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Plants often face incompatible growing environments like drought, salinity, cold, frost, and elevated temperatures that affect plant growth and development leading to low yield and, in worse circumstances, plant death. The arsenal of versatile compounds for plant consumption and structure is called metabolites, which allows them to develop strategies to stop enemies, fight pathogens, replace their competitors and go beyond environmental restraints. These elements are formed under particular abiotic stresses like flooding, heat, drought, cold, etc., and biotic stress such as a pathogenic attack, thus associated with survival strategy of plants. Stress responses of plants are vigorous and include multifaceted crosstalk between different levels of regulation, including regulation of metabolism and expression of genes for morphological and physiological adaptation. To date, many of these compounds and their biosynthetic pathways have been found in the plant kingdom. Metabolites like amino acids, phenolics, hormones, polyamines, compatible solutes, antioxidants, pathogen related proteins (PR proteins), etc. are crucial for growth, stress tolerance, and plant defense. This review focuses on promising metabolites involved in stress tolerance under severe conditions and events signaling the mediation of stress-induced metabolic changes are presented.

Preliminary phytochemical, pharmacological, antibacterial and antiovulatory studies were conducted on the seeds of Annona squamosa, Linn. Qualitative analysis revealed the presence of alkaloids, reducing sugars, glycosides and steroids and the absence o f saponins, resins, tannins and volatile oils. Ethanofic extract exhibited no pharmacological, anti-bacterial or antiovtrlatory activities o f therapeutic significance.Annona squamosa Linn. (SHARIFA) is reputed to possess varied medicinal properties (KHAN, 1911;KIRTIKAR and BASU, 1935, CHOPRA et al., 1958). Though the claims of its use as an insecticidal agent have been investigated by many workers, (CHEEMA et al., 1958; MUKERJEE and RAMGOVIND, 1958;VISWESWARIAH et al., 1971), work with respect to its other alleged pharmacological properties is lacking. This communication embodies a preliminary report on phytochemical, pharmacological, antibacterial and antiovulatory studies carried out with the total extract of seeds. Material and MethodsAuthenticated samples of the dried seeds were obtained from Hamdard (waqf) Laboratories, Delhi. These were successively extracted with petroleum ether, 90% ethanol and distilled water and percentage extractibilities determined. Qualitative analysis was done for the presence of alkaloids, reducing sugars, glycosides, tannins, resins, saponins, volatile oils and steroids.Pharmacological and antibacterial studies were carried out with the ethanolic extrtct. The parameters used for pharmacological investigations were blood pressure, respiration, ECG (Lead 11) and heart in situ of anaesthetised cats, isolated tissue preparations e. g. perfused frog heart, rabbit jejunum, rat uterus and frog rectus abdominis muscle. For antibacterial studies, in vitro filter paper disc method (CRUICKSHANK, 1965) was employed against five gram positive (Staphylococcus atrreus, Streptococcus pyogenes, Streptococcus uiridans, Diplococcus pneumoniae and Corynebacterium diphtheriae) and five gram negative (Eschrichia coli. Salmonella typhi, Salmonella pnratyphi-A, Salmonella, partyphi-B, and Shigella flexneri) organisms.

Plant tissue culture technique employed for the identification and isolation of bioactive phytocompounds has numerous industrial applications. It provides potential benefits for different industries which include food, pharmaceutical and cosmetics. Various agronomic crops i.e., cereals, fruits, vegetables, ornamental plants and forest trees are currently being used for in vitro propagation. Plant tissue culture coupled with biotechnological approaches leads towards sustainable agricultural development providing solutions to major food security issues. Plants are the rich source of phytochemicals with medicinal properties rendering them useful for the industrial production of pharmaceuticals and nutraceuticals. Furthermore, there are numerous plant compounds with application in the cosmetics industry. In addition to having moisturizing, anti‐ageing, anti‐wrinkle effects; plant-derived compounds also possess pharmacological properties such as antiviral, antimicrobial, antifungal, anticancer, antioxidant, anti-inflammatory, and anti-allergy characteristics. The in vitro propagation of industrially significant flora is gaining attention because of its several advantages over conventional plant propagation methods. One of the major advantages of this technique is the quick availability of food throughout the year, irrespective of the growing season, thus opening new opportunities to the producers and farmers. The sterile or endangered flora can also be conserved by plant micro propagation methods. Hence, plant tissue culture is an extremely efficient and cost-effective technique for biosynthetic studies and bio-production, biotransformation, or bioconversion of plant-derived compounds. However, there are certain limitations of in-vitro plant regeneration system including difficulties with continuous operation, product removal, and aseptic conditions. For sustainable industrial applications of in-vitro regenerated plants on a large scale, these constraints need to be addressed in future studies.

Mango sudden death (MSD) or quick decline (QD) is the most destructive disease found in mango orchards of Pakistan and is characterized by collapse of the vascular system by Ceratocystis fimbriata and Lasiodiplodia theobromae. Cultural practices, chemicals, and biological control are the most valuable tools for the management of MSD, but the role of micronutrient deficiencies has remained an area that is heavily ignored by the farming community. To study the impact of micronutrients, four mango orchards were selected at different locations where different combinations of micronutrients, i.e., Zinc (Zn), Boran (B), and Copper (Cu) in the form of Zinc sulphate (ZnSO4), Borax/Boric acid (H3BO3), and Copper Sulphate (CuSO4), were applied both foliar and in drench along with the recommended doses of Nitrogen: Phosphorous: Potassium (NPK), and Farmyard manure (FYM), respectively. The quantities of micronutrients were determined from the soil and leaves before and after application of the treatments. The impact of micronutrients was measured in terms of reduction in disease severity and increase in fruit yield. The results revealed that the application of all three micronutrients both in soil drench and in foliar form significantly decreased the disease severity at three locations and increased the yield in all four mango orchards. Application of ZnSO4 (0.8%), +H3BO3 (0.8%), +CuSO4 (0.5%) and as soil drench ZnSO4 (400 g) + Borax (200 g) + CuSO4 200 g plant−1 proved to be the best treatments, with an average of 12.88 and 14.03% reduction in disease severity and with an average yield of 128 and 119 kg, respectively. The application of micronutrients would be a promising solution in an integrated disease management program used to tackle MSD.