Arbascules from mycorrhiza related to fungi

2. Name: sajjad ali
M.sc final morning
Session 2018-20
University of peshawar

3. ARBASCULES

4. Arbuscules
Arbuscules are infolding branched haustoria that
formed within a root cortex cell. They were named by
Gallaud (1905),
Arbuscules are originated from Intraradical Hyphae
(IH) and are formed within the root cortex cell. They
can occur sporadically along the roots, but in some
cases arbuscules may occur growing nearly from an
entry point (Schüßler and Walker 2010 )
‘In botany and mycology, a haustorium is a rootlike structure or a structure
that grows into or around another structure to absorb water or nutrients,

5. Arbuscule of Gigaspora margarita with an
elongated trunk hypha (T) and tufts of
fine branch hyphae (arrows)

6. Developing arbuscule of Glomus mosseae in a root cell with
fine branch hyphae (arrows). The trunk (T) of this arbuscule
branched from an intercellular hyphae

7. Arbuscules can assume one of
two types of colonization
patterns: (Two distinct
morphological types)
1) Arum type (Linear AMF)
2) Paris type (Coiling AMF)

8. 1)Arum type (Linear AMF)
In the Arum-type , the fungi form longitudinal
intercellular hyphae in the air spaces between the
cortical cells.
The intercellular hyphae then form short side
branches which penetrate cortical cells to form
arbascule.
In some Arum type AM , hyphal coils are formed
within the passage cells of the hypodermis.
However these coils do not usually make up a large
component of the intracellular fungal biomass
(Smith & Read, 1997).

9. 2) Paris type (Coiling AMF)
In the paris type the intercellular phase of colonization is
absent , or virtually
so instead the paris type is characterized by the formation of
extensive intracellular hyphal coils and arbasculate coils in the
root cortex , spreading directly from cell to cell (Gallud 1905).
The arbasculate coils are similar to hyphal coils , except that
they have small highly branched arbascule like structures
(Gallud ,1905 : Yawney and Schultz ,1990 ).
As with the Arum type entry coils can also be formed in the
hypodermis of roots of Paris type AM (Gallud,1905).

10. a) Arum-type AM b) Paris-type AM

11. Arbuscules formation process

12. Arbascule formation process
Their formation occurs 2 days after root
colonization, i.e. , during the symbiotic
phase and hyphal growth (Brundrett et al.
1985) ,
but in host-plant bioassays, they require a
longer period of time compared to other
structures (Walker 1983 ).
Another distinctive characteristic of the
arbuscule is their limited life time, they
begin to collapse after a few days, but
hyphae and vesicles can remain in roots for
months or even years (Brundrett et al.1985 )

13. Under greenhouse conditions, host
plants colonized by species of
Gigasporaceae begin to show
arbuscules after the third month of
inoculation (Walker 1983 ).
In species of the Order Glomerales
their formation occurs between the
second and third month after
inoculation (Oehl et al. 2008) .

14. Arbuscules morphology also differs among
AMF species. We can observe arbuscules
like an intracellular winding (e.g.,
Scutellospora ) ,
“clouds” format (e.g., Glomus) , or
staining weakly in the presence of acid
reagents (e.g., Acaulospora and
Paraglomus ) (Schüßler and Walker 2010 )

15. Life Quote
You can't go back and
change the beginning, but
you can start where you
are and change the
ending.”