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Melissa officinalis is a perennial herbaceous plant from Lamiaceae family, widely used in food and pharmaceutical industries to add aroma. Drought stress in plants may happen due to the increase in water loss, insufficient water absorption or both. Salicylic acid (SA) is an important secondary metabolite in plants with hormone-like action in some biochemical pathways. Adding it during water-deficit stress, may alter a number of physiological processes, increasing the resistance of plant against possible damage by water loss. The aim of this study was to examine the effect of drought stress (DRU) on secondary metabolites of Melissa officinalis and also the efficacy of salicylic acid treatment to minimize the damages. According to the results, treatment of plant with 0.7 mM salicylic acid had considerable alteration in the quantity of important secondary metabolites. Protein concentration increased in all stages; Chlorophyll a reached to the highest amount; the amount of the MDA increased at the first and second stages in 1/3 fc drought treatment as well as at the third stage in 2/3 fc. Besides, total phenol content increased at stage I in 1/3 fc drought and the flavonoid content increased in 1/3 fc drought at all stages. Finally, content of anthocyanin was increased at first and third stages 1/3 fc drought, as well as at second stage in 1/3 fc drought. In conclusion, application of salicylic acid (0.7 mM) was useful for improving quality of lemon balm subjected to stress due to water deficit.

HIV infection is one of the most serious causes of death throughout the world. CD4+ T cells which play an important role in immune protection, are the primary targets for HIV infection. The hallmark of HIV infection is the progressive loss in population of CD4+ T cells. However, the pathway causing this slow T cell decline is poorly understood [16]. This paper studies a discontinuous mathematical model for HIV-1 infection, to investigate the effect of pyroptosis on the disease. For this purpose, we use the theory of discontinuous dynamical systems. In this way, we can better analyze the dynamical behavior of the HIV-1 system. Especially, considering the dynamics of the system on its discontinuity boundary enables us to obtain more comprehensive results rather than the previous researches. A stability region for the system, corresponding to its equilibria on the discontinuity boundary, will be determined. In such a parametric region, the trajectories of the system will be trapped on the discontinuity manifold forever. It is also shown that in the obtained stability region, the disease can lead to a steady state in which the population of uninfected T cells and viruses will preserve at a constant level of cytokines. This means that the pyroptosis will be restricted and the disease cannot progress for a long time. Some numerical simulations based on clinical and experimental data are given which are in good agreement with our theoretical results. [ABSTRACT FROM AUTHOR]