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Approaches to Enhance Antioxidant Defense in Plants
Published in Hasanuzzaman Mirza, Nahar Kamrun, Fujita Masayuki, Oku Hirosuke, Tofazzal M. Islam, Approaches for Enhancing Abiotic Stress Tolerance in Plants, 2019
Hamid Mohammadi, Saeid Hazrati, Mohsen Janmohammadi
Genes encoding pyrroline-5-carboxylate synthetase (P5CS) and pyrroline-5-carboxylate reductase (P5CR) are the main target points for manipulating the proline biosynthesis, and their overexpression has often been accompanied by an increased tolerance to environmental stress and improvements of redox balance (Verslues and Sharma, 2010). Besides, it has demonstrated that polyamines function in stress tolerance largely by modulating the homeostasis of ROS due to their direct, or indirect, roles in regulating antioxidant systems or suppressing ROS production (Liu et al., 2015). There are three major polyamines in plants, putrescine, spermidine, and spermine. It has been revealed that genes encoding arginine decarboxylase play a critical role in the production of putrescine in Arabidopsis thaliana. Putrescine is then converted into spermidine by spermidine synthase, and spermidine is then converted into spermine by spermine synthase. Polyamines synthesis may vary between tissues/organs, and depending on the type of polyamine, the rate-limiting enzyme will be different.
Recognition of the prioritized types and individual of pharmaceuticals and personal care products (PPCPs) in the drinking water of Shanghai and a health risk assessment
Published in Human and Ecological Risk Assessment: An International Journal, 2019
Guoqiang Gu, Haowen Yin, Qing Zhu, Lu Shen, Kun Zhang, Min Liu, Qiang Wu
Dicyclohexylamine inhibits spermidine synthase (Pegg and Mccann 1982) and is used in animal and bacterial systems (Hibasami et al. 1980). Dicyclohexylamine was detected in all samples at concentrations ranging from 0.11 ng/L to 11.8 ng/L, with an average concentration of 4.7 ng/L. This value was the highest detected concentration of all the PPCPs examined, as shown in Table 1. Although the enzyme inhibitor only contains one analyte, it had the highest concentration and detection frequency (Figure 3). It was also determined that dicyclohexylamine was the main component in all samples, as shown in Figure 4. The proportion of dicyclohexylamine was higher than 50% in 16 of 35 samples, and it had a maximum value of 86.3%. As a result, the compound accounted for nearly 50% of all detected PPCPs, as shown in Figure 5. Dicyclohexylamine is used as both an enzyme inhibitor and an important initiator in chemical synthesis (Han et al. 2013). Additionally, one of the most important uses of dicyclohexylamine is as a vapor-phase corrosion inhibitor (Fazullin et al. 2017). The prominence of dicyclohexylamine in pollution may result from these extensive and varied methods of industrial emission.