不同香蕉品种多聚半乳糖醛酸酶抑制蛋白活性的比较

Comparison of the Activity of Polygalacturonase Inhibiting Proteins in Different Banana Varieties

植物多聚半乳糖醛酸酶抑制蛋白(PGIP)是一种富含亮氨酸重复区域的蛋白质,能够非竞争性地抑制真菌的多聚半乳糖醛酸酶(PG)的活性。以目前生产上几个主要抗枯萎病的香蕉品种为材料,参照Gross的PGIP活性测定方法,通过测定了Musa AAA、Musa ABB、Musa ABB、Musa AA和Musa AAAB等不同细胞基因型的香蕉品种的PGIP活性,发现东莞大蕉(Musa ABB)的活性最高。通过对东莞大蕉根、假茎、叶不同部位的PGIP活性比较,发现假茎的活性最高。用香蕉枯萎病菌4号生理小种接种诱导东莞大蕉能明显提高PGIP活性,观察还发现东莞大蕉苗期PGIP的活性明显高于后期。

Polygalacturonase inhibiting proteins （PGIP）, containing rich leucine with repeated region, can inhibit the activity of a variety of fungal Polygalacturonases （PG）, and is considered as a kind of important factor in plant resistance against fungal infection. In this study, we used several banana varieties as the research materials to detect their PGIP activities to inhibit PGs produced by race 4 of Fusarium oxysporum f.sp. cubense （Foc4）, the severe disease pathogen of banana fusarium wilt. Those banana varieties were concerned as resistant varieties to the pathogen and with different cell genotypes, including Musa AAA, Musa ABB, Musa ABB, Musa AA and Musa AAAB. The results showed that PGIP from Dongguandajiao （Musa ABB） inhibitted PGs of Foc4 with the highest activity among these banana varieties. By comparing the PGIP activities in roots, pseudo-stems and leaves of Dongguandajiao, PGIP from pseudo-stem was found with the highest PGIP activity. The study also found that the PGIP activity could be induced by Foc4 inoculation, and PGIP activity was higher in young seedlings than that in older ones.