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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

Morphological aspects of plants (shoot and rhizophores) of Chrysolaena obovata submitted to daily watering—control, water suppression (WS) and re-watering (RW). Time zero (A), day 7 (B), day 10 (C), day 12 (D), day 17 (E), day 22 (F).
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Figure 2: Morphological aspects of plants (shoot and rhizophores) of Chrysolaena obovata submitted to daily watering—control, water suppression (WS) and re-watering (RW). Time zero (A), day 7 (B), day 10 (C), day 12 (D), day 17 (E), day 22 (F).

Mentions: Soil moisture and water potential (Ψwsoil) were unchanged in the control throughout the experiment. Water suppression (WS) caused a decrease in moisture, reaching 5% after 10 days, while re-watering (RW) led to soil moisture recovery in 2 days (Figures 1A,B). Similarly, water content in leaves and rhizophores were unchanged in control plants, diminished in WS and recovered in RW plants. In the latter, water content in aerial organs was only partially recovered (Figures 1C,D), while wilted aspect was maintained (Figure 2). WS treatment led to a decrease in water potential of leaves (Ψwleaf) and rhizophores (Ψwrhiz) (Figures 1E,F), followed by a recovery after re-watering at day 10. The soil water deficit imposed by WS treatment led to a severe and permanent wilting of the aerial organs from day 12 (Ψwleaf = −2.0 MPa), while re-watering at day 10 allowed the rhizophores (Ψwrhiz = −2.1 MPa) to recover the water potential within 2 days to levels similar to control plants (Ψwrhiz = −1.0 MPa). The rhizophores presented a turgid aspect in RW plants at days 12, 17, and 22 (Figures 2D,E,F), which paralleled the recovery of water content and water potential of these organs after re-watering. As shown in Figure 2, the aerial organs of RW plants maintained the wilted aspect as observed in WS plants, contrasting with the rhizophores of RW plants, that recovered the turgid aspect after re-watering at day 10 (Figures 2D,E,F). Figure 2 clearly shows that rhizophores of RW plants presented the same morphological aspect of those from DW plants (control).


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)

Morphological aspects of plants (shoot and rhizophores) of Chrysolaena obovata submitted to daily watering—control, water suppression (WS) and re-watering (RW). Time zero (A), day 7 (B), day 10 (C), day 12 (D), day 17 (E), day 22 (F).
© Copyright Policy
Related In: Results  -  Collection

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

Figure 2: Morphological aspects of plants (shoot and rhizophores) of Chrysolaena obovata submitted to daily watering—control, water suppression (WS) and re-watering (RW). Time zero (A), day 7 (B), day 10 (C), day 12 (D), day 17 (E), day 22 (F).
Mentions: Soil moisture and water potential (Ψwsoil) were unchanged in the control throughout the experiment. Water suppression (WS) caused a decrease in moisture, reaching 5% after 10 days, while re-watering (RW) led to soil moisture recovery in 2 days (Figures 1A,B). Similarly, water content in leaves and rhizophores were unchanged in control plants, diminished in WS and recovered in RW plants. In the latter, water content in aerial organs was only partially recovered (Figures 1C,D), while wilted aspect was maintained (Figure 2). WS treatment led to a decrease in water potential of leaves (Ψwleaf) and rhizophores (Ψwrhiz) (Figures 1E,F), followed by a recovery after re-watering at day 10. The soil water deficit imposed by WS treatment led to a severe and permanent wilting of the aerial organs from day 12 (Ψwleaf = −2.0 MPa), while re-watering at day 10 allowed the rhizophores (Ψwrhiz = −2.1 MPa) to recover the water potential within 2 days to levels similar to control plants (Ψwrhiz = −1.0 MPa). The rhizophores presented a turgid aspect in RW plants at days 12, 17, and 22 (Figures 2D,E,F), which paralleled the recovery of water content and water potential of these organs after re-watering. As shown in Figure 2, the aerial organs of RW plants maintained the wilted aspect as observed in WS plants, contrasting with the rhizophores of RW plants, that recovered the turgid aspect after re-watering at day 10 (Figures 2D,E,F). Figure 2 clearly shows that rhizophores of RW plants presented the same morphological aspect of those from DW plants (control).

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