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Moyano L, Correa MD, Favre LC, Rodríguez FS, Maldonado S, López-Fernández MP. Activation of Nucleases, PCD, and Mobilization of Reserves in the Araucaria angustifolia Megagametophyte During Germination. FRONTIERS IN PLANT SCIENCE 2018; 9:1275. [PMID: 30214454 PMCID: PMC6125354 DOI: 10.3389/fpls.2018.01275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Accepted: 08/14/2018] [Indexed: 06/08/2023]
Abstract
The megagametophyte of mature seeds of Araucaria angustifolia consists of cells with thin walls, one or more nuclei, a central vacuole storing proteins, and a cytoplasm rich in amyloplasts, mitochondria and lipid bodies. In this study, we describe the process of mobilization of reserves and analyzed the dismantling of the tissue during germination, using a range of well-established markers of programmed cell death (PCD), including: morphological changes in nuclei and amyloplasts, DNA degradation, and changes in nuclease profiles. TUNEL reaction and DNA electrophoresis demonstrate that DNA fragmentation in nuclei occurs at early stages of germination, which correlates with induction of specific nucleases. The results of the present study add knowledge on the dismantling of the megagametophyte of genus Araucaria, a storage tissue that stores starch as the main reserve substance, as well as on the PCD pathway, by revealing new insights into the role of nucleases and the expression patterns of putative nuclease genes during germination.
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Affiliation(s)
- Laura Moyano
- Departamento de Biodiversidad y Biología Experimental, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
- Consejo Nacional de Investigaciones Científicas Técnicas, Instituto de Biodiversidad y Biología Experimental y Aplicada, Buenos Aires, Argentina
| | - María D. Correa
- Departamento de Biodiversidad y Biología Experimental, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Leonardo C. Favre
- Departamentos de Industrias y Departamento de Química Orgánica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires, Argentina
| | - Florencia S. Rodríguez
- Departamento de Biodiversidad y Biología Experimental, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Sara Maldonado
- Departamento de Biodiversidad y Biología Experimental, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
- Consejo Nacional de Investigaciones Científicas Técnicas, Instituto de Biodiversidad y Biología Experimental y Aplicada, Buenos Aires, Argentina
| | - María P. López-Fernández
- Departamento de Biodiversidad y Biología Experimental, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
- Consejo Nacional de Investigaciones Científicas Técnicas, Instituto de Biodiversidad y Biología Experimental y Aplicada, Buenos Aires, Argentina
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Diedhiou C, Gaudet D, Liang Y, Sun J, Lu ZX, Eudes F, Laroche A. Carbohydrate profiling in seeds and seedlings of transgenic triticale modified in the expression of sucrose:sucrose-1-fructosyltransferase (1-SST) and sucrose:fructan-6-fructosyltransferase (6-SFT). J Biosci Bioeng 2012; 114:371-8. [DOI: 10.1016/j.jbiosc.2012.05.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2011] [Revised: 05/08/2012] [Accepted: 05/09/2012] [Indexed: 10/28/2022]
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Huberman M, Zehavi U, Stein WD, Etxeberria E, Goren R. In vitro sugar uptake by grapefruit (Citrus paradisi) juice-sac cells. FUNCTIONAL PLANT BIOLOGY : FPB 2005; 32:357-366. [PMID: 32689137 DOI: 10.1071/fp04125] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2004] [Accepted: 03/10/2005] [Indexed: 06/11/2023]
Abstract
To further our understanding of the mechanisms of sugar uptake and accumulation into grapefruit (Citrus paradisi Macf. cv. Marsh seedless), the patterns of uptake and utilisation of sucrose, glucose and fructose by Citrus juice cells was investigated. Analyses were conducted on sliced juice sacs that were incubated in radioactive [14C]-sugar solutions with unlabelled sugars, in the presence or absence of metabolic inhibitors. Both hexoses demonstrated an initial uptake peak in December and a second uptake peak in February-March. From March through April the rates of sucrose uptake increased to levels comparable to those of glucose and fructose. Sucrose and its moieties fructose and glucose entered the juice cells of Citrus juice fruit by an insaturable, and mostly by an independent, process. However, NaN3 and carbonylcyanide m-chlorophenylhydrazone (CCCP) produced slight inhibition of these processes. Cells took up hexoses at a greater rate than sucrose, with accumulation reaching a plateau by 4-8 h, and then continuing unabated, in the case of glucose, for 42 h. Uptake of all three sugars increased linearly in the range of sugar concentrations tested, which extended from 0.01 to 320 mm, denoting an insaturable system for sugar uptake. 14CO2 evolution was relatively low in all the experiments, the lowest evolution being recorded when the uptake of [14C]-sucrose was studied, while the highest 14CO2 evolution was recorded when the uptake of [14C]-glucose was studied. The data demonstrate a preferential utilisation of glucose over fructose and sucrose. In all the experiments, the two metabolic inhibitors significantly inhibited the decarboxylation of the three sugars.
