## 4 Discussion
Pyrophosphates, a class of enzymes, play a vital role in catalyzing the degradation of pyrophosphate. This enzymatic process provides plants with essential energy, particularly in low-oxygen conditions when ATP synthesis is not feasible [46]. The data exhibited a decrease in the expression of genes linked to \"cellular response to stress\", and \"pyrophosphate activity\" as the levels of P fertilization increased. This observation implies that lower P levels may serve as a stressor, leading to the activation of stress-related genes. The term \"GTP binding\" (GO:0005525) is also pertinent to signaling, as GTP-binding proteins, particularly the Rop GTPase family, participate in the regulation of numerous biological processes by utilizing an on/off mechanism. These processes include signal transduction, cell polarity, cell shape, hormone responses and pathogen defense [47]. The terms \"methylation\" (GO:0032259) and \"methyltransferasearse activity\" (GO:0008168) are linked to the regulation of gene activity while \"phosphorylation\" (GO:0016310) is connected to the regulation of protein activity. Notably, DNA methylation, an epigenetic mechanism mediated by methyltransferases, plays a pivotal role in controlling gene expression, thereby influencing processes related to growth, development and stress tolerance in plants [48]. In accordance with the study of [PERSON] et al., where it was observed that in soybean that low P conditions increased the level of DNA methylation [49], the results showed that the expression levels of genes that belong to the \"methyltransferasearse activity\" function decreased in higher P treatments. An elevated expression of these genes under low phosphorus (P) conditions may indicate increased methylation levels, which are associated with broader gene regulatory processes. Over the past decade, the concept of \"epitranscriptomics\" has gained prominence, drawing significant attention from the scientific community. Researchers have increasingly focused on post-translational modifications of RNA, particularly RNA methyl modifications, which exhibit a strong correlation with plant survival and fitness [50]. Meanwhile, phosphorylation serves as a fundamental reversible mechanism for posttranslational modifications that govern protein activity and its interactions with other molecules. This biological process is mediated by kinases that introduce phosphate groups to proteins, while phosphatases control dephosphorylation by removing these phosphate groups. This reversible system functions as a signal transduction mechanism and has been conclusively demonstrated to hold significant importance in the regulation of phytohormones and the enhancement of cold stress tolerance [51]. Through the analysis, several genes have been uncovered and identified that are associated with GO terms such as \"GTPase activity\" (GO:0003924), \"small GTPase regulator activity\" (GO:0005083), \"methyltransferasearse activity\" (GO:0008168), \"heat shock protein binding\" (GO:0031072), \"pyrophosphatase activity\" (GO:0016462), \"kinase activity\" (GO:0016301) and \"phosphatase activity\" (GO:0016791). In the current context of climate change, genes linked to stress signaling and stress tolerance, and in this case genes whose expression correlates with the extent of P fertilization, hold significant potential as promising candidates for further investigation. Such research endeavors may yield valuable outcomes that can be applied to breeding programs and the development of effective cultivation techniques. Moreover, P fertilization seems to affect the seed coat properties, without causing any anatomic alterations in the seed [52]. One of the most decisive traits for the market value of lentils is their seeds' physical properties. Seed coat hardness is considered a limiting factor for farmers and consumers. Hardness is attributed to the pigment and, mainly, tannin (proanthocyanidins) accumulation that happens from the embryo development in the seed right after fertilization [53].