SOUTHERN JOURNAL OF SCIENCES

Sugar beet is a crop able to resist high levels of soil salinity after emergence and establishment. Considering the significant difference in the effect of nitrogen forms on sugar beet performance under normal conditions, the form of nitrogen may affect the performance of sugar beet plants under abiotic stress, particularly salinity. Additionally, exploring the most appropriate type of nitrogen for sugar beet could mean optimizing sucrose content. Therefore, here using two lines, sugar beet was grown in pots (filled with 4 kg soil), salt-resistance (line 7233- p.29 x Mst), and salt-sensitive (line 3929-21939), the effect of two different forms of nitrate in the form of calcium nitrate (1 g per pot) and ammonium in the form of ammonium sulfate (1 g per pot) under normal and salt stress condition (40 Millimoles per liter sodium chloride) were evaluated. The result revealed the positive influence of nitrate over ammonium by indicating higher dry weight in both sensitive line: 19.2 and 13.6 g, and tolerance line: 20.4 and 13.6 g, respectively alone and in combination with salinity stress. Similarly, root yield levels positively influenced by nitrate treatment either alone or under salinity stress (sensitive line: 194.5 and 243.2 g and tolerance line: 207 and 249.5 g). The outcomes additionally showed the accumulation of proline aerial parts in both lines, and however, the proline accumulation of sensitive line was higher (3.9 mg/g dry weight). Moreover, induction of proline aggregation was considerably higher in nitrate nitrogen-treated sensitive line (9.3 mg/g dry weight). The absence of significant difference was obseved between nitrogen treatments in terms of extractable sucrose and root molasses sugar. Also, the root impurities increased in those treated with nitrate-nitrogen and salinity. It can be concluded that nitrate-nitrogen has improved the performance of both sugar beet lines against salinity stress, and its practical application is adviseable.

Background: Antibiotic resistance is currently one of the biggest problems in public health. Infectious diseases are the second human death cause, and the emergence of antimicrobial-resistant bacteria increases mortality and morbidity rates. There is a growing clinical need for the development of new antibiotics. In this line, WHO issued an alert about 12 bacteria with an urgent need to develop new antibiotics. Aims: This review aims to analyze the current knowledge of their antibacterial activity against the gram-positive pathogens listed by WHO and their extraction techniques. Methods: We systematically reviewed the literature in PubMed, searching publications describing the use of natural extracts as antibiotics over bacteria. The exclusion criteria consisted of limiting papers on natural extracts tested over the bacteria culture related to eleven selected bacteria, according to an alert issued by WHO in 2017, and seven plant extracts. Results: All the gram-positive bacteria present in the WHO alert have been treated, with different degrees of advance, with some of the plant extracts and plant-based compounds reviewed. Currently, they are in the preclinical stage. Edible herbs are more often used, as well as artemisia and wine byproducts. Discussion: Natural products based on plants have shown to be efficient in inhibiting bacterial growth, even in antibiotic-resistant strains. The classical extraction methods are still in use and have been improved with the available technology to improve efficiency and yield. Conclusions: Ongoing evidence shows that plant extracts and plant-based compounds are effective as antibacterial, with minimal effects on the host cell, a promising antibiotic source. Furthermore, they are sustainable, environmentally friendly, and renewable.

In many low-temperature areas, the environmental factor is an important limiting factor for the production and distribution of horticultural plants. This study aimed to investigate the cold tolerance of the male catkins and inoculated female flowers to screen the popular native hazelnut cultivars in Qazvin under low-temperature stress. A completely randomized factorial block design with three replications was used in this experiment with eight cultivars (Nakhnroud, Khandan, Mish-Pestan, South of Qarabagh, Asl-e-Qarabagh, Rasmi, and Gerdashkevar). After removing each of the treated samples at the end of the experiment, the samples were examined morphologically (appearance) and compared with the control. The changes were recorded as qualitative traits. To understand the influence of cold stress on reproductive organs, hydrogen peroxide and proline were measured. The results showed the onset of freezing in unopened male catkins at -7 and -9 °C and in inoculated female flowers at -3 °C. Damage to unopened male catkins' tissue occurred at -11 °C and in female flowers at -5 °C. The highest value observed among cultivars in the case for proline content of male catkins was in Mish-Pestan and Khandan cultivars with 0.816 and 0.660 µmol/ g FW, respectively. In inoculated female flowers, Mish-Pestan and Tabestaneh cultivars with 0.185 and 0.168 µmol/ g FW, respectively, showed the highest statistically significantincrease in proline content. Interestingly, the cultivars with the highest proline content in male catkins indicated the most increase in H2O2; Mish-Pestan and Khnadan with 0.569 and 0.541 ug/g FW, respectively. Asl-eQarabagh was observed to have the least H2O2 content (0.042 ug/g FW) among cultivars. Again, in inoculated female flowers, those with the highest concentration of proline (Mish-Pestan and Tabestaneh) were found to have the highest H2O2 content (0.335 and 0.331 ug/g FW, respectively