## 4 Discussion  
### Chemical Composition and Yields of Essential Oils from P. rivinoides  
The plant organs that exhibited higher yields of EO were roots and leaves. This result was consistently observed in various plant families, including Piperaceae, Asteraceae, Lamiaceae, and Myrtaceae [39; 40; 41; 42]. Consequently, leaves and roots tend to contain a higher content of volatile compounds, compared to branches and stems [43]. In nature, plants face a wide range of biotic and abiotic factors, and this evolutionary pressure stimulates the development of adaptation mechanisms to the environment. In this context, EO production is a biological response resulting from complex and nuanced interactions between genotype and environment, involving changes in the expression of one or more genes in response to various environmental stimuli, such as UV radiation, temperature variations, microbial attacks, and herbivory, among others [44; 45; 46]. Plant leaves are particularly susceptible to these environmental stresses, as they play a fundamental role in photosynthesis and gas exchange processes. Therefore, they develop defense mechanisms against these stressors. Conversely, roots, responsible for water and nutrient absorption, maintain intimate contact with the soil and its microbiome, which include many pathogenic fungi and bacteria [47]. Consequently, these organs, compared to stems and branches, are subjected to a greater diversity of environmental stimuli. As a result, the production of high content of EO emerges as an adjustment between genotype, environment, and \begin{table}
\begin{tabular}{c c c} \hline \hline
**Sample Compared** & **Jaccard Index** & **Sorensen Index** \\ \hline roots \(\times\) steams & 5.77 & 10.91 \\ roots \(\times\) branches & 10.14 & 18.00 \\ roots \(\times\) leaves & 28.57 & 44.00 \\ steams \(\times\) branches & 6.00 & 12.00 \\ steams \(\times\) leaves & 4.00 & 7.00 \\ branches \(\times\) leaves & 31.00 & 20.50 \\ phase I \(\times\) phase II & 6.82 & 12.77 \\ phase I \(\times\) phase III & 3.85 & 7.00 \\ phase I \(\times\) phase IV & 18.33 & 31.00 \\ phase I \(\times\) phase V & 15.63 & 27.00 \\ phase II \(\times\) phase III & 36.00 & 52.00 \\ phase II \(\times\) phase IV & 24.00 & 38.00 \\ phase II \(\times\) phase IV & 21.00 & 35.00 \\ phase III \(\times\) phase IV & 25.00 & 40.00 \\ phase III \(\times\) phase V & 26.00 & 41.00 \\ phase IV \(\times\) phase V & 75.00 & 86.00 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Calculated values for assessing chemodiversity \(\beta\) for the composition of essential oils obtained from different organs and for ontogenetic phases of _P. rivinoides_. phenotypic expression, aiming to promote an increase in plant fitness, favoring survival and reproduction in challenging environments [3; 48]. Another important factor to consider in these variations is the anatomical structures that store EO, as well as the ease of extraction and the cellular organization of plant tissue. This includes elements such as the number, shape, size, distribution, location, and density of these structures [49]. For example, certain anatomical structures may provide greater accessibility to volatile compounds during the extraction process, such as oil glands present in leaves, which may be more readily exposed water vapor during extraction, resulting in a higher yield of EO. Additionally, leaf cells may be more prone to release EO due to their delicate cellular structure compared to stem or root cells, which may be denser and more resistant due to high lignification. Therefore, differences in plant anatomical structures may have a significant impact on the yield of extracted EO, both in terms of quantity and quality [50]. In the study of ontogeny, variations in the yields of EO do not allow us to make conclusive inferences due to the oscillation and lack of trend in the results. The absence of a pattern may be attributed to the existing natural variation in the plant.