Can chemopriming with silicon modulate primary and phenolic compounds metabolisms of Vigna unguiculata L seed embryo?

Agricultural production is currently facing numerous challenges, including climate change and soil degradation. These constraints directly compromise food security, particularly in vulnerable regions. In this context, seed priming appears to be a simple, effective, and inexpensive solution to improve agricultural performance. Among the most common types of priming is "chemopriming" which relies on the use of chemicals such as silicon. This mineral element, although not essential, is considered a stimulant. However, few studies have used silicon in chemopriming. Our work was in line with this perspective and aims to study the consequences of chemopriming V. unguiculata seeds with silicon in the form of SiO 2 (4 mM) on germination performance and metabolic and biochemical changes at the embryonic level. Silicon was applied using two distinct treatment modalities, either through simple seed imbibition in a SiO 2 solution or through chemopriming involving seed imbibition followed by drying. In parallel, hydropriming was performed using the same modalities to compare the specific effects of silicon with those of water alone. Our results showed that all pregermination treatments and particularly chemopriming improved the biometric aspects related to germination and emergence. Moreover, hydropriming and chemopriming in particular had a strong impact on the primary and secondary metabolism of these seed embryo axes. This impact was reflected through an activation of nitrate reductase mainly by chemopriming. However, a greater degradation of proteins and carbohydrate reserves was recorded for hydropriming unlike the treatment with silicon alone which seemed to inhibit this hydrolysis. We also noted that these pretreatments induced an increase in the content of proline, glycine betaine, auxins and phenolic compounds as well as an activation of the phenylalanine ammonia lyase (PAL). Our study also revealed that silicon penetrated into the seed embryo axes when the treatment with this mineral was applied. In light of these results, we can conclude that seed chemopriming with silicon was expected to play a crucial role in the transition to sustainable agriculture and a safer and healthier food future for future generations.