Random amplified polymorphic DNA analysis of salt-tolerant tobacco mutants generated by gamma radiation

Transcriptome Analysis of the Salt-Treated Actinidia deliciosa (A. Chev.) C. F. Liang and A. R. Ferguson Plantlets

The area of saline land in the world is quite large, and there is broad room for its development and usage. 'Xuxiang' is an Actinidia deliciosa variety that is tolerant to salt and can be planted in an area of light-saline land, and has good comprehensive characteristics and high economic value. However, the molecular mechanism of salt tolerance is unknown at present. To understand the molecular mechanism of salt tolerance, the leaves of A. deliciosa 'Xuxiang' were used as explants to establish a sterile tissue culture system, and plantlets were obtained using this system. One percent concentration (w/v) of sodium chloride (NaCl) was employed to treat the young plantlets cultured in Murashige and Skoog (MS) medium, then RNA-seq was used for transcriptome analysis. The results showed that the genes related to salt stress in the phenylpropanoid biosynthesis pathway and the anabolism of trehalose and maltose pathways were up-regulated; however, those genes in the plant hormone signal transduction and metabolic pathways of starch, sucrose, glucose, and fructose were down-regulated after salt treatment. The expression levels of ten genes that were up-regulated and down-regulated in these pathways were confirmed by real-time quantitative polymerase chain reaction (RT-qPCR) analysis. The salt tolerance of A. deliciosa might be related to the expression level changes in the genes in the pathways of plant hormone signal transduction, phenylpropanoid biosynthesis, and starch, sucrose, glucose, and fructose metabolism. The increased expression levels of the genes encoding alpha-trehalose-phosphate synthase, trehalose-phosphatase, alpha-amylase, beta-amylase, feruloyl-CoA 6-hydroxylase, ferulate 5-hydroxylase, and coniferyl-alcohol glucosyl transferase might be vital to the salt stress response of the young A. deliciosa plants.

Raman Spectroscopic and Chemometric Investigation of Lipid-Protein Ratio Contents of Soybean Mutants

Seeds belonging to fourth generation mutants (M4) of Ataem-7 cultivar (A7) variety and S04-05 (S) breeding line salt-tolerant soybeans were investigated by Raman spectroscopy, complemented by chemometrics methods, in order to evaluate changes induced by mutations in the relative lipid-protein contents, and to find fast, efficient strategies for discrimination of the mutants and the control groups based on their Raman spectra. It was concluded that gamma irradiation caused an increase in the lipid to protein ratio of the studied Ataem-7 variety mutants, while it led to a decrease of this ratio in the investigated S04-05 breeding line mutants. These results were found to be in agreement with data obtained by reflectance spectrum analysis of the seeds in the full ultraviolet to near-infrared spectral region and suggest the possibility of developing strategies where gamma irradiation can be used as a tool to improve mutant soybean plants targeted to different applications, either enriched in proteins or in lipids. Ward's clustering and principal component analysis showed a clear discrimination between mutants and controls and, in the case of the studied S-type species, discrimination between the different mutants. The grouping scheme is also found to be in agreement with the compositional information extracted from the analysis of the lipid-protein contents of the different samples.

Transcript profiling of salt tolerant tobacco mutants generated via mutation breeding

The main aim of the study is to identify the genes differentially, predominantly or specifically expressed in salt tolerant tobacco mutants, improved from Akhisar 97 and İzmir Özbaş varieties via mutation breeding, with respect to unstressed control plants. Seven tobacco mutants which have different salt tolerance capacities were evaluated by Gene Fishing analysis. Under stress conditions differentially expressed 100 reproducible bands were identified (74 of up-regulated and 20 of down-regulated while 6 were unknown). 75 of differentially expressed genes (DEGs) were successfully extracted from the gel and sequence analyses were performed. Functional annotation of the DEGs was performed against Blastn by interrogating their sequences. The 65 salt-regulated differentially expressed genes showed similarity with known genes, while 6 of DEGs didn't show any genetic similarities with known genes. DEGs were classified in eleven functional categories involving the abiotic stress response, biotic stress response, energy metabolism, cellular transport, catalitic activity, protein modification, amino acid metabolism and transcription factors. All the mutants were evaluated for their regulatory mechanisms against salt stress. The current data reveal that these six DEGs should be identified by next generation sequencing techniques and functional analysis should be design to understand the role of these six differentially expressed genes of tobacco mutants in further studies to improve new genetic resources.