School of Agricultural, Forest, and Environmental Sciences, Clemson University, SC 29634, USA.
Phytopathology. 2012 Aug;102(8):804-11. doi: 10.1094/PHYTO-12-11-0336.
We identified and characterized a β-1,4-endoglucanase, Afr-ENG-1, in the foliar nematode Aphelenchoides fragariae that is differentially expressed when the nematode feeds on fungi or plants. When individuals from hosta plants were transferred to a fungus culture, expression of the enzyme decreased 1,812-fold after five generations on the fungus diet. Afr-eng-1 was readily detected in the genome of 75% of nematodes from the plant population but only in 38% of the diet-changed population. The gene cannot be detected in nematodes maintained on fungus for over 100 generations. Diet was also associated with changes in nematode body size and in the severity of symptoms caused on hosta leaves. Plant-diet nematodes caused larger lesions and were longer and thinner than fungus-diet nematodes. Nematodes moved from a plant diet to a fungus diet for five generations had the same body size as the nematodes that had fed on the fungus for 100 generations. Full-length sequences of Afr-eng-1 were obtained and found to encode a glycosyl hydrolase family 5 protein. This is the first β-1,4-endoglucanase and plant-parasitism-related gene described in the genus Aphelenchoides.
我们在草莓叶甲线虫中鉴定并描述了一种β-1,4-内切葡聚糖酶，Afr-ENG-1，当线虫以真菌或植物为食时，该酶的表达存在差异。当来自玉簪植物的个体转移到真菌培养物中时，在用真菌喂养的第五代后，该酶的表达下降了 1,812 倍。Afr-eng-1 在植物种群中 75%的线虫基因组中很容易检测到，但在改变饮食的种群中仅占 38%。该基因在以真菌维持超过 100 代的线虫中无法检测到。饮食也与线虫体型变化和对玉簪叶片引起的症状严重程度有关。以植物为食的线虫引起的损伤更大，且比以真菌为食的线虫更长、更细。从植物饮食转为真菌饮食喂养五代的线虫，其体型与以真菌喂养 100 代的线虫相同。获得了 Afr-eng-1 的全长序列，并发现其编码一个糖苷水解酶家族 5 蛋白。这是在草莓叶甲属中描述的第一个β-1,4-内切葡聚糖酶和与植物寄生相关的基因。
