Thus, diversification of antimicrobial effectors by accumulation of multiple variations around an originally unique form may provide significant means of acquiring microbial target specificity [ 11], concerned in the evolutionary arms race between pathogens and their hosts.
Introduction and accumulation of substitution mutations into a duplicated EPIYA segment may then endow altered target-binding specificities, which could generate functional diversification of bacterial EPIYA effectors (Fig. 2B).
Subsequent diversification yielded a diverse palette of effector functions.
However, TE activity has also benefited powdery mildews and other eukaryotic pathogens, favoring the expansion and diversification of a broad repertoire of effector genes, as previously shown [ 31– 31].
Diversification and amplification of this family of effector genes most likely happened as a result of strong natural selection by the host.
It remains to be elucidated whether Taphrina utilize this region as the hotbeds for genomic innovation against plant immune response and the rapid diversification of secreted proteins as effectors that deals with specific hosts.
In Lmb, as in other phytopathogens, the hosting of effector genes in TE-rich genome environment contributed to sequence diversification and probably adaptation to new hosts or better adaptation to the existing host.
Finally, the use of ubiquitylated and sumoylated PCNA as an interaction platform for multiple different PTM-specific effectors indicates a diversification of functions in metazoans.
Apart from preserved conserved regions and motifs typical of Rab family, Rab7/Rab9 proteins have non-conserved sequences and structural features, that may be responsible for diversification of their functions and interactions with effectors and regulators.
In fact, avirulence proteins recognition by plant resistance proteins imposes selection against effector function, and pathogen effector proteins probably overcome resistance through diversification of the genes encoding them [ 30].
