Utilisation of stored lipids during germination in dimorphic seeds of euhalophyte Suaeda salsa

2018 ◽  
Vol 45 (10) ◽  
pp. 1009 ◽  
Author(s):  
Yuanqin Zhao ◽  
Yanchun Ma ◽  
Qiang Li ◽  
Yang Yang ◽  
Jianrong Guo ◽  
...  

Utilisation of stored lipids plays an important role in germination of oil seeds. In the present study, key enzyme activity (lipase, isocitrate lyase and malate synthase) in lipid utilisation was determined during germination in dimorphic seeds of euhalophyte Suaeda salsa (L.) Pall. The results revealed that the percentage of germination were highest in intertidal brown seeds, followed by inland brown seeds and then inland black seeds moistened with 0 and 300 mM NaCl during early seed germination. The same trend was found in the activity of three enzymes and soluble sugar content when seeds were moistened with 0 and 300 mM NaCl for 3 h. Salinity reduced the activity of three enzymes in inland brown and black seeds in the initial 3 h, except that salinity had no adverse effect on isocitrate lyase activity of brown seeds. Salinity had no adverse effect on three enzymes in inland brown and black seeds in the initial 30 h, except that it decreased malate synthase activity of black seeds. Salinity had no effect on three enzymes in intertidal brown seeds in the initial 3 h and 30 h. In conclusion, high activity of these enzymes in brown seeds may play an important role in utilisation of stored lipids during their rapid seed germination.

2020 ◽  
Vol 21 (4) ◽  
pp. 1431 ◽  
Author(s):  
Bin Liu ◽  
Ruqiang Lin ◽  
Yuting Jiang ◽  
Shuzhen Jiang ◽  
Yuanfang Xiong ◽  
...  

Starch is the most important form of carbohydrate storage and is the major energy reserve in some seeds, especially Castanea henryi. Seed germination is the beginning of the plant’s life cycle, and starch metabolism is important for seed germination. As a complex metabolic pathway, the regulation of starch metabolism in C. henryi is still poorly understood. To explore the mechanism of starch metabolism during the germination of C. henryi, we conducted a comparative gene expression analysis at the transcriptional level using RNA-seq across four different germination stages, and analyzed the changes in the starch and soluble sugar contents. The results showed that the starch content increased in 0–10 days and decreased in 10–35 days, while the soluble sugar content continuously decreased in 0–30 days and increased in 30–35 days. We identified 49 candidate genes that may be associated with starch and sucrose metabolism. Three ADP-glucose pyrophosphorylase (AGPase) genes, two nucleotide pyrophosphatase/phosphodiesterases (NPPS) genes and three starch synthases (SS) genes may be related to starch accumulation. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to validate the expression levels of these genes. Our study combined transcriptome data with physiological and biochemical data, revealing potential candidate genes that affect starch metabolism during seed germination, and provides important data about starch metabolism and seed germination in seed plants.


1979 ◽  
Vol 34 (12) ◽  
pp. 1232-1236 ◽  
Author(s):  
Wolfram Koller ◽  
Jürgen Frevert ◽  
Helmut Kindi

Seeds of cucumber fruits at a late stage of ripening were analyzed for microbodies and micro­body components. On isopycnic density gradient centrifugation of homogenates in the presence of EDTA, several particulate fractions were obtained: a light membraneous fraction (density d = 1.09-1.11 kg × 1-1), a mitochondria-enriched fraction (d = 1.21 kg × 1-1), a microbody-enriched fraction (d = 1.23 kg × 1-1), and a protein body fraction (d= 1.26 - 1.29 kg × 1-1). Microbo­dies were revealed by exactly coinciding peaks of malate synthase, catalase and crotonase; small proportions of citrate synthase and malate dehydrogenase were also present in this zone. Isocitrate lyase activity, however, did not occur in the seeds at this stage. The examination of enzyme activi­ties indicated the presence of microbodies which cannot function as competent glyoxysomes be­cause of the lack of isocitrate lyase. Moreover, de novo synthesis from [3H] leucine could be de­monstrated for malate synthase by means of immunoprecipitation of newly synthesized malate synthase and subsequent electrophoretic analysis.


