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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-β-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

Chemical composition of fibrous layer. a, location of lipids detected by Oil Red O; b, location of lipids detected by Sudan IV; c, fluorescence of phenols enhanced with diphenylborinic acid; d, presence of β-glucan of the callose type identified by aniline blue. Abbreviations: ep, epidermal cells; fl, fibrous layer; pc, parenchyma cells; se, central starchy endosperm. Bar: a-d, 50 μm.
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Fig1: Chemical composition of fibrous layer. a, location of lipids detected by Oil Red O; b, location of lipids detected by Sudan IV; c, fluorescence of phenols enhanced with diphenylborinic acid; d, presence of β-glucan of the callose type identified by aniline blue. Abbreviations: ep, epidermal cells; fl, fibrous layer; pc, parenchyma cells; se, central starchy endosperm. Bar: a-d, 50 μm.

Mentions: The epidermis of the scutellum in a mature embryo is constituted of a monostratified layer of cuboidal cells (Figure 1a-d). Enveloping the scutellum is the FL, which is in intimate contact with the epidermal cells of the scutellum and generates the border of the SE as previously reported by Enríquez-Arredondo et al. (2005). The epidermal cells, the parenchyma of the scutellum, and the SE remnants show intense red staining with Oil Red O (Figure 1a) and Sudan IV (Figure 1b), indicating the presence of lipids, as expected due to their storage functions (Szcziparev 2006; Tan and Morrison 1979). Lipids are also visible in the FL region, although they are less prominent. The greatest level of fluorescence was detected in the FL due to the presence of phenolic compounds (Figure 1c), whereas the phenols were widely distributed on the walls of the parenchyma and the epidermal cells of the scutellum. Aniline blue, which detects β-glucanes of the callose type, showed bright blue fluorescence in the FL in contrast with the white fluorescence that was observed of the cells from the epidermis and parenchyma (Figure 1d).Figure 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)

Chemical composition of fibrous layer. a, location of lipids detected by Oil Red O; b, location of lipids detected by Sudan IV; c, fluorescence of phenols enhanced with diphenylborinic acid; d, presence of β-glucan of the callose type identified by aniline blue. Abbreviations: ep, epidermal cells; fl, fibrous layer; pc, parenchyma cells; se, central starchy endosperm. Bar: a-d, 50 μm.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Fig1: Chemical composition of fibrous layer. a, location of lipids detected by Oil Red O; b, location of lipids detected by Sudan IV; c, fluorescence of phenols enhanced with diphenylborinic acid; d, presence of β-glucan of the callose type identified by aniline blue. Abbreviations: ep, epidermal cells; fl, fibrous layer; pc, parenchyma cells; se, central starchy endosperm. Bar: a-d, 50 μm.
Mentions: The epidermis of the scutellum in a mature embryo is constituted of a monostratified layer of cuboidal cells (Figure 1a-d). Enveloping the scutellum is the FL, which is in intimate contact with the epidermal cells of the scutellum and generates the border of the SE as previously reported by Enríquez-Arredondo et al. (2005). The epidermal cells, the parenchyma of the scutellum, and the SE remnants show intense red staining with Oil Red O (Figure 1a) and Sudan IV (Figure 1b), indicating the presence of lipids, as expected due to their storage functions (Szcziparev 2006; Tan and Morrison 1979). Lipids are also visible in the FL region, although they are less prominent. The greatest level of fluorescence was detected in the FL due to the presence of phenolic compounds (Figure 1c), whereas the phenols were widely distributed on the walls of the parenchyma and the epidermal cells of the scutellum. Aniline blue, which detects β-glucanes of the callose type, showed bright blue fluorescence in the FL in contrast with the white fluorescence that was observed of the cells from the epidermis and parenchyma (Figure 1d).Figure 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-β-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