical and vascular tissues were collapsed, and inulin sphero-crystals and inulin content were reduced. The localization of inulin sphero-crystals in vascular tissues of C. obovata, as well as the decrease of total inulin and the increase in oligo:polysaccharide ratio in water stressed plants is consistent with the role of fructans in protecting plants against drought.

No MeSH data available.


Related in: MedlinePlus

Contents of fructo-oligosaccharides (A), fructo- polysaccharides (B), oligo:polysaccharide ratio (C), and reducing sugars (D) in rhizophores of Chrysolaena obovata submitted to daily watering—control (■), water suppression (○) and re-watering (●). Arrows in indicate re-watering at day 10. Values are means ± SE (n = 3). Means followed by *indicate significant differences in relation to control (P = 0.05 by LSD procedure).
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Figure 7: Contents of fructo-oligosaccharides (A), fructo- polysaccharides (B), oligo:polysaccharide ratio (C), and reducing sugars (D) in rhizophores of Chrysolaena obovata submitted to daily watering—control (■), water suppression (○) and re-watering (●). Arrows in indicate re-watering at day 10. Values are means ± SE (n = 3). Means followed by *indicate significant differences in relation to control (P = 0.05 by LSD procedure).

Mentions: The amount of total fructans decreased slowly throughout the experiment, from 571.43 mg g−1DM at day 0 to 349.58 in control plants, 420.68 in WS plants and 450.97 mg g−1DM in RW, at day 22. At the end of the experimental period, fructo-oligosaccharide contents in WS and RW plants were significantly higher than in control (Figure 7A), while the polysaccharide contents were lower (Figure 7B). The ratio oligo:polysaccharides increased in WS plants from day 7, while RW plants showed a transitory increase at day 17, that was reverted at the end of the experimental period (Figure 7C). Water suppression caused a significant increase in reducing sugars from day 10 on and decreased rapidly after re-watering (Figure 7D). These results are consistent with the high proportion of hexoses, mainly fructose, as detected by anion exchange chromatography (HPAEC/PAD) (Supplementary Figure 1).


Structural and metabolic changes in rhizophores of the Cerrado species Chrysolaena obovata (Less.) Dematt. as influenced by drought and re-watering.

Garcia PM, Hayashi AH, Silva EA, Figueiredo-Ribeiro Rde C, Carvalho MA - Front Plant Sci (2015)

Contents of fructo-oligosaccharides (A), fructo- polysaccharides (B), oligo:polysaccharide ratio (C), and reducing sugars (D) in rhizophores of Chrysolaena obovata submitted to daily watering—control (■), water suppression (○) and re-watering (●). Arrows in indicate re-watering at day 10. Values are means ± SE (n = 3). Means followed by *indicate significant differences in relation to control (P = 0.05 by LSD procedure).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4585265&req=5

Figure 7: Contents of fructo-oligosaccharides (A), fructo- polysaccharides (B), oligo:polysaccharide ratio (C), and reducing sugars (D) in rhizophores of Chrysolaena obovata submitted to daily watering—control (■), water suppression (○) and re-watering (●). Arrows in indicate re-watering at day 10. Values are means ± SE (n = 3). Means followed by *indicate significant differences in relation to control (P = 0.05 by LSD procedure).
Mentions: The amount of total fructans decreased slowly throughout the experiment, from 571.43 mg g−1DM at day 0 to 349.58 in control plants, 420.68 in WS plants and 450.97 mg g−1DM in RW, at day 22. At the end of the experimental period, fructo-oligosaccharide contents in WS and RW plants were significantly higher than in control (Figure 7A), while the polysaccharide contents were lower (Figure 7B). The ratio oligo:polysaccharides increased in WS plants from day 7, while RW plants showed a transitory increase at day 17, that was reverted at the end of the experimental period (Figure 7C). Water suppression caused a significant increase in reducing sugars from day 10 on and decreased rapidly after re-watering (Figure 7D). These results are consistent with the high proportion of hexoses, mainly fructose, as detected by anion exchange chromatography (HPAEC/PAD) (Supplementary Figure 1).

Bottom Line: Inulin sphero-crystals accumulated in parenchymatic cells of the cortex, vascular tissues and pith were reduced under drought and accompanied anatomical changes, starting from day 10.At 22 days of drought, the cortical and vascular tissues were collapsed, and inulin sphero-crystals and inulin content were reduced.The localization of inulin sphero-crystals in vascular tissues of C. obovata, as well as the decrease of total inulin and the increase in oligo:polysaccharide ratio in water stressed plants is consistent with the role of fructans in protecting plants against drought.

View Article: PubMed Central - PubMed

Affiliation: Núcleo de Pesquisa em Fisiologia e Bioquímica, Instituto de Botânica São Paulo, Brazil ; Programa de Pós-Graduação em Biodiversidade Vegetal e Meio Ambiente, Instituto de Botânica São Paulo, Brazil.

ABSTRACT
The high fructan contents in underground organs of Cerrado species, high water solubility, and fast metabolism of these compounds highlight their role as carbon storage and as an adaptive feature in plants under drought. In this study, we showed that anatomical structure, in association with soluble compounds and metabolism of inulin-type fructans were modified in rhizophores of Crysolaena obovata submitted to water suppression and recovery after re-watering. Plants were subjected to daily watering (control), suppression of watering for 22 days (water suppression) and suppression of watering followed by re-watering after 10 days (re-watered). Plants were collected at time 0 and after 3, 7, 10, 12, 17, and 22 days of treatment. In addition to changes in fructan metabolism, high proline content was detected in drought stressed plants, contributing to osmoregulation and recovery after water status reestablishment. Under water suppression, total inulin was reduced from approx. 60 to 40%, mainly due to exohydrolase activity. Concurrently, the activity of fructosyltransferases promoted the production of short chain inulin, which could contribute to the increase in osmotic potential. After re-watering, most parameters analyzed were similar to those of control plants, indicating the resumption of regular metabolism, after water absorption. Inulin sphero-crystals accumulated in parenchymatic cells of the cortex, vascular tissues and pith were reduced under drought and accompanied anatomical changes, starting from day 10. At 22 days of drought, the cortical and vascular tissues were collapsed, and inulin sphero-crystals and inulin content were reduced. The localization of inulin sphero-crystals in vascular tissues of C. obovata, as well as the decrease of total inulin and the increase in oligo:polysaccharide ratio in water stressed plants is consistent with the role of fructans in protecting plants against drought.

No MeSH data available.


Related in: MedlinePlus