2009 ◽  
Vol 19 (2) ◽  
pp. 91-101 ◽  
Author(s):  
Tahereh Nezamdoost ◽  
Fatemeh Tamaskani ◽  
Ahmad Abdolzadeh ◽  
Hamid Reza Sadeghipour

AbstractTo understand the beneficial effects of cold conditions during the alleviation of dormancy of walnut (Juglans regiaL.), lipid mobilization, gluconeogenesis and changes related to ageing were compared in dormant kernels incubated in the cold and under deteriorating warm conditions. Stratifying kernels at 5°C for 30 d enhanced their germination capacity, whereas warm-incubated (27°C) kernels turned rancid after 20 d and had reduced germination. Kernel imbibition was sufficient to bring about lipid mobilization, irrespective of temperature of incubation. Although imbibed kernels displayed high isocitrate lyase activity, starch and soluble sugar accumulation occurred only under cold conditions. Deteriorative 64 kDa fatty acyl-ester hydrolase activity declined in cold-stratified kernels. Cold treatment also led to reduced lipid peroxidation and hydrogen peroxide in kernels. The activity of NADP+-isocitrate dehydrogenase, an NADPH-generating enzyme, declined in warm-incubated kernels. Thus, warm-incubated kernels undergo ageing associated with oxidative stress, but there are beneficial effects of cold stratification in preventing deteriorative ageing-related processes. Imbibition is sufficient to allow lipid mobilization to occur in dormant walnut kernels, although cold stratification accompanied by gluconeogenesis is essential for kernel germination.


2015 ◽  
Vol 25 (3) ◽  
pp. 335-344 ◽  
Author(s):  
Jianrong Guo ◽  
Shanshan Suo ◽  
Bao-Shan Wang

AbstractSuaeda salsa is an annual herbaceous euhalophyte in the family Chenopodiaceae that produces dimorphic seeds on the same plant under natural conditions. In order to determine the effect of salinity on seed quality traits during seed formation, seeds from plants grown under control conditions and on 200 mM NaCl were used to investigate the effect of NaCl on seed production and seed germination. Results showed that size and weight of both black and brown seeds generated from 200 mM NaCl-treated plants were markedly greater than those from controls. The germination percentage of brown seeds from both control and NaCl-treated plants was higher than that of black seeds. Furthermore, the germination percentage of the black seeds generated from 200 mM NaCl-treated plants was significantly higher than that of the control at different concentrations of NaCl, although germination percentage declined with the increase NaCl concentration. Surprisingly, NaCl did not affect germination of the brown seeds. The germination index and vigour index of both black and brown seeds from the control plants were significantly lower than those of seeds from the different NaCl treatments. Seed starch, soluble sugar, protein and lipid content of both black and brown seeds generated from the 200 mM NaCl-treated plants were significantly higher than those from the control. These results suggest that a certain concentration of NaCl plays a pivotal role in seed vitality of the euhalophyte S. salsa through increasing seed weight and contents of storage compounds such as protein, starch and fatty acids.


2021 ◽  
Vol 12 ◽  
Author(s):  
Hao Zhang ◽  
Mingfang Hu ◽  
Hongyuan Ma ◽  
Li Jiang ◽  
Zhenyong Zhao ◽  
...  

