Pantoea species (Pantoea spp.) is