快速冷却过程中DTNB对含水甘蓝种子耐冻性的影响  

Effect of DTNB on Freezing Tolerance of Hydrated Brassica oleracea Seeds during Fast Cooling

作　　者：李良波 韩颖颖[1] 王秀丽 李维杰[1] 刘宝林[1] Li Liangbo;Han Yingying;Wang Xiuli;Li Weijie;Liu Baolin(Institute of Biothermal Science and Technology,School of Health Science and Engineering,University of Shanghai for Science and Technology,Shanghai,200093,China)

机构地区：[1]上海理工大学健康科学与工程学院系统生物热科学研究所,上海200093

出　　处：《制冷学报》2024年第5期159-166,共8页Journal of Refrigeration

摘　　要：种子水分含量是影响种子低温保存的重要因素,已有的研究表明种子球蛋白降解可以提高含水种子的低温耐冻能力。选取甘蓝种子为实验材料,通过外源添加2-硝基苯甲酸[5,5′-dithiobis-(2-nitrobenzoic acid),DTNB]对种子吸胀处理后进行快速降温(降温速率为-1℃/min),研究DTNB对含水甘蓝种子耐冻性的影响。结果表明:DTNB显著提高了快速降温后甘蓝种子的发芽率;推迟了胚内冰晶形成的起始温度(对照组vs DTNB组:-14.78℃vs-16.43℃)。双向电泳表明与对照组相比在25 kDa以下位置积累了2个差异蛋白点,质谱鉴定为12 s储存球蛋白;检测到球蛋白及其水解多肽巯基含量显著提高,非酶促氧化剂AsA和GSH与对照组相比分别提高1.26倍和1.22倍;DTNB还促进了冷胁迫诱导基因ICE1和CBF的表达。综上所述,DTNB可在快速降温条件下调控含水种子的分子生理活性变化,进而提高种子抗冻性。The moisture content of seeds poses a significant challenge in their cryopreservation.Previous studies have shown that the hydrolysis of seed globulins can improve the freezing resistance of hydrated seeds.In this study,Brassica seeds were selected as the experimental material,and the effect of 5,5′-dithiobis-(2-nitrobenzoic acid)(DTNB)on the freezing tolerance of hydrated Brassica seeds was investigated under the cooling rate of-1℃/min.The results showed that DTNB significantly improved the germination rate of Brassica seeds after rapid cooling.The initial temperature of ice crystal formation in seeds was delayed in DTNB treatment(control group vs.DTNB group:-14.78℃vs.-16.43℃).Compared with the control,two different protein spots accumulated below 25 kDa;which were identified as 12 s storage globulins by mass spectrometry.The sulfhydryl group content,globulin,and its hydrolyzed polypeptide were significantly increased in the DTNB treatment.The non-enzymatic oxidants AsA and GSH increased by 1.26 times and 1.22 times,respectively,relative to the control.DTNB also promoted the expression of cold stress-responsive genes,including ICE1 and CBF.In conclusion,DTNB can improve the freezing tolerance of Brassica seeds after rapid cooling through molecular and physiological regulation.

关 键 词：快速冷却 甘蓝种子 2-硝基苯甲酸 球蛋白 水解 

分 类 号：Q945.78[生物学—植物学] TS205.7[轻工技术与工程—食品科学]