| 1. |
- Boussora, Faiza, et al.
(författare)
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Spike developmental stages and ABA role in spikelet primordia abortion contribute to the final yield in barley (Hordeum vulgare L.)
- 2019
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Ingår i: Botanical Studies. - : Springer Science and Business Media LLC. - 1999-3110. ; 60:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: Salinity is a significant environmental stress factor limiting crops productivity. Barley (Hordeum vulgare L.) has a natural tolerance to salinity stress, making it an interesting study object in stress biology research. In the present study, for the first time the effect of salinity stress on barley inflorescence developmental stages was investigated. Five spring barley genotypes irrigated with saline water (12.5 ds/m NaCl) were compared to controls treated with normal tap water. We measured abscisic acid (ABA) concentrations in the apical, central and basal sections of the immature inflorescence at green anther (GA) stage. The role of ABA in spikelet primordia development, atrophy and abortion and final yield was evaluated. Results: A time course experiment starting from double ridge until green anther (GA) stages revealed that salinity reduced the length of spike developmental stages in all genotypes causing shortened of the plant life cycle. The shortened plant life cycle negatively affected plant height and number of tillers/plant. Salinity also affected spikelet primordia development. In both control and salinity treated plants apical spikelet abortion started in late awn primordium (AP) stage. However, under salinity treatment, significantly more spikelets were aborted, thus directly affecting plant yield potential. ABA, which plays a role in the spikelet/floret abortion process, was markedly elevated in the base and apex of salt treated spikes correlating with an increased spikelet abortion in these regions. Conclusions: Overall, salinity treatment reduced all plant and yield-related parameters investigated and turned some of the correlations among them from positive to negative or vice versa. Investigations of ABA role in floral development and phase duration of barley spike showed that, ABA regulates the spikelet/floret abortion process affecting the yield potential under salinity and control conditions.
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| 2. |
- Othman, Nor Zalina, et al.
(författare)
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Aeration rate effect on the growth kinetics, phytase production and plasmid stability of recombinant Escherichia coli BL21 (DE3)
- 2014
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Ingår i: Journal of Pure and Applied Microbiology. - 0973-7510. ; 8:4, s. 2721-2728
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Tidskriftsartikel (refereegranskat)abstract
- Phytase production using Escherichia coli BL21 (DE3), a recombinant strain harboring a plasmid encoding thermostable Bacillus phytase, in semi-industrial scale was studied in this work. Among the factors needed to be considered in order to achieve high enzyme yield, aeration rate plays an important role. Suitable aeration is required to supply cells with sufficient amount of air for cell and phytase production. The effect of different aeration rates, (1.0, 2.0 and 3.0 vv-1min-1), on the kinetics of cell growth and phytase production by the recombinant E. coli BL21 (DE3) in 16-L pilot scale stirred tank bioreactor was investigated. The highest cell concentration of 3.81 gL-1 concomitant with the maximal total phytase production of 15.63 UmL-1 were obtained in a bioreactor of aeration rate 3.0vv-1min-1. At this high aeration rate, a maximal specific growth rate (μmax) and the maximal specific phytase production of 0.33 h-1 and 4102Ug-1, respectively, were achieved.
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| 3. |
- Sayed, Mohammed A., et al.
(författare)
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Analyses of mads‐box genes suggest hvmads56 to regulate lateral spikelet development in barley
- 2021
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Ingår i: Plants. - : MDPI AG. - 2223-7747. ; 10:12
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Tidskriftsartikel (refereegranskat)abstract
- MADS‐box transcription factors are crucial regulators of inflorescence and flower development in plants. Therefore, the recent interest in this family has received much attention in plant breeding programs due to their impact on plant development and inflorescence architecture. The aim of this study was to investigate the role of HvMADS‐box genes in lateral spikelet development in barley (Hordeum vulgare L.). A set of 30 spike‐contrasting barley lines were phenotypically and genotypically investigated under controlled conditions. We detected clear variations in the spike and spikelet development during the developmental stages among the tested lines. The lateral flo-rets in the deficiens and semi‐deficiens lines were more reduced than in two‐rowed cultivars except cv. Kristina. Interestingly, cv. Kristina, int‐h.43 and int‐i.39 exhibited the same behavior as def.5, def.6, semi‐def.1, semi‐def.8 regarding development and showed reduced lateral florets size. In HOR1555, HOR7191 and HOR7041, the lateral florets continued their development, eventually setting seeds. In contrast, lateral florets in two‐rowed barley stopped differentiating after the awn primordia stage giving rise to lateral floret sterility. At harvest, the lines tested showed large variation for all central and lateral spikelet‐related traits. Phylogenetic analysis showed that more than half of the 108 MADS‐box genes identified are highly conserved and are expressed in different barley tissues. Re-sequence analysis of a subset of these genes showed clear polymorphism in either SNPs or in/del. Variation in HvMADS56 correlated with altered lateral spikelet morphology. This suggests that HvMADS56 plays an important role in lateral spikelet development in barley.
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