香蕉MaASR1基因的抗干旱作用

The Role of Banana MaASR1 in Drought Stress Tolerance

ASR(ABA,stress,ripening induced protein)是一类响应植物干旱胁迫的关键转录因子,在许多植物中已有报道,然而尚未见香蕉(Musa acuminata)中ASR与抗旱作用的相关研究。该实验从香蕉果实cDNA文库中筛选出1个ASR基因,即MaASR1(登录号为AY628102)。干旱胁迫下,该基因在叶片中的表达量高于根部。将MaASR1转入拟南芥(Arabidopsis thaliana),Southern检测确定了两株独立表达的转基因株系(命名为L14和L38)。表型观察发现,此两转基因株系的叶片变小且变厚;Northern和Western检测结果表明,MaASR1在L14和L38中表达。控水处理后,L14和L38的存活率及脯氨酸含量均高于野生型。经干旱胁迫和外源ABA处理后,对MaASR1转基因株系中ABA/胁迫响应基因的表达分析,发现MaASR1可增强转基因株系对ABA信号的敏感度,但不能增强植株依赖于ABA途径的抗旱性。

ASR(abscisic acid [ABA], stress, ripening-induced) proteins are a class of transcriptional factors involved in drought stress tolerance in many plant species. However, the regulation mechanism of ASR in banana under drought stress tolerance is not known. Previously, we screened a new ASR gene from the cDNA library of banana(Musa acuminata cv. ‘Brazilian'), designated MaASR1(accession no. AY628102). MaASR1 expression was higher in leaves than roots under drought stress. MaASR1 was transferred into Arabidopsis thaliana and two independent transgenic lines(L14, L38) were obtained. The leaves of MaASR1 transgenic lines were smaller and thicker than those of the wild type. Survival rate and proline content were higher in L14 and L38 than in the wild type after drought treatment. Under drought stress and ABA treatment, We found that MaASR1 could enhance the sensitivity of the transgenic plants to ABA signal but did not improve ABA-dependent drought stress tolerance.