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Peroxidase activity in scutella of maize in association with anatomical changes during germination and grain storage.

Corona-Carrillo JI, Flores-Ponce M, Chávez-Nájera G, Díaz-Pontones DM - Springerplus (2014)

Bottom Line: Due to its composition, the FL prevents free diffusion and separates the embryo from the endosperm during germination.During storage at high relative humidity levels, which leads to fast or slow deterioration depending on the temperature, the activity of phenol peroxidase in the scutellum was associated with a loss of vigor and reduced germination capacity when compared with low temperature and low relative humidity conditions.Such deterioration is associated with alterations in autofluorescent emissions from endogenous compounds in the scutellum, indicating changes in the microenvironment or in the differential proportions of epidermal and FL components.

View Article: PubMed Central - PubMed

Affiliation: Department of Health Sciences, Division of Biological and Health Sciences, Laboratory for Tissue Biochemistry, Universidad Autónoma Metropolitana-Iztapalapa, Mexico City, Mexico ; Posgrado en Biología Experimental, Division of Biological and Health Sciences, Universidad Autónoma Metropolitana-Iztapalapa, Mexico City, Mexico.

ABSTRACT
The embryo of the maize grain (Zea mays L.) is separated from the starchy endosperm by a fibrous structure, which is called the fibrous layer (FL). Using histochemical staining, it was determined that the FL is composed of collapsed cellular layers that contain phenols, neutral lipids, and 1,3-ő≤-glucan. Due to its composition, the FL prevents free diffusion and separates the embryo from the endosperm during germination. Twenty-four hours after imbibition, the scutellum epidermis initiated a series of asynchronous spatial modifications, including cell growth, the perforation of cell walls, increased peroxidase activity in the apoplastic space, and elevated levels of superoxide, phenols, and other components that interact with the fibrous layer, enabling its transformation in addition to the free flow between compartments. During storage at high relative humidity levels, which leads to fast or slow deterioration depending on the temperature, the activity of phenol peroxidase in the scutellum was associated with a loss of vigor and reduced germination capacity when compared with low temperature and low relative humidity conditions. Such deterioration is associated with alterations in autofluorescent emissions from endogenous compounds in the scutellum, indicating changes in the microenvironment or in the differential proportions of epidermal and FL components.

No MeSH data available.


Related in: MedlinePlus

Scutellum extruded compounds capable of reduction of FeCl3-K3Fe(CN)6. Amount of reduced phenols that interact with FeCl3-K3Fe(CN)6. Results are shown as means‚ÄȬĪ‚ÄČSD of n‚ÄČ=‚ÄČ3. ANOVA and Tukey-Kramer Multiple-Comparison Tests were performed with p‚ÄČ<‚ÄČ0.05.
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Fig6: Scutellum extruded compounds capable of reduction of FeCl3-K3Fe(CN)6. Amount of reduced phenols that interact with FeCl3-K3Fe(CN)6. Results are shown as means‚ÄȬĪ‚ÄČSD of n‚ÄČ=‚ÄČ3. ANOVA and Tukey-Kramer Multiple-Comparison Tests were performed with p‚ÄČ<‚ÄČ0.05.

Mentions: Because compounds with reducing capacities were extruded from the scutellum to the apoplast, other components were assayed in vitro to determine their interactions with XTT (Table¬†1). At concentrations within the mM range, the highest reduction capacity was observed with catechin, the lowest with gallic acid, and intermediate levels were detected with ascorbic acid. At concentrations in the őľM range, CuCl2 showed the same reduction power as gallic acid. The capacity for NADH to reduce XTT was similar to that of CuCl2 at equimolar conditions while that of NADPH was slightly lower. These results indicate that the compounds that are extruded from the scutellum (Figure¬†5, first column) may potentially include other types of reducing factors. It has been reported that the scutellum surface adjacent to the endosperm can reduce ferricyanide (Szcziparev 2006), which had been previously reported for the in situ localization of phenols (Price and Butler 1977). For this reason, the FeCl3-K3Fe(CN)6 reduction power was measured in the scutellum extrudates following 18, 24, and 36¬†h of imbibition, in which the amount of extruded phenols did not significantly change between measurements, although there was a slight increase after 24¬†h of imbibition of 17% or 47% when compared with the measurements that were obtained after 18 or 36¬†h of imbibition (Figure¬†6). These results indicate that reduced phenols in the apoplast can be found within a timeframe that is strictly regulated and coincides with the maintenance of basal values of XTT reduction (Figure¬†5, first column).Table 1


Peroxidase activity in scutella of maize in association with anatomical changes during germination and grain storage.

