Transcriptomic analysis of the mechanisms underlying delayed quality deterioration in fresh-cut asparagus lettuce using ascorbic acid and L-cysteine in a sodium carboxymethyl cellulose coating
The deterioration in the quality of fresh-cut asparagus lettuce (Lactuca sativa var. angustata) during storage can be significantly delayed by immersing it in a solution containing 0.67 % sodium carboxymethyl cellulose (CMC-Na), 0.38 % ascorbic acid (AsA), and 0.85 % L-cysteine (L-Cys), resulting in improved color and texture maintenance, as well as an extended shelf life. The mechanism underlying the delay in deterioration of fresh-cut asparagus lettuce by the solution was elucidated through transcriptomic analysis. This demonstrated that the accelerated deterioration of fresh-cut asparagus lettuce was primarily attributed to enhanced respiration and transpiration after mechanical injury, along with increased susceptibility to microbial infection. In comparison to a control group, treatment with the solution effectively attenuated the upregulation of the LsACO3 and LsACS1 genes; it downregulated the expression of the phospholipase-related genes LsNPC6, LsPLC2, and At2g42690. Conversely, there was substantial upregulation of gene expression related to L. sativa calmodulin-like proteins and L. sativa calcium-dependent protein kinases, along with activation of the MAPK signaling pathway and significant upregulation of genes associated with L. sativa ethylene-responsive transcription factors involved in the defense response. These results indicate that treatment with the solution effectively delays the deterioration of fresh-cut asparagus lettuce during storage by inhibiting endogenous ethylene synthesis, mitigating reactive oxygen damage, and enhancing disease resistance, thereby providing superior preservation of its color and texture.