Synergistic activity of endochitinase and exochitinase from Trichoderma atroviride (T-harzianum) against the pathogenic fungus (Venturia inaequalis) in transgenic apple plants
Synergistic activity of endochitinase and exochitinase from Trichoderma atroviride (T-harzianum) against the pathogenic fungus (Venturia inaequalis) in transgenic apple plants
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DOI：
10.1023/a:1013036732691
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发表时间：
2001-12-01
影响因子：
3
通讯作者：
Aldwinckle, HS
中科院分区：
文献类型：
--
作者：
Bolar, JP;Norelli, JL;Aldwinckle, HS
将编码抗真菌蛋白内切几丁质酶或外切几丁质酶（N-乙酰基-β-D-己糖胺酶）的生物防治真菌深绿色木霉的基因单独或组合插入“Marshall McIntosh”苹果中。这些基因由经过修饰的 CaMV35S 启动子驱动。筛选所得植物对苹果黑星病病原文丘里菌（Venturia inaequalis）的抗性，以及酶表达对生长的影响。当单独表达时，抗病性与任一酶的表达水平相关，但外切壳多糖酶不如内切壳多糖酶有效。内切几丁质酶的表达水平与植物生长呈负相关，而外切几丁质酶对此特性没有一致的影响。同时表达两种酶的植物比以相同水平表达任一单一酶的植物具有更强的抗性；分析表明，这两种酶具有协同作用，可以减少疾病。选定的品系，尤其是表达低水平内切几丁质酶活性和中等水平外切几丁质酶活性的品系，在生长室试验中具有高度抗性，并且相对于对照植物活力的降低可以忽略不计。我们相信，这是关于植物中由N-乙酰己糖胺酶的表达诱导的抗性的第一份报告，并且是关于外切壳多糖酶和内切壳多糖酶之间的植物内协同作用的第一份报告。
Genes from the biocontrol fungus Trichoderma atroviride encoding the antifungal proteins endochitinase or exochitinase (N-acetyl-beta -D-hexosaminidase) were inserted into 'Marshall McIntosh' apple singly and in combination. The genes were driven by a modified CaMV35S promoter. The resulting plants were screened for resistance to Venturia inaequalis, the causal agent of apple scab, and for effects of enzyme expression on growth. Disease resistance was correlated with the level of expression of either enzyme when expressed alone but exochitinase was less effective than endochitinase. The level of expression of endochitinase was negatively correlated with plant growth while exochitinase had no consistent effect on this character. Plants expressing both enzymes simultaneously were more resistant than plants expressing either single enzyme at the same level; analyses indicated that the two enzymes acted synergistically to reduce disease. Selected lines, especially one expressing low levels of endochitinase activity and moderate levels of exochitinase activity, were highly resistant in growth chamber trials and had negligible reduction in vigor relative to control plants. We believe that this is the first report of resistance in plants induced by expression of an N-acetylhexosaminidase and is the first report of in planta synergy between an exochitinase and an endochitinase.