Corona-Carrillo JI, Flores-Ponce M, Chávez-Nájera G, Díaz-Pontones DM - Springerplus (2014)

Scutellum extruded compounds capable of reduction of FeCl3-K3Fe(CN)6. Amount of reduced phenols that interact with FeCl3-K3Fe(CN)6. Results are shown as means‚ÄȬĪ‚ÄČSD of n‚ÄČ=‚ÄČ3. ANOVA and Tukey-Kramer Multiple-Comparison Tests were performed with p‚ÄČ<‚ÄČ0.05.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4128954&req=5

Fig6: Scutellum extruded compounds capable of reduction of FeCl3-K3Fe(CN)6. Amount of reduced phenols that interact with FeCl3-K3Fe(CN)6. Results are shown as means‚ÄȬĪ‚ÄČSD of n‚ÄČ=‚ÄČ3. ANOVA and Tukey-Kramer Multiple-Comparison Tests were performed with p‚ÄČ<‚ÄČ0.05.
Mentions: Because compounds with reducing capacities were extruded from the scutellum to the apoplast, other components were assayed in vitro to determine their interactions with XTT (Table¬†1). At concentrations within the mM range, the highest reduction capacity was observed with catechin, the lowest with gallic acid, and intermediate levels were detected with ascorbic acid. At concentrations in the őľM range, CuCl2 showed the same reduction power as gallic acid. The capacity for NADH to reduce XTT was similar to that of CuCl2 at equimolar conditions while that of NADPH was slightly lower. These results indicate that the compounds that are extruded from the scutellum (Figure¬†5, first column) may potentially include other types of reducing factors. It has been reported that the scutellum surface adjacent to the endosperm can reduce ferricyanide (Szcziparev 2006), which had been previously reported for the in situ localization of phenols (Price and Butler 1977). For this reason, the FeCl3-K3Fe(CN)6 reduction power was measured in the scutellum extrudates following 18, 24, and 36¬†h of imbibition, in which the amount of extruded phenols did not significantly change between measurements, although there was a slight increase after 24¬†h of imbibition of 17% or 47% when compared with the measurements that were obtained after 18 or 36¬†h of imbibition (Figure¬†6). These results indicate that reduced phenols in the apoplast can be found within a timeframe that is strictly regulated and coincides with the maintenance of basal values of XTT reduction (Figure¬†5, first column).Table 1

Bottom Line: Due to its composition, the FL prevents free diffusion and separates the embryo from the endosperm during germination.During storage at high relative humidity levels, which leads to fast or slow deterioration depending on the temperature, the activity of phenol peroxidase in the scutellum was associated with a loss of vigor and reduced germination capacity when compared with low temperature and low relative humidity conditions.Such deterioration is associated with alterations in autofluorescent emissions from endogenous compounds in the scutellum, indicating changes in the microenvironment or in the differential proportions of epidermal and FL components.

View Article: PubMed Central - PubMed

Affiliation: Department of Health Sciences, Division of Biological and Health Sciences, Laboratory for Tissue Biochemistry, Universidad Autónoma Metropolitana-Iztapalapa, Mexico City, Mexico ; Posgrado en Biología Experimental, Division of Biological and Health Sciences, Universidad Autónoma Metropolitana-Iztapalapa, Mexico City, Mexico.

ABSTRACT
The embryo of the maize grain (Zea mays L.) is separated from the starchy endosperm by a fibrous structure, which is called the fibrous layer (FL). Using histochemical staining, it was determined that the FL is composed of collapsed cellular layers that contain phenols, neutral lipids, and 1,3-ő≤-glucan. Due to its composition, the FL prevents free diffusion and separates the embryo from the endosperm during germination. Twenty-four hours after imbibition, the scutellum epidermis initiated a series of asynchronous spatial modifications, including cell growth, the perforation of cell walls, increased peroxidase activity in the apoplastic space, and elevated levels of superoxide, phenols, and other components that interact with the fibrous layer, enabling its transformation in addition to the free flow between compartments. During storage at high relative humidity levels, which leads to fast or slow deterioration depending on the temperature, the activity of phenol peroxidase in the scutellum was associated with a loss of vigor and reduced germination capacity when compared with low temperature and low relative humidity conditions. Such deterioration is associated with alterations in autofluorescent emissions from endogenous compounds in the scutellum, indicating changes in the microenvironment or in the differential proportions of epidermal and FL components.

No MeSH data available.


Related in: MedlinePlus