scholarly journals The Rice Alpha-Amylase, Conserved Regulator of Seed Maturation and Germination

2019 ◽  
Vol 20 (2) ◽  
pp. 450 ◽  
Author(s):  
Rebecca Damaris ◽  
Zhongyuan Lin ◽  
Pingfang Yang ◽  
Dongli He

Alpha-amylase, the major form of amylase with secondary carbohydrate binding sites, is a crucial enzyme throughout the growth period and life cycle of angiosperm. In rice, alpha-amylase isozymes are critical for the formation of the storage starch granule during seed maturation and motivate the stored starch to nourish the developing seedling during seed germination which will directly affect the plant growth and field yield. Alpha-amylase has not yet been studied intensely to understand its classification, structure, expression trait, and expression regulation in rice and other crops. Among the 10-rice alpha-amylases, most were exclusively expressed in the developing seed embryo and induced in the seed germination process. During rice seed germination, the expression of alpha-amylase genes is known to be regulated negatively by sugar in embryos, however positively by gibberellin (GA) in endosperm through competitively binding to the specific promoter domain; besides, it is also controlled by a series of other abiotic or biotic factors, such as salinity. In this review, we overviewed the research progress of alpha-amylase with focus on seed germination and reflected on how in-depth work might elucidate its regulation and facilitate crop breeding as an efficient biomarker.

Author(s):  
Qi Zhang ◽  
Yuanxuan Peng ◽  
Xiumei Li ◽  
Bingxian Chen ◽  
Jun Liu

The purpose of this study was to explore the relationship between β-galactosidase and rice seed germination. Exogenous β-galactosidase (1 U) facilitated germination while abscisic acid (ABA) delayed germination. Histo­chemical staining and spectrophotometry revealed that the activity of endogenous β-galactosidase increased gradually during germination. 1 µM ABA and GA4+7 could, respectively, inhibit and promote the activity of β-galactosidase in the rice embryo. This indicated that the regulation of rice seed germination by these two phytohormones may be through mediation of β-galactosidase activity. During seed germination, the transcriptional expressions of OsBAGL1, OsBAGL4, OsBAGL8 and OsBAGL11 were higher than those of other homologous genes, suggesting that these four genes may be involved in the germination process. GA4+7 significantly increased the expression of the above four genes. By contrast, the transcriptional expression of OsBAGL8 and OsBAGL11 were significantly reduced by ABA, but not that of OsBAGL1 and OsBAGL4. Our study has important theoretical and practical significance for illustrating the relationship between β-galactosidase and seed germination.


Rodriguésia ◽  
2016 ◽  
Vol 67 (3) ◽  
pp. 661-666
Author(s):  
João Fabrício Mota Rodrigues ◽  
Sâmia Paiva de Oliveira

Abstract Ingestion of seeds by vertebrates may influence seed germination and dispersion. However the mechanisms responsible by these effects and the importance of turtles in these interactions are still poorly understood. This study aims to evaluate how Chelonoidis carbonarius influences the germination process of Leucaena leucocephala using an experiment conducted at the Federal University of Ceará, Fortaleza-CE, Brazil, that simulates the passage of the seeds of this plant through the digestive tract of C. carbonarius: stomach acidic condition and seeds sown in feces. We demonstrated that sowing the seeds in feces of Chelonoidis carbonarius has a negative effect on the germination of Leucaena leucocephala, decreasing the germination speed index of the seeds, while the acidic conditions have a neutral one. This study is a first attempt to understand how turtles and tortoises may influence the seed germination, and the implications of these findings in natural environments deserve further investigations.


2008 ◽  
Vol 32 (1) ◽  
pp. 19-25 ◽  
Author(s):  
Renata Braga Souza Lima ◽  
José Francisco de Carvalho Gonçalves ◽  
Silvana Cristina Pando ◽  
Andréia Varmes Fernandes ◽  
André Luis Wendt dos Santos

This study aimed to characterize protein, oil, starch and soluble sugar mobilization as well as the activity of alpha-amylase during rosewood seed germination. Germination test was carried out at 25°C and the following parameters were analyzed: percentage of germination, initial, average, and final germination time. Seed reserve quantification was monitored in quiescent seeds and during different stages of radicle growth. Starch mobilization was studied in function of a-amylase activity. Germination reached 87.5% at the initial, average, and final time of 16, 21 and 30 days, respectively. Oil mobilization showed a negative linear behavior, decreasing 40% between the first and the last stage analyzed, whereas protein levels increased 34.7% during the initial period of germination. Starch content (46.4%) was the highest among those of the metabolites analyzed and starch mobilization occurred inversely to the observed for soluble sugars; alpha-amylase activity increased until the 15th day, a period before radicle emission and corresponding to the highest starch mobilization. The high percentage of rosewood seed germination may be related to the controlled condition used in the germination chamber as well as to high seed reserve mobilization, in special oil and starch.


2014 ◽  
Vol 7 (21) ◽  
pp. 4547-4552 ◽  
Author(s):  
Febri Doni ◽  
I. Anizan ◽  
C.M.Z. Che Radziah ◽  
Ahmad Hilmi Salman
Keyword(s):  

2017 ◽  
Vol 2 (51) ◽  
pp. 114-122
Author(s):  
A. Habibi ◽  
◽  
B.K. Zayadan ◽  
A. Baizhigitova ◽  
S. Alemyar ◽  
...  

