In:
Molecular Plant-Microbe Interactions®, Scientific Societies, Vol. 27, No. 9 ( 2014-09), p. 996-1004
Abstract:
Magnaporthe oryzae forms a highly specialized infection structure called an appressorium for plant penetration. In M. oryzae and many other plant-pathogenic fungi, surface attachment and surface recognition are two essential requirements for appressorium formation. Development of appressoria in the air has not been reported. In this study, we found that expression of a dominant active MoRAS2 G18V allele in M. oryzae resulted in the formation of morphologically abnormal appressoria on nonconducive surfaces, in liquid suspensions, and on aerial hyphae without attachment to hard surfaces. Both the Pmk1 mitogen-activated protein kinase cascade and cAMP signaling pathways that regulate surface recognition and appressorium morphogenesis in M. oryzae were overactivated in the MoRAS2 G18V transformant. In mutants deleted of PMK1 or CPKA, expression of MoRAS2 G18V had no significant effects on appressorium morphogenesis. Furthermore, expression of dominant MoRAS2 in Colletotrichum graminicola and C. gloeosporioides also caused the formation of appressorium-like structures in aerial hyphae. Overall, our data indicate that MoRas2 functions upstream from both the cAMP-PKA and Pmk1 pathways and overactive Ras signaling leads to improper activation of these two pathways and appressorium formation without surface attachment in appressorium-forming pathogens.
Type of Medium:
Online Resource
ISSN:
0894-0282
,
1943-7706
DOI:
10.1094/MPMI-02-14-0052-R
Language:
English
Publisher:
Scientific Societies
Publication Date:
2014
detail.hit.zdb_id:
2037108-1
SSG:
12
