Table 3. Definitions for the nine high-level phenotype outcomes used in PHI-base.

High-level phenotype outcomea	Definition
Loss of pathogenicity	The transgenic strain fails to cause disease that is observed in the wild type (i.e. qualitative effect).
Reduced virulence	The transgenic strain still causes some disease formation but fewer symptoms than the wild-type strain (i.e. a quantitative effect). Synonymous with the term reduced aggressiveness.
Unaffected pathogenicity	The transgenic strain which expresses altered levels of a specific gene product(s) causes the same level of disease compared to the wild-type reference strain.
Increased virulence (Hypervirulence)	The transgenic strain causes greater incidence or severity of disease than the wild-type strain.
Effector (plant avirulence determinant)	Some effector genes are required to cause disease on susceptible hosts but most are not. A plant pathogen-specific term which was previously referred to as a corresponding avirulence (Avr) gene. An effector gene is formally identified because its presence leads to the direct or indirect recognition of a pathogen in resistant host genotypes which possess the corresponding disease resistance (R) gene. Positive recognition leads to activation of plant defense and the pathogen either fails to cause disease or causes less disease. In the absence of the pathogen, effector delivery into a healthy plant possessing the corresponding R gene activates plant defense responses.
Lethal	The transgenic strain is not viable. The gene product is essential for life of the organism.
Enhanced antagonism	The transgenic strain shows greater endophytic biomass in the host and/or the formation of visible disease symptoms.
Resistant to chemical	The transgenic strainb grows and/or develops normally when exposed to chemistry concentrations that are detrimental to the wild-type strain.
Sensitive to chemical	The transgenic strain which expresses either no or reduced levels of a specific gene product(s) or possesses a specific gene mutation(s), has the same abilityc as the wild-type strain to grow and develop when exposed to detrimental chemistry concentrations.

^aCompared to wild-type reference strain (i.e. a direct isogenic strain comparison).

^bMolecular studies on natural field isolate population are also considered, once the natural target site has been identified.

^cOn rare occasions increased sensitivity to chemistry has been observed.