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Affiliation(s)
- Moshe Huberman
- Robert H Smith Institute of Plant Sciences and Genetics in Agriculture, The Kennedy-Leigh Centre for Horticultural Research, The Hebrew University of Jerusalem, POB 12, Rehovot 76100, Israel
| | - Uri Zehavi
- Institute of Biochemistry, Food Science and Nutrition, The Hebrew University of Jerusalem, POB 12, Rehovot 76100, Israel
| | - Wilfred D Stein
- Biological Chemistry Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, POB 1255 Jerusalem 91904, Israel
| | - Ed Etxeberria
- Citrus Research and Education Center, University of Florida, 700 Experiment Station Road, Lake Alfred, FL 33850, USA
| | - Raphael Goren
- Robert H Smith Institute of Plant Sciences and Genetics in Agriculture, The Kennedy-Leigh Centre for Horticultural Research, The Hebrew University of Jerusalem, POB 12, Rehovot 76100, Israel
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Waghorn JJ, del Pozo T, Acevedo EA, Cardemil LA. The role of two isoenzymes of alpha-amylase of Araucaria araucana (Araucariaceae) on the digestion of starch granules during germination. JOURNAL OF EXPERIMENTAL BOTANY 2003; 54:901-911. [PMID: 12598561 DOI: 10.1093/jxb/erg093] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Starch is the principal reserve of Araucaria araucana seeds, and it is hydrolysed during germination mainly by alpha-amylase. There are several alpha-amylase isoenzymes whose patterns change in the embryo and in the megagametophyte from the one observed in quiescent seeds (T(0)) to a different one observed 90 h after imbibition (T(90)). The objective of this research was to study the roles of two purified alpha-amylase isoenzymes by in vitro digestion of starch granules extracted from the tissues at two times of imbibition: one is abundant in quiescent seeds and the other is abundant after 90 h of imbibition. The isoenzymes digested the starch granules of their own stage of germination better, since the isoenzyme T(0) digested starch granules mainly from quiescent seeds, while the isoenzyme T(90) digested starch mainly at 90 h of imbibition. The sizes of the starch granule and the tissue from which these granules originated make a difference to digestion by the isoenzymes. Embryonic isoenzyme T(0) digested large embryonic starch granules better than small and medium-sized granules, and better than those isolated from megagametophytes. Similarly isoenzyme T(90) digested small embryonic starch granules better than medium-sized and large granules, and better than those isolated from megagametophytes. However, a mixture of partially purified megagametophytic isoenzymes T(0) and T(90) digested the megagametophytic granules better than those isolated from embryos. Studies of in vitro sequential digestion of starch granules with these isoenzymes corroborated their specificity. The isoenzyme T(90) digested starch granules previously digested by the isoenzyme T(0). This suggests that in vivo these two isoenzymes may act sequentially in starch granule digestion.
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Affiliation(s)
- Juana J Waghorn
- Facultad de Ciencias, Universidad de Chile, Departamento de Biología, Casilla 653, Santiago, Chile
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Salas E, Cardemil L. The Multiple Forms of alpha-Amylase Enzyme of the Araucaria Species of South America: A. araucana (Mol.) Koch and A. angustifolia (Bert.) O. Kutz : A Comparative Study. PLANT PHYSIOLOGY 1986; 81:1062-8. [PMID: 16664944 PMCID: PMC1075486 DOI: 10.1104/pp.81.4.1062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
alpha-Amylase is one of the major enzymes present in the seeds of both Araucaria species of South America and it initiates starch hydrolysis during germination and early seedling growth. The pattern of the multiple forms of alpha-amylase of the two Araucaria species was investigated by electrophoresis and isoelectrofocusing of the native enzyme in polyacrylamide gels. The enzyme forms were compared in the embryo and megagametophyte of quiescent seeds and of seeds imbibed for 18, 48, and 90 hours. Specific alpha-amylase enzyme forms appear and disappear during these imbibition periods showing both similarities and differences between tissues and species. Before imbibition, there are five alpha-amylase forms identical in both tissues, but different between species. After 18 hours of imbibition, there are two enzyme forms in both tissues of Araucaria araucana seeds, only one form in the embryo of Araucaria angustifolia but two forms in the megagametophyte of this specie. After 48 hours of seed imbibition, most of the enzyme forms present in quiescent seeds reappear. At 90 hours of imbibition different enzyme forms are detected in the embryo with respect to the gametophyte. The changes in form patterns of alpha-amylase are discussed according to a possible regulation of gene expression by endogenous gibberellins.
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Affiliation(s)
- E Salas
- Departamento de Biología, Facultad de Ciencias, Universidad de Chile
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