## 3 Discussion
While cellulases and PGs primarily degrade cell wall polysaccharides, expansins loosen the cell wall structure, and cellulose syntheses contribute to remodeling cellulose, maintaining or subtly altering the cell wall's integrity. Understanding the interplay and regulation of these enzymes is essential for controlling fruit softening, texture development, and overall fruit quality. By manipulating the expression of the genes encoding these enzymes, breeders can develop tomato varieties with improved firmness, an extended shelf life, and tailored processing qualities. In plants, ascorbate plays a crucial role in various physiological processes, including photosynthesis, cell growth, hormone signaling, enzyme cofactor activity, flowering, and stress responses [27; 28]. It is a critical component of the ascorbate-glutathione cycle, which efficiently detoxifies the reactive oxygen species (ROS) generated during normal metabolic processes. Tomatoes are a significant source of ascorbate in the human diet, and understanding the metabolism in tomatoes can provide insights into improving their content in food crops. Ascorbate metabolism involves several enzymatic and non-enzymatic reactions, and the differential expression of genes encoding these enzymes can affect the ascorbate content in plants. The differential expression of the genes involved in ascorbate metabolism between the M7_5 and M29_2 tomato fruits suggests that these genes could contribute to their different ascorbate contents. The upregulation of _GDP-L-galactose phosphorylase_ (_Solyc06g073320.3_) in M7_5 could increase the synthesis of ascorbate precursors, while the upregulation of _monodehydroascorbate reductase 1_ (_Solyc09g009390.3_) could enhance the regeneration of ascorbate from its oxidized forms. On the other hand, the downregulation of _aldehyde dehydrogenase_ (_Solyc06g06260.3_ and _Solyc01g011510.3_) and _peroxidase_ (_Solyc04g074640.3_ and _Solyc11g018550.3_) in M7_5 could reduce the oxidative degradation of ascorbate and the consumption of its reduced form. Disrupting _L1L4_ resulted in tomato fruit with a significantly altered expression of genes involved in fatty acid biosynthesis and degradation. This may lead to decreased fatty acid activation and modification, potentially enhanced unsaturated fatty acid synthesis, and reduced \(\beta\)-oxidation. The latter could diminish energy production, alter precursor availability for volatile compound biosynthesis, and shift lipid metabolism. Upregulation of specific _ADH_ genes and _Cytochrome P450 86A1_ may represent compensatory mechanisms or shifts in metabolic flux, influencing volatile compound production and potentially modifying the fruit's cuticular wax composition. The two _ll14_ disruption lines show varying gene expression patterns, which is likely due to the pleiotropic functions of _L1L4_. This finding is consistent with the established role of LEC1 and LEC1-like genes as critical regulators of fatty acid biosynthetic genes in _Arabidopsis_[29]. Similarly, in soybean, _GmLEC1_ activates the genes involved in fatty acid biosynthesis while simultaneously repressing the transcription factors (e.g., GL2, MUM4, MYB5, and TT2) that negatively regulate lipid biosynthesis [30].