An invasive fungal pathogen has reduced the American chestnut (Castanea dentata), once a keystone tree species within its natural range in the eastern United States and Canada, to functional extinction. To help restore this important canopy tree, blight-tolerant American chestnut trees have been developed using an oxalate oxidase-encoding gene from wheat. This enzyme breaks down oxalate, which is produced by the pathogen and forms killing cankers. Expressing oxalate oxidase results in blight tolerance, where the tree and the fungus can coexist, which is a more evolutionarily stable relationship than direct pathogen resistance. Genetic engineering (GE) typically makes a very small change in the tree's genome, potentially avoiding incompatible gene interactions that have been detected in some chestnut hybrids. The GE American chestnut also retains all the wild American chestnut's alleles for habitat adaptation, which are important for a forest ecosystem restoration program.

中文翻译：

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开发耐枯萎病的美国板栗树。

一种侵入性真菌病原体使美洲板栗 (Castanea dentata) 曾经是美国东部和加拿大自然分布范围内的主要树种，现已功能性灭绝。为了帮助恢复这种重要的树冠树，已经使用小麦中的草酸氧化酶编码基因开发了耐枯病的美国板栗树。这种酶分解由病原体产生的草酸盐，并形成致命的溃疡病。表达草酸氧化酶导致枯萎病耐受性，树木和真菌可以共存，这是一种比直接病原体抗性更稳定的进化关系。基因工程 (GE) 通常会对树的基因组进行非常小的改变，从而可能避免在某些板栗杂交种中检测到的不相容的基因相互作用。