Flesh softening is closely related to the quality of postharvest produces. Although the use of calcium chloride (CaCl) has been shown to inhibit fruit softening, the underlying molecular mechanisms have remained unclear. In our present investigation, CaCl treatment resulted in an enhancement of cytosolic free Ca and polysaccharide contents, firmness, and the integrity of the cell wall structure, particularly evident in the denser middle lamella of fresh-cut cantaloupe. CaCl treatment also inhibited the cell wall degrading enzyme activities and gene expressions. Moreover, CmCAMTA2 could identify and bind to the CG-box structure of , , and , thereby suppressing their transcription. In conclusion, current findings illustrated that CaCl treatment triggered CmCAMTA2-mediated transcriptional suppression on cell wall degrading genes, inhibited the polysaccharide component degradation, and maintained better structure integrity of the cell wall, thereby delaying the flesh softening of fresh-cut cantaloupe.

中文翻译：

---

外源CaCl2通过抑制鲜切哈密瓜细胞壁降解延缓果肉软化

果肉软化与采后产品的品质密切相关。尽管氯化钙 (CaCl) 的使用已被证明可以抑制果实软化，但其潜在的分子机制仍不清楚。在我们目前的研究中，CaCl 处理导致胞质游离 Ca 和多糖含量、硬度和细胞壁结构完整性的增强，在鲜切哈密瓜较致密的中间层中尤其明显。 CaCl处理还抑制细胞壁降解酶活性和基因表达。此外，CmCAMTA2 可以识别并结合 、 和 的 CG-box 结构，从而抑制它们的转录。总之，目前的研究结果表明，CaCl处理触发了CmCAMTA2介导的细胞壁降解基因的转录抑制，抑制了多糖成分的降解，并保持了更好的细胞壁结构完整性，从而延缓了鲜切哈密瓜的果肉软化。