Effect of calcium chloride (CaCl₂) on γ-aminobutyric acid (GABA) accumulation pathways in fresh-cut pears was investigated. The metabolites, enzyme activity and gene expression associated with GABA shunt and polyamine degradation were measured. Results demonstrated that CaCl₂ treatment promoted GABA accumulation and reduced the glutamate (Glu) content in fresh-cut pears. Ca²⁺ fluorescence in pear cell, glutamate decarboxylase (GAD) activity and its gene expression increased significantly under CaCl₂ treatment correspondingly. Meanwhile, the Ca²⁺ channel blockers lanthanum chloride (LaCl₃) treatment not only significantly inhibited the activities of GAD, GABA transaminase (GABA-T), diamine oxidase (DAO), polyamine oxidase (PAO) and aminoaldehyde dehydrogenase (AMADH), but also down-regulated the transcripts of PbGAD, PbGABA-T, PbPAO1 and PbPAO2. Taken together, it can be concluded that CaCl₂ seems to be more effective to GABA shunt, while LaCl₃ treatment mightily stimulate GABA shunt and polyamine degradation pathway.

研究了氯化钙（CaCl ₂）对鲜切梨中γ-氨基丁酸（GABA）积累途径的影响。测量了与GABA分流和多胺降解相关的代谢物，酶活性和基因表达。结果表明，CaCl ₂处理促进了鲜切梨中GABA的积累并降低了谷氨酸（Glu）含量。在CaCl ₂处理下，梨细胞Ca ²⁺荧光，谷氨酸脱羧酶（GAD）活性及其基因表达显着增加。同时，Ca ²⁺通道阻滞剂氯化镧（LaCl ₃）处理不仅显着抑制GAD，GABA转氨酶（GABA-T），二胺氧化酶（DAO），多胺氧化酶（PAO）和氨基醛脱氢酶（AMADH）的活性，而且下调PbGAD，PbGABA-T的转录本，PbPAO1和PbPAO2。两者合计，可以得出结论，CaCl ₂似乎对GABA分流更有效，而LaCl ₃处理可能刺激GABA分流和多胺降解途径。