bioRxiv Science⌕ Search

bioRxiv · 10.1101/219840

Effects of polyploidy on response of Dunaliella salina to salinity

Abstract

In this study, effect of different percentages of polyploid cells of Dunaliella salina in culture medium, on growth and other biochemical parameters of algae under different salinity levels were investigated. The results indicated that concentration 3M NaCl is the optimal concentration of salt, since in this concentration, the highest enhancement in fresh and dry weight, chlorophyll and carotenoids, soluble sugar, glycerol, protein and starch content was observed in comparison with other concentrations. The amount of these metabolites declined in the concentrations under the optimum salinity. The least and highest amounts of MDA were observed at 1 and 4 M NaCl respectively. Polyploidy in optimum concentration of salt, caused further increment of the above growth parameters. In this relation, in most cases, treatment of 0.1% was more effective. The beneficial effects of polyploidy in non-optimal conditions were also found in some parameters such as biomass, chlorophyll, carotenoids, proteins and starch. The activity of antioxidant enzymes CAT, SOD and POD were maximum in 4 M NaCl. Polyploidy affected activity of these antioxidant enzymes in some concentrations of salt. Overall, our results suggest that the microalgae have significantly different responses to salt stress based on ploidy level of the algae.\n\nAbbreviations

Source connections

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Mansouri, H., Soltani Nezhad, F.. 2017-11-15. Effects of polyploidy on response of Dunaliella salina to salinity. https://doi.org/10.1101/219840

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

Secondary growth in the tomato stem is suppressed by the flowering regulators FUL2 and STM3

Herbaceous eudicot crops such as tomato accumulate substantial amounts of secondary xylem in their stems, particularly in the basal part. As plants progress from the vegetative phase to flowering and fruit development, secondary growth continues to provide mechanical support and facilitate transport. To uncover how secondary growth is regulated in the tomato stem, we used laser capture microdissection RNA-seq to establish tissue-specific transcriptomic profiles. This revealed that key regulators associated with wood formation in poplar are also acting in tomato. Furthermore, we found that the flowering regulators FUL2 and STM3 are substantially expressed in xylem tissue. Subsequent functional analysis identified FUL2 and STM3 as key repressors of secondary growth, with ful2 or stm3 knock-out mutants exhibiting strongly increased secondary growth in older tomato stems. Notably, a higher order mutant in which both ful2 and stm3 were knocked out displays a similar non-additive phenotype, indicating, together with yeast two-hybrid data showing physical interaction, that FUL2 and STM3 act together in a complex. The expression levels of both genes remain low until after the floral transition but strongly rise during subsequent stem development. Transcriptomic analyses in ful2, stm3, and wild-type stems at stages before and after detectable anatomical differences, showed that the FUL2-STM3 complex represses distinct sets of NAC and MYB candidate regulators associated with xylem development. Interestingly, FUL2 and STM3 control these regulators in a stage- and position-dependent way, with candidates showing upregulation only at later stages in mid-height stems being already upregulated at earlier stages in basal stem regions. Our findings provide a tissue-resolved transcriptomic resource for tomato stems and reveal a role for FUL2 and STM3 in limiting secondary xylem accumulation as stem development progresses.

plant biology↗

Geometric Morphometrics of Pistillate Flowers in Astrocaryum sect. Huicungo (Arecaceae): Taxonomic Implications for the Peruvian Species

The taxonomy of the Amazonian palm clade Astrocaryum sect. Huicungo remains controversial due to deep discordances between traditional classifications based on qualitative floral traits and recent phylogenomic evidence. To address this, landmark-based two-dimensional geometric morphometrics (4 landmarks, 16 semilandmarks) was applied to evaluate the symmetric component of shape variation in calyx and corolla structures across 549 pistillate flowers from the 11 Peruvian species. Although multivariate analyses (PCA, CVA) revealed continuous morphological variation and extensive phenotypic overlap, perianth geometry retained a significant diagnostic signal. Cross-validated classification rates demonstrated that the corolla exhibited higher discriminatory power than the calyx, while the combined perianth analysis (calyx + corolla) maximized taxonomic assignment accuracy. Furthermore, Mahalanobis distance-based clustering did not replicate traditional subsections: A. chonta and A. ulei exhibited divergent architectures, whereas A. carnosum, A. faranae, and A. huicungo shared profound geometric similarity. This study demonstrates that quantitative perianth morphometrics is a valuable tool for species delimitation in Astrocaryum, supporting the re-evaluation of traditional taxonomic boundaries through an integrative approach.

plant biology↗

Multi-Criteria Evaluation of Hibiscus mutabilis Cultivars for Food Development Using Delphi and Analytic Hierarchy Process

This study evaluated 11 Hibiscus mutabilis cultivars from Chengdu Botanical Garden to assess their quality for food use and identify promising cultivars. An evaluation framework was developed using the Delphi method to select indicators and the analytic hierarchy process (AHP) to determine their weights. Overall scores ranged from 2.5785 to 3.6043, and the cultivars were classified into three grades. Grade I included Hibiscus mutabilis 'Bairi Huacai', Hibiscus mutabilis 'Chongbanbai' and Hibiscus mutabilis 'Jinqiusong'; Grade II included Hibiscus mutabilis 'Jinqiuhong', Hibiscus mutabilis 'Zuifurong', Hibiscus mutabilis 'Danbanhong', Hibiscus mutabilis 'Jinxiuzi', Hibiscus mutabilis 'Jinbiyu' and Hibiscus mutabilis 'Caixia'; whereas Grade III included Hibiscus mutabilis 'Mudanfen' and Hibiscus mutabilis 'Jinrui'. In summary, Hibiscus mutabilis 'Bairi Huacai', Hibiscus mutabilis 'Chongbanbai' and Hibiscus mutabilis 'Jinqiusong' are the preferred cultivars for food processing and development. The framework provides a basis for cultivar screening and further evaluation of H. mutabilis flowers for food use.

plant biology↗