洪克前 谷会 陈丽

摘  要：为了探究香蕉MaWRKY1转录因子在抗冷诱导过程中的作用，采用外源过氧化氢（H2O2）、茉莉酸甲酯（MeJA）、水杨酸（SA）和丙烯（propylene）等处理香蕉果实，同时采用外源H2O2、MeJA和脱落酸（ABA）等处理香蕉幼苗，处理结束后，将实验材料放置于7 ℃下贮藏，通过Northern blot技术分析实验材料中MaWRKY1基因表达变化。H2O2、MeJA、SA和propylene等处理均使果实冷害症状推迟2 d出现;处理组果实中MaWRKY1 mRNA积累均早且高于对照组。H2O2、MeJA和ABA等處理也均使幼苗推迟18 h显现冷害症状;处理组幼苗中MaWRKY1基因表达提前且表达量相对较高。相比较这几种外源性调节剂，MeJA和H2O2处理的香蕉果实和幼苗所获得的抗冷效果优于其他生长调节剂，同时MaWRKY1基因表达水平也比其他处理组提前或表达量更高，推测MaWRKY1可能更加积极响应MeJA或H2O2诱导香蕉耐冷性

关键词：香蕉;WRKY1;转录因子;耐冷性

Abstract： To investigate the role of MaWRKY1 in induction of chilling resistance of the banana， fruits were treated with H2O2， MeJA， SA and propylene， respectively， and seedlings were treated with H2O2， MeJA and ABA， respectively. Following treatments， fruits and seedlings were stored at 7 ℃. Northern blot technique was adopted to analyze the changes of MaWRKY1 in fruits and seedlings inducted by chilling resistance. The results indicated that H2O2， MeJA， SA， and propylene treatments delayed the occurrence of chilling injury symptom of fruits by 2 d at 7 ℃. MaWRKY1 mRNA accumulation in the treated fruits was earlier and higher than that of the untreated. The treatment of H2O2， MeJA， and ABA retarded the occurrence of chilling injury symptom of seedlings by 18 h at 7 ℃. In addition， MaWRKY1 mRNA accumulation level was significantly earlier and higher in the treated seedlings than that of the untreated. Compared with other exogenous growth regulators， fruits and seedlings treated with MeJA， and H2O2， respectively had a better chilling resistance， and the MaWRKY1 gene expression was earlier or higher than that in other treated groups， MaWRKY1 might be more active in chilling resistance of banana fruits and seedlings inducted by MeJA or H2O2.

Keywords： banana; WRKY1; transcription factor; chilling resistance

香蕉（Musa acuminate）是世界主要水果之一，经济价值很高，也是我国华南地区北运和出口的主要水果[1-2]。香蕉是典型的呼吸跃变型果实，常温下贮藏一周左右即出现呼吸高峰，导致果实迅速成熟软化并缩短其贮藏期和货架期。低温贮藏可有效地抑制香蕉果实的成熟软化，延长其贮藏寿命，但香蕉果实对低温极其敏感，在温度低于11 ℃时，即发生冷害，严重影响果实的商品价值[3]。施用植物生长调节剂如水杨酸（SA）、茉莉酸甲酯（MeJA）、丙烯（propylene，乙烯功能类似物）、脱落酸（ABA）和过氧化氢（H2O2）等均可提高采后香蕉果实的抗冷性[4-7]，其中许多基因包括MYC、bHLH、PAL、EPX和WRKY等参与了香蕉果实耐冷过程[6-9]。

抗冷反应的转录因子中，WRKY是植物特有的一类转录因子家族。……