During germination, the spore produces specialized infectious structures called appressorium
that infect aerial tissues.
Research progress on the mechanism of the appressorium
formation between Metarhizium anisopliae conidia and host.
Wuheshi and its nuclear behavior in process of appressorium
Hyphae also can grow from one vessel member to another through perforated end walls as well as directly through secondary wall material by using an appressorium
The proteins identified as exclusive to the conidia were involved in protective processes, appressorium
formation, and the degradation of the host cuticle and exclusive proteins to mycelia were involved in biosynthetic and energy-generating metabolic processes, such as UTPglucose-1-phosphate uridylyltransferase and heatshock protein 70.
On the basis of above findings, it may be speculated that the directly penetrating spores through appressorium
enables spore penetration and once the penetration occurs the spore firmly attached with the cuticle and cannot be removed by allogrooming.
The disease cycle begins with conidia contacting and adhering to the integument of the host (Figure 1), followed by germination, appressorium
production (Figure 2a) or without appressorium
formation (Figure 2b), penetration (Figure 3a,b), development in the hemocoel with the dimorphic (yeast-like forms) stage represented by the formation of short, thick and septated hyphal bodies, mostly with one or more septation (Figure 3a), to mycelial exteriorisation (Figure 4a,b) and as shown (Figure 6 a,b) on pupae mycelial exteriorisation and conidiogenesis on the carcass.
1c), followed by production of an appressorium
Effect of chemical substances associated with the surfaces of plant leaves on appressorium
formation by Colletotrichum acutatum.
Some hyphae were also seen forming what appear to be an appressorium
Occasionally a germ tube or immature appressorium
is observed which suggests that f urther study is warranted.
This structure, called an appressorium
, then produces the probes that penetrate the plant tissue.