The Phyllanthus genus exhibits a broad distribution spanning across the majority of tropical and subtropical regions. Due to their ability to synthesize medicinal bioactive compounds such as lignans, they have been utilized historically in traditional medicine to treat a wide range of ailments. This review discusses the current knowledge on the potency of lignans for medicinal purposes, the benefit of lignans for plants, various lignans produced by Phyllanthus, and how lignan synthesis could be increased through biotic and abiotic elicitation. Finally, we present a set of connected hypotheses to explain how signaling crosstalk between endophytic microbes and drought stress responses regulates lignan production. Although the mechanisms of lignan synthesis in Phyllanthus are not fully explored, this review strongly supports the view that endophytic fungi and drought stress can increase lignan production in plants belonging to the genus Phyllanthus. The medicinal plant–endophyte–drought stress relationship helps to improve the lignan yield of Phyllanthus, which is crucial for human health and can be optimized under in vitro and in vivo conditions.

Plant-specialized metabolites are unique sources for pharmaceuticals and industrially valuable biochemicals. Accumulation of these metabolites is common in plants stimulated by biotic or abiotic stressors and/or elicitors. One of the abiotic factors that influence the plant’s bioactive molecule is drought stress, which can be employed to stimulate the production of bioactive compounds in plants. Phyllanthus niruri is commonly used as a medicinal plant in many parts of the world for the treatment of various diseases because it contains bioactive compounds that have the potential to be antioxidants, antimicrobials, and anti-hepatoprotective. Our previous studies have demonstrated that drought stress up to 70% field capacity (FC) could increase crop production as well as phenol and flavonoid contents. This study aimed to analyze the metabolite profile of P. niruri, which was subjected to drought stress for various FC (Control, 85%, 80%, 75%, 70%, 55%). Using chromatography-mass spectrophotometry (GC-MS) analysis, forty-seven compounds were identified. Three compounds were detected in control and all treatments, whereas four compounds were only detected in drought-stressed plants. β-sitosterol, 9-tricosane, heneicosane, and hexacosane are the main compounds only detected at 80% FC. The clustering analysis revealed that drought stress induced distinct compounds compared to control. Moreover, 85% -75% FC presumably induces similar compounds as they were in the same cluster, while plants responded differently upon 70% FC and 55% FC. In conclusion, P. niruri synthesizes different bioactive compounds under different drought-stress conditions.

Drought stress is one of the most significant abiotic factors that limit plant growth and survival. However, drought stress treatment can increase the synthesis of plant bioactive compounds, especially in medicinal plants like Phyllanthus niruri. The research aim was to assess the effects of drought stress on the growth response, phenolics, and flavonoid content of P. niruri. P. niruri was subjected to drought stress for various field capacities (FC) (Control, 85%, 80%, 75%, 70%, 55%). The result showed that all observed variables are significantly different, while chlorophyll content is not entirely different. Proline content increased by 85%FC but decreased by 80%FC. The highest total fresh weight and total dry weight were shown at 85%FC but were not significantly different from 80%FC to 70%FC. These findings demonstrate that P. niruri can survive by maintaining biomass weight even after exposure to 70% FC. 80%FC treatments showed higher total flavonoids, phenols, and yield than other treatments and controls. Entire flavonoid content strongly correlated with total phenol content, with a correlation value of 0.93. The chlorophyll content is also strongly associated with total flavonoid and phenol content of 0.51 and 0.68, respectively. Proline content is negatively correlated with total flavonoid and phenol content, indicating that higher exposure to drought stress is expected to reduce the accumulation of flavonoids and phenols. Principal component analysis (PCA) revealed that 80% FC and 70% FC treatment are expected to increase yield, total flavonoid, and phenol content. Thus, it must be optimized for further research.

This research is an initial study of the effects of vernalization and Gibberellins in two different environments. The research was conducted in a split-split plot design with three factors and three times repetition. The main plot was the environment (environment 1, environment 2), the split plot was vernalization temperature (3±2 and 9±2°C), and split-split plot was Gibberellin concentration (0, 50, 100, 150 ppm). The result showed that the vernalizations and Gibberellin have significantly affected plant height (p<0.01). The environment significantly affected plant height, number of tillers, and number of leaves. There was an interaction between Gibberellin and environment treatment on plant height and an interaction between vernalization, Gibberellin, and environment on the number of leaves. The environment with temperature: 29±2.18°C, RH: 45±9.14%, light intensity: 9272±7669 μmol m^-2 S^-1 showed plant height and the number of tillers higher than other environments, contrary to the number of leaves. According to the principal component analysis, this environment is more suitable for all vernalization and Gibberellin treatments than other environments. The results of this study indicate that the environment more influences vegetative growth than the other two treatments.