摘要
研究不同浓度钙(0、1和10 mmo1/L CaCl2;5 mmo1/L EGTA)对苹果果实钙调蛋白(CaM)含量和Ca2+-AT-Pase活性及其基因表达的影响。利用同源克隆方法分离CaM和Ca2+-ATPase基因,采用荧光定量PCR方法研究它们表达特征。结果表明,果实切片外源补钙,可溶性Ca2+及CaM含量在高钙处理12 h达到高峰;高钙处理12 h质膜Ca2+-ATPase活性显著增加,与胞内CaM含量增加时间一致;高钙处理24 h液泡膜Ca2+-ATPase活性显著增加;随着质膜和液泡膜Ca2+-ATPase活性显著增加,可溶性Ca2+含量在加钙处理48 h显著下降。研究基因表达发现,加钙处理6 h苹果CaM基因的表达量显著增加;加钙处理12 h苹果Ca2+-ATPase基因的表达量显著增加,与CaM含量及质膜Ca2+-ATPase活性变化一致。果实缺钙处理显著增加CaM基因表达量,而苹果Ca2+-ATPase基因的表达量没有显著变化。上述研究表明,苹果补钙可以提高细胞内可溶性Ca2+和CaM含量以及CaM基因的表达量,有效启动钙信使系统;质膜及液泡膜Ca2+-ATPase是调控胞内Ca2+关键的酶,通过提高质膜及液泡膜Ca2+-ATPase的活性及Ca2+-ATPase基因的表达量,维持胞内Ca2+的稳态水平。
Effects of calcium on calmodulin（CaM） content,Ca2＋-ATPase activity and their gene expressions in apple（Malus pumila） fruits were investigated under the hydroponic condition with 0,1,10 mmo1/L CaCl2 and 5 mmo1/L EGTA.CaM and Ca2＋-ATPase gene were isolated by homologous cloning and their expression patterns were analyzed by real-time PCR.Addition of 10 mmo1/L CaCl2 to the culture solutions with 12 h exposure significantly increased soluble Ca2＋ and CaM contents in apple fruits.With the CaM content increasing,plasma and tonoplast membrane Ca2＋-ATPase activities were enhanced after 12 and 24 h Ca exposure respectively,resulting in the decrease in the soluble Ca2＋ content after 48 h Ca exposure.In molecular level,the abundances of CaM and Ca2＋-ATPase genes were up-regulated after 6 h and 12 h Ca exposure,respectively,in accordance with change of the CaM content and plasma membrane Ca2＋-ATPase activity.Addition of 5 mmo1/L EGTA to the culture solutions induced up-regulated the expression of the CaM gene,however,did not markedly change the expression of the Ca2＋-ATPase gene.It was concluded that external calcium might increase soluble Ca2＋ and CaM contents and the expression of the CaM gene to stimulate an intracellular Ca2＋/calmodulin signaling system.Plasma and tonoplast membrane Ca2＋-ATPase are of major physiological importance to expel Ca2＋ from eukaryotic cells and to maintain overall Ca2＋ homoeostasis by enhancing their activities and gene expression.
出处
《植物营养与肥料学报》
CAS
CSCD
北大核心
2011年第2期425-432,共8页
Journal of Plant Nutrition and Fertilizers
基金
国家自然科学基金项目(30771250)资助
