Transcriptomic analysis of salt stress induced chlorophyll biosynthesis-related genes in photoheterotrophic Arabidopsis thaliana calli.

In order to investigate the salt stress induced chlorophyll biosynthesis-related genes in photoheterotrophic cultures, we performed RNA-Seq analysis on A. thaliana calli exposed to 100 mM NaCl on MS medium containing 0.5 mg/L 2,4-D 30 days. Four different conditions of samples were sequenced on Illumina HiSeq Platform in total and generated about 4.49 Gb per sample. The average genome and gene mapping rates were 93.52% and 90.78%, respectively. According to expression profile analysis, some DEGs demonstrated altered related to chlorophyll pigment metabolism. According to analysis, green callus color of photoheterotrophic calli were mainly connected with the induction of LHCB4.3 light harvesting complex photosystem II (Gene ID:818599), AT1G49975 photosystem I reaction center subunit N (Gene ID: 841421), PAM68 PAM68-like protein (DUF3464) (Gene ID: 2745715) and AT3G63540 thylakoid lumenal protein (Mog1/PsbP/DUF1795-like photosystem II reaction center PsbP family protein)(Gene ID: 7922413) genes. Furthermore, 8 DEGs were randomly selected to validate the transcriptome profiles via qPCR. These results will provide a foundation for further studies aimed at giving photosynthetic properties to in vitro plant cultures.

Molecular Effects of Silicon on Arabidopsis thaliana Seedlings under UV-B Stress.

Silicon-plant interaction studies have shown that silicon reduces the harmful effects of stress in plants. Ultraviolet-B (UV-B) radiation, one of the abiotic stress affecting plants, poses a severe problem due to global warming. In this context, it is crucial to examine silicon's effects on UV-B radiation stress at the molecular level. The experiments were carried out on 17 days old Arabidopsis seedlings that were treated with 800 µWatt cm-2 doses of UV-B for 60 min and harvested on the 28th day. 1 mM orthosilicic acid was applied to the in vitro plant tissue culture for experimental groups. According to the results of the osmolyte accumulation analyses, silicon has been shown to play a role in the osmotic stress response. Gene expression levels of DGK2, CHS, FLC, RAD51, and UVR8 were measured via qPCR, and it has been shown that silicon interacts with these genes under UV-B radiation stress. The result of genomic DNA methylation analysis demonstrated that silicon might affect DNA methylation levels by increasing the 5-mC percentage compared with the control group. This study focused on the molecular effects of silicon application. It supports silicon-plant interaction research by demonstrating that silicon might affect UV-B response at the molecular level.

Epigenetic memory and priming in plants.

In nature, plants are regularly exposed to biotic and abiotic stress conditions. These conditions create potential risks for survival. Plants have evolved in order to compete with these stress conditions through physiological adjustments that are based on epigenetic background. Thus, the ecological signals create different levels of stress memory. Recent studies have shown that this stress-induced environmental memory is mediated by epigenetic mechanisms that have fundamental roles in the aspect of controlling gene expression via DNA methylation, histone modifications and, small RNAs and these modifications could be transmitted to the next generations. Thus, they provide alternative mechanisms to constitute stress memories in plants. In this review, we summarized the epigenetic memory mechanisms related with biotic and abiotic stress conditions, and relationship between priming and epigenetic memory in plants by believing that it can be useful for analyzing memory mechanisms and see what is missing out in order to develop plants more resistant and productive under diverse environmental cues.

Genetic, Morphological, and Biochemical Diversity of Argan Tree (Argania spinosa L.) (Sapotaceae) in Tunisia.

Argan trees are normally endemic to Morocco and Algeria, but hundreds of argan trees exist in Tunisia, some introduced from Morocco and some from unknown origins. The aim of the present study was to evaluate the genetic, morphological, and biochemical diversity of the argan trees in Tunisia. In this study, we used morphometric data collected from vegetative tissue, as well as pomological characteristics related to fruits, stones, and kernels. Genetic variation in 60 trees of Tunisian Argania spinosa L. was estimated using inter-simple sequence repeats (ISSRs). Mutation screening and genotyping by high-resolution melting (HRM) was performed to detect delta-6-desaturase (D6D) variants in the tested individuals, and finally fatty acid analysis of argan leaves with gas chromatography (GC) was performed. The plant materials used in this study originated from four different sites in Tunisia. Analysis of morphological characteristics showed large variability both within and between the studied collections. The analysis of ISSR polymorphisms gave information about the diversity within and between populations. HRM analysis showed that all 60 argan individuals were grouped into 10 different categories. The results of the gas chromatography analysis showed that the presence of omega-3 fatty acids EPA and DHA was noticeable in some argan leaves.

Molecular cloning and biotic elicitation response of phenylalanine ammonia-lyase gene of Astragalus chrysochlorus.

Phenylalanine ammonia lyase (PAL) is the first enzyme of the phenylpropanoid pathway, and it is necessary to upregulate flavonoid biosynthesis in most of the plant species. In this study, we have cloned PAL gene from endemic Astragalus chrysochlorus which is a producer of phenolic nicotiflorin (kaempferol-3-O-rutinoside). The cDNA encoding PAL was cloned from A. chrysochlorus using RT-PCR (reverse transcription-polymerase chain reaction) with conserved primer pairs. Amino acid sequence alignments showed that AcPAL (2160 bp, Accession number: KM189182) has more than 95% amino acid identity with their homologues in other Astragalus species. The coding sequence for the protein of AcPAL is 720 amino acids with a calculated molecular weight of 78.53 kDa. Full length AcPAL was cloned and expressed in Escherichia coli. qPCR (quantitative real-time PCR) analysis of the expression of PAL gene of A. chrysochlorus suggested that maximum transcript level was observed in 3 h yeast extract elicited suspension cells. Our findings suggest that AcPAL plays role in early response for yeast extract treatment. The isolation of AcPAL gene could be result in further studies for overproduction of secondary metabolite, nicotiflorin.

The effects of pesticide exposure on serum total sialic acid levels.

Pesticides used to increase agricultural production have hazard effects for human being health. The present study reports the serum levels of total sialic acid (TSA) in the pesticide applicators in the agriculture areas of the Kahramanmaras, Turkiye. This study included a total of 79 volunteer individuals. Pesticide group included 47 men who were working as pesticide applicators. Control group comprised healthy males (n=32), nonsmokers and nondrinkers and also nonexposured to pesticide and other chemicals chronically. Serum TSA level was measured with the Warren method modified by Pönniö et al. The TSA concentrations were significantly higher in the pesticide groups (p < 0.001) than those of control subjects. We can conclude from the results obtained that serum TSA was affected by pesticide exposure. This finding may be an indication of harmful effects of pesticides. Increased serum TSA levels in pesticide exposure might be related to various diseases e.g. various cancers, which are also often associated with elevated serum TSA levels. However further studies are necessary to evaluate the concentrations of serum TSA in pesticide exposure.