Apoga Dace, Barnard John, Craighead Harold G, Hoch Harvey C
Department of Plant Pathology, Cornell University, New York State Agricultural Experiment Station, Geneva, NY 14456, USA.
Fungal Genet Biol. 2004 Jan;41(1):1-12. doi: 10.1016/j.fgb.2003.10.001.
Colletotrichum graminicola, like many plant pathogenic fungi develop appressoria on germling apices, to facilitate penetration of their host. Induction of these structures occurs after contact with the host surface has been established by the germling. Surface contact and subsequent development of appressoria by germlings of C. graminicola was assessed using interference-reflection microscopy (IRM) and microfabricated pillared silicon substrata. Observations with IRM revealed that under low nutrient conditions, 90% of the germlings developed appressoria once they established 4.5 microm of continuous contact with the substratum. Substrata bearing pillars < or =5 microm in width supported < or =10% appressoria; however, as pillar width was increased the percentage of appressoria formed increased in a sigmoid fashion to a maximum of 80%. The percentage of appressoria produced experimentally on these surfaces was compared to data sets generated from a model designed to calculate the probability of appressorium development on similar pillar arrays at various germ tube contact lengths. These results indicate that germ tubes of C. graminicola require more than 4microm of continuous contact with a hydrophobic substratum for induction of appressoria.
禾谷炭疽菌与许多植物病原真菌一样，在芽管顶端形成附着胞，以利于侵染其寄主。这些结构的诱导发生在芽管与寄主表面建立接触之后。利用干涉反射显微镜（IRM）和微加工柱状硅基质评估了禾谷炭疽菌芽管表面接触及随后附着胞的形成情况。IRM观察表明，在低营养条件下，90%的芽管一旦与基质建立4.5微米的连续接触就会形成附着胞。宽度小于或等于5微米的柱状基质上形成的附着胞小于或等于10%；然而，随着柱状宽度增加，形成的附着胞百分比呈S形增加，最高可达80%。将在这些表面上实验产生的附着胞百分比与通过一个模型生成的数据集进行比较，该模型用于计算在不同芽管接触长度下，在类似柱状阵列上附着胞形成的概率。这些结果表明，禾谷炭疽菌的芽管需要与疏水基质连续接触超过4微米才能诱导附着胞的形成。
