脱落酸对甜椒幼苗抗寒性的诱导效应及其机理研究  

Inducing Effects and Its Biological Mechanisms of ABA on the Chilling Resistance of Sweet Pepper Seedlings

作　　者：罗立津[1,2] 徐福乐 翁华钦 洪淑珠 段留生[1] 李召虎[1] 

机构地区：[1]中国农业大学农学与生物技术学院/植物生长调节剂教育部工程研究中心,北京100094 [2]福建超大现代农业科技研究所,福州350003

出　　处：《西北植物学报》2011年第1期94-100,共7页Acta Botanica Boreali-Occidentalia Sinica

基　　金：国家高技术研究发展计划("863"计划)(2006AA10A213)

摘　　要：以砂培甜椒幼苗为材料,先用不同浓度脱落酸(ABA)进行灌根处理,再分两组分别于常温(25℃～30℃)生长7 d(常温苗)或低温驯化(10℃～15℃)30 d(驯化苗)之后进行低温胁迫(5℃)处理,分析幼苗的生长状况及其细胞质膜伤害、渗透调节物质、活性氧清除系统、内源激素的变化特征,以探讨脱落酸对甜椒抗寒性的诱导效应及机理.结果显示,(1)各浓度ABA对甜椒常温苗和驯化苗的株高、茎重均无显著影响,但显著促进驯化苗的侧根生长,在低温胁迫下,显著降低驯化苗叶片的呼吸速率;(2)常温苗的相对电导率仅在10 mg/L ABA处理中比对照显著降低,而驯化苗在各处理浓度下均显著降低,MDA含量表现出与此类似的变化;(3)叶片脯氨酸、可溶性糖、可溶性蛋白、钾离子等渗透调节物质含量在各浓度ABA处理常温苗和驯化苗中均有所增加,但仅脯氨酸含量的增加达到显著水平.(4)各浓度ABA处理都一定程度上提高了常温苗的SOD活性,显著降低了常温苗的CAT和POD活性,H2O2积累量均显著降低,但对于驯化苗,1.0 mg/L和10 mg/L ABA处理却显著降低其SOD活性,POD和CAT活性无显著差异,H2O2积累量也无显著变化.(5)茎尖的ZR、JA-Me含量及IAA/ZR、均与对照无显著差异,但IAA、ABA含量、ABA/ZR比值明显提高,其中1.0和10 mg/L处理的内源ABA含量以及10 mg/L处理的ABA/ZR比值显著高于对照.研究表明,脱落酸能通过降低甜椒幼苗呼吸速率,提高叶片脯氨酸、可溶性糖、钾离子等渗透调节物质以及ABA的积累来诱导增强甜椒幼苗的抗寒性,减少活性氧自由基的产生和累积量,从而减轻低温胁迫造成的伤害,且低温驯化条件下比常温下效果更加明显.To study the inducing effects and biological mechanisms of abscisic acid（ABA） on the chilling resistance of plant,sandy culture method was conducted to examine the effects of ABA on the lipid peroxidation,electrolyte leakage,osmosis-regulating substances,reactive oxygen species,antioxidant enzyme activities and endogenous hormones balance in sweet pepper（Capsicum annuum） seedlings under cold stress.Sweet pepper seedlings were irrigated with 10 mL/plant of 0.10,1.0 or 10 mg/L ABA.The seedlings were grouped and grew under normal temperature（25℃～30℃） for 7 d or domesticated under low temperature（10℃～15℃） for 30 d,and then under cold stress（5℃） for 48 h.Under low temperature,ABA promoted the lateral root growth in the domesticated seedlings and reduced respiration rate,electrolyte leakage and MDA of both the seedlings in domesticated and normal temperature,especially in the domesticated seedlings.The concentration of proline,soluble sugar,potassium in leaf and ABA in stem apex were increased in both the seedlings in domesticated and normal temperature,observably in the proline contents.The superoxide dismutase（SOD） activity and H2O2 contents was increased significantly in the seedlings under normal temperature but decreased in domesticated seedlings;Catalase（CAT） and POD activity were decreased in the seedlings under normal temperature and no change in domesticated seedlings.Contents of IAA,ABA,and value of ABA/ZR were increase observably in both seedlings.As a result,ABA alleviates chilling resistance in sweet pepper seedlings through decreasing respiration rate,and increasing content of proline,soluble sugar,K＋,especially in the domesticated seedlings.

关 键 词：脱落酸(ABA) 甜椒 抗寒性 逆境生理 

分 类 号：Q945.78[生物学—植物学]