The period between seed germination and seedling establishment is one of the most vulnerable stages in the life cycle of annuals in the saline environments. Although germination characteristics of Suaeda salsa seeds have been reported, the comparative germination patterns of dimorphic seeds and seedling growth to different abiotic stresses remain poorly understood. In this study, germination responses of dimorphic seeds to light and temperature were compared. Meanwhile, responses of dimorphic seeds and thereafter seedlings of S. salsa to different concentrations of NaCl and Na2SO4 were also tested. The results showed that the light did not significantly affect germination percentage of brown seeds, but significantly promoted germination of black seeds. Brown seeds could reach high germination percentage over a wide temperature range, however, germination of black seeds gradually increased with the increase of temperature. Brown seeds had higher germination percentage and velocity than black seeds under the same salt conditions. However, black seeds had higher recovery germination than brown seeds when transferred to deionized water. Young seedlings had lower salt tolerance than germinating seeds. At the same concentrations, Na2SO4 had stronger inhibitory effect on seed germination and seedling growth than NaCl. This study comprehensively compared germination traits of dimorphic seeds and seedling growth of S. salsa, and then developed a conceptual model to explain their adaptation to harsh saline environment.


AMB Express ◽  
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Heqin Li ◽  
Haiwang Yue ◽  
Li Li ◽  
Yu Liu ◽  
Haiyan Zhang ◽  
...  

AbstractCrop performance is seriously affected by high salt concentrations in soils. To develop improved seed pre-sowing treatment technologies, it is crucial to improve the salt tolerance of seed germination. Here, we isolated and identified the strain Bacillus sp. MGW9 and developed the seed biostimulant MGW9. The effects of seed biopriming with the seed biostimulant MGW9 in maize (Zea mays L.) under saline conditions were studied. The results show that the strain Bacillus sp. MGW9 has characteristics such as salt tolerance, nitrogen fixation, phosphorus dissolution, and indole-3-acetic acid production. Seed biopriming with the seed biostimulant MGW9 enhanced the performance of maize during seed germination under salinity stress, improving the germination energy, germination percentage, shoot/seedling length, primary root length, shoot/seedling fresh weight, shoot/seedling dry weight, root fresh weight and root dry weight. Seed biostimulant MGW9 biopriming also alleviated the salinity damage to maize by improving the relative water content, chlorophyll content, proline content, soluble sugar content, root activity, and activities of superoxide dismutase, catalase, peroxidase and ascorbate peroxidase, while decreasing the malondialdehyde content. In particular, the field seedling emergence of maize seeds in saline-alkali soil can be improved by biopriming with the seed biostimulant MGW9. Therefore, maize seed biopriming with the seed biostimulant MGW9 could be an effective approach to overcoming the inhibitory effects of salinity stress and promoting seed germination and seedling growth.


2005 ◽  
Vol 187 (4) ◽  
pp. 1415-1425 ◽  
Author(s):  
Michael Meister ◽  
Stephan Saum ◽  
Birgit E. Alber ◽  
Georg Fuchs

ABSTRACT Cell extracts of Rhodobacter capsulatus grown on acetate contained an apparent malate synthase activity but lacked isocitrate lyase activity. Therefore, R. capsulatus cannot use the glyoxylate cycle for acetate assimilation, and a different pathway must exist. It is shown that the apparent malate synthase activity is due to the combination of a malyl-coenzyme A (CoA) lyase and a malyl-CoA-hydrolyzing enzyme. Malyl-CoA lyase activity was 20-fold up-regulated in acetate-grown cells versus glucose-grown cells. Malyl-CoA lyase was purified 250-fold with a recovery of 6%. The enzyme catalyzed not only the reversible condensation of glyoxylate and acetyl-CoA to l-malyl-CoA but also the reversible condensation of glyoxylate and propionyl-CoA to β-methylmalyl-CoA. Enzyme activity was stimulated by divalent ions with preference for Mn2+ and was inhibited by EDTA. The N-terminal amino acid sequence was determined, and a corresponding gene coding for a 34.2-kDa protein was identified and designated mcl1. The native molecular mass of the purified protein was 195 ± 20 kDa, indicating a homohexameric composition. A homologous mcl1 gene was found in the genomes of the isocitrate lyase-negative bacteria Rhodobacter sphaeroides and Rhodospirillum rubrum in similar genomic environments. For Streptomyces coelicolor and Methylobacterium extorquens, mcl1 homologs are located within gene clusters implicated in acetate metabolism. We therefore propose that l-malyl-CoA/β-methylmalyl-CoA lyase encoded by mcl1 is involved in acetate assimilation by R. capsulatus and possibly other glyoxylate cycle-negative bacteria.


