The phytoplasmas attacking the tomato cause various symptoms on the aerial organs, young and growing, of this nightshade. In France, they often appear during the month of July, or even early August. From this period, the growth of affected plants is often slowed down . The apices form shorter internodes and smaller leaves, sometimes rolled up. The lamina tissues are often thicker and even brittle (Figures 1 to 3).

The leaves , in addition to being deformed, also present various color anomalies ; they are more or less yellow (yellows) (figures 4 to 8) and / or purplish (anthocyanins) (figures 9 to 11). Adventitious roots sometimes appear on the stems. Plants infected early on have a rather bushy habit, partly linked to the development of numerous axillaries.

The flowers are particularly affected . Abnormally straightened, they are often sterile or reveal all kinds of morphological aberrations (figures 12 to 14) varying according to the strain and whether or not they were formed at the time of infection:
- the sepals, whose veins take on a purplish color, remain completely joined and the calyx is enlarged (big bud);
- the flowers are sterile and the petals are green, with stamens of the same color (loss of floral pigment, virescence);
- the sepals may be leafy (phyllody); one can also note the malformation or the absence of petals, stamens and carpels, hyperdevelopment of the petioles, etc. ;
- Intense proliferations are observed in plants infected with phytoplasmas of the 16SrVI group.

The rare fruits formed see their growth reduced ; they are dense, color slowly and irregularly and have a rather thick peduncle contrasting with their reduced size fruits.