2018 ◽  
pp. 52-58

Purificación Parcial y Caracterización de Alfa Amilasa de granos germinados de Chenopodium quinoa (Quinua) Partial Purification and Characterization of Alpha Amylase from germinated grains from Chenopopdium quinoa (Quinua) Melissa Bedón Gómez, Oscar Nolasco Cárdenas, Carlos Santa Cruz C. y Ana I. F. Gutiérrez Román Universidad Nacional Federico Villarreal, Facultad de Ciencias Naturales y Matemática, Laboratorio de Bioquímica y Biología Molecular, Jr. Río Chepén S/N, El Agustino. Telefax: 362 - 3388 DOI: https://doi.org/10.33017/RevECIPeru2013.0007/ Resumen Las alfa amilasas son las enzimas más estudiadas e importantes en el campo biotecnológico e industrial; ya que han reemplazado por completo la hidrólisis química del almidón. Estas enzimas son imprescindibles en la elaboración de productos alimenticios, combustibles, medicamentos y detergentes con la finalidad de optimizar procesos y conservar el medio ambiente. La α-amilasa puede ser purificada de diferentes organismos como plantas, animales, hongos y bacterias; actualmente un gran número de α-amilasas bacterianas en especial del género Bacillus están disponibles comercialmente y son las más utilizadas en las industrias. Sin embargo, la producción de éstas no satisfacen los requerimientos industriales en el mundo; ya que, la demanda de esta enzima se ha incrementado en los últimos dos años y el empleo de α-amilasas bacterianas ha provocado alergias afectando al 15% de la población a nivel mundial. . En este estudio, como fuente de α-amilasa se emplearon semillas de Chenopodium quinoa (quinua) var hualhuas blanca durante el proceso de germinación; esta enzima fue parcialmente purificada por precipitación con sulfato de amonio obteniendo una actividad específica final de 35.60U/mg y un grado de purificación de 5 veces. La purificación fue confirmada por SDS-PAGE, encontrando un peso molecular de 44kDa. La actividad enzimática se evaluó mediante el método de Miller mostrando máxima actividad a pH 7 y a temperatura de 37ºC. La linealización de Lineweaver-Burk nos dio un Km de 16mg/mL y Vmax de 100µM de maltosa/min. Por lo tanto, esta caracterización reúne los pre-requisitos necesarios para la aplicación en la industria. Descriptores: Chenopodium quinoa, alfa amilasa, germinación, purificación parcial. Abstract The alpha amylases are the enzymes most studied and important in biotechnology and industry; because they have completely replaced the starch’s chemical hydrolysis. These enzymes are essential in the food production, medicines and detergents in order to optimize processes and conserve the environment. The α-amylase can be isolated from different organisms such as plants, animals, fungi and bacteria, now a large number of bacterial α-amylases especially from genus Bacillus are commercially available and they are the most used in industry. However, the production of these do not meet industry requirements in the world, because the demand for this enzyme has increased in the last two years and the use of bacterial α-amilase has caused allergies affecting the 15% of the global population. In this study, as a source of α-amylase used the seeds from Chenopodium quinoa (quinoa). Var. white hualhuas during the germination process, this enzyme was partially purified by ammonium sulfate precipitation to obtain a final specific activity of 35.60U/mg, and a grade of purification of 5 times. The purification was confirmed by SDS-PAGE, where the molecular weight was 44kDa. The enzyme activity was evaluated by Miller method showing maximum activity at pH 7 and 37ºC. The Lineweaver-Burk linearization shows a Km of 16mg/mL and Vmax of 100μM the maltose / min. Therefore, these characterizations meet the prerequisites need for industry. Keywords: Chenopodium quinoa; alpha amylase; germination; partial purification


Author(s):  
S. N. Mahadi ◽  
F. Zawawi ◽  
R. Nulit ◽  
M. H. Ibrahim ◽  
N. I. Ab. Ghani

Aim: This study was conducted to develop liquid enhancer containing KCl, TU, GA, and SA for germination of drought-stressed Oryza sativa subsp. indica cv. MR284 seed. Study Design: All experiments were conducted in a completely randomized design. Two steps were involved in the development process which are to select an ideal concentration for each KCl, TU, GA, and SA, and to find an ideal combination of chemicals from the selection of ideal concentrations acquired in step 1 to form liquid enhancer. There were 20 treatments for step 1 and 9 treatments for step 2. All of these treatments with 6 replicates. Place and Duration of Study: Department of Biology, Faculty of Science, University Putra Malaysia, between June 2018 and December 2018. Methodology: The sterilized rice seed cv. MR284 was stressed in the -1.2 Mpa PEG 6000 solution for three days and germinated in the KCl, TU, GA, and SA solution in a series of concentration for 10 days, in a controlled room. Seed germination was observed daily. Results: In the first step, drought-stressed rice seed showed the best germination performance in the 30 mM of KCl, 2.0 mM of TU, 0.24 mM GA, and 0.5 mM SA. Meanwhile, in the second step, the drought-stressed rice seed showed the best germination performance in the combination of 30 mM KCl + 2.0 mM TU + 0.24 mM GA + 0.5 mM SA. The best germination performance was evaluated by the highest germination percentage (%), germination index, seed vigor, leaf length, root length and biomass. Conclusion: Therefore, the combination treatments of 30 mM KCl + 2.0 mM TU + 0.5 mM SA was found to be the most effective and simplest liquid enhancer formula that has an ability to enhance seed germination of drought-stressed rice cv. MR284 seed.


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