2021 ◽  
Vol 22 (4) ◽  
pp. 1562
Author(s):  
Jia Zhao ◽  
Wenjun Li ◽  
Shan Sun ◽  
Liling Peng ◽  
Zhibo Huang ◽  
...  

Seed vigor affects seed germination and seedling emergence, and therefore is an important agronomic trait in rice. Small auxin-up RNAs (SAURs) function in a range of developmental processes, but their role in seed vigor remains unclear. Here, we observed that disruption of OsSAUR33 resulted in reduced germination rates and low seed uniformity in early germination. Expression of OsSAUR33 was higher in mature grains and early germinating seeds. RNA-seq analysis revealed that OsSAUR33 modulated seed vigor by affecting the mobilization of stored reserves during germination. Disruption of OsSAUR33 increased the soluble sugar content in dry mature grains and seeds during early germination. OsSAUR33 interacted with the sucrose non-fermenting-1-related protein kinase OsSnRK1A, a regulator of the sugar signaling pathway, which influences the expression of sugar signaling-related genes during germination. Disruption of OsSAUR33 increased sugar-sensitive phenotypes in early germination, suggesting OsSAUR33 likely affects seed vigor through the sugar pathway. One elite haplotype of OsSAUR33 associated with higher seed vigor was identified mainly in indica accessions. This study provides insight into the effects of OsSAUR33 on seed vigor in rice.


1999 ◽  
Vol 181 (23) ◽  
pp. 7161-7167 ◽  
Author(s):  
Kerstin Höner Zu Bentrup ◽  
Andras Miczak ◽  
Dana L. Swenson ◽  
David G. Russell

ABSTRACT Analysis by two-dimensional gel electrophoresis revealed thatMycobacterium avium expresses several proteins unique to an intracellular infection. One abundant protein with an apparent molecular mass of 50 kDa was isolated, and the N-terminal sequence was determined. It matches a sequence in the M. tuberculosisdatabase (Sanger) with similarity to the enzyme isocitrate lyase of both Corynebacterium glutamicum and Rhodococcus fascians. Only marginal similarity was observed between this open reading frame (ORF) (termed icl) and a second distinct ORF (named aceA) which exhibits a low similarity to other isocitrate lyases. Both ORFs can be found as distinct genes in the various mycobacterial databases recently published. Isocitrate lyase is a key enzyme in the glyoxylate cycle and is essential as an anapleurotic enzyme for growth on acetate and certain fatty acids as carbon source. In this study we express and purify Icl, as well as AceA proteins, and show that both exhibit isocitrate lyase activity. Various known inhibitors for isocitrate lyase were effective. Furthermore, we present evidence that in both M. avium and M. tuberculosis the production and activity of the isocitrate lyase is enhanced under minimal growth conditions when supplemented with acetate or palmitate.


1970 ◽  
Vol 16 (12) ◽  
pp. 1199-1203 ◽  
Author(s):  
A. Donawa ◽  
W. E. Inniss

Acetate-grown Bacillus megaterium KM possessed high isocitrate lyase and malate synthase activity as compared to glucose-grown cells. Chloramphenicol prevented the increase in isocitrate lyase activity when cells were transferred from glucose to acetate media, indicating that such an increase in activity was probably due to de novo protein synthesis.The affinity of the substrate, isocitrate, was greater for isocitrate dehydrogenase than for isocitrate lyase. Phosphoenolpyruvate was found to inhibit isocitrate lyase non-competitively. The concerted action of glyoxylate and oxaloacetate was capable of inhibiting isocitrate dehydrogenase. The role such factors play in the balancing of the tricarboxylic acid cycle and the glyoxylate pathway in the microorganism is considered.


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