N-acetyl-cysteine mitigates arsenic stress in lettuce: Molecular, biochemical, and physiological perspective.

Agricultural land contaminated with heavy metals such as non-biodegradable arsenic (As) has become a serious global problem as it adversely affects agricultural productivity, food security and human health. Therefore, in this study, we investigated how the administration of N-acetyl-cysteine (NAC), regulates the physio-biochemical and gene expression level to reduce As toxicity in lettuce. According to our results, different NAC levels (125, 250 and 500 µM) significantly alleviated the growth inhibition and toxicity induced by As stress (20 mg/L). Shoot fresh weight, root fresh weight, shoot dry weight and root dry weight (33.05%, 55.34%, 17.97% and 46.20%, respectively) were decreased in plants grown in As-contaminated soils compared to lettuce plants grown in soils without the addition of As. However, NAC applications together with As stress increased these growth parameters. While the highest increase in shoot fresh and dry weight (58.31% and 37.85%, respectively) was observed in 250 µM NAC application, the highest increase in root fresh and dry weight (75.97% and 63.07%, respectively) was observed in 125 µM NAC application in plants grown in As-polluted soils. NAC application decreased the amount of ROS, MDA and H2O2 that increased with As stress, and decreased oxidative damage by regulating hormone levels, antioxidant and enzymes involved in nitrogen metabolism. According to gene expression profiles, LsHIPP28 and LsABC3 genes have shown important roles in reducing As toxicity in leaves. This study will provide insight for future studies on how NAC applications develop resistance to As stress in lettuce.

Evaluation of genetic diversity using iPBS-SCoT marker methods in native hawthorn genetic resources and species identification by using DNA barcoding method.

Hawthorn is an important medicinal plant that spreads around the world and is used in traditional Chinese medicine. Its flowers and leaves contain flavonoids, vitamins, organic acids and essential oils. Its fruit is consumed as fresh and dried and is an important plant for human health. In this study, iPBS (Inter Primer Binding Site) and SCoT (Start Codon Target Polymorphism) markers were used to analyze genetic variation among 101 hawthorn genotypes collected from Çoruh Valley, Türkiye and ITS markers were used for DNA barcoding.  Ten iPBS primers were used and a total of 400 alleles were identified from ten iPBS primers with an average of 40 alleles. PIC values ranged from 0.239 (iPBS 2387) to 0.272 (iPBS 2244). Twenty SCoT primers were used and have an average of 50.05 alleles. The PIC values of the primers ranged from 0.251 (SCoT 2) to 0.297 (SCoT 34). For the DNA barcoding study, it was confirmed that the correct region was amplified and sequenced. The genotypes we used in the study matched 14 different accession numbers by searching a BLASTN in the NCBI. NCBI similarity rates of hawthorn genotypes are between 90.83% and 100%. The study emphasizes the genetic diversity of hawthorn grown from seed and the importance of preserving plant genetic resources.

Characterization of Two-Component System gene (TCS) in melatonin-treated common bean under salt and drought stress.

The two-component system (TCS) generally consists of three elements, namely the histidine kinase (HK), response regulator (RR), and histidine phosphotransfer (HP) gene families. This study aimed to assess the expression of TCS genes in P. vulgaris leaf tissue under salt and drought stress and perform a genome-wide analysis of TCS gene family members using bioinformatics methods. This study identified 67 PvTCS genes, including 10 PvHP, 38 PvRR, and 19 PvHK, in the bean genome. PvHK2 had the maximum number of amino acids with 1261, whilst PvHP8 had the lowest number with 87. In addition, their theoretical isoelectric points were between 4.56 (PvHP8) and 9.15 (PvPRR10). The majority of PvTCS genes are unstable. Phylogenetic analysis of TCS genes in A. thaliana, G. max, and bean found that PvTCS genes had close phylogenetic relationships with the genes of other plants. Segmental and tandem duplicate gene pairs were detected among the TCS genes and TCS genes have been subjected to purifying selection pressure in the evolutionary process. Furthermore, the TCS gene family, which has an important role in abiotic stress and hormonal responses in plants, was characterized for the first time in beans, and its expression of TCS genes in bean leaves under salt and drought stress was established using RNAseq and qRT-PCR analyses. The findings of this study will aid future functional and genomic studies by providing essential information about the members of the TCS gene family in beans. Supplementary Information: The online version contains supplementary material available at 10.1007/s12298-023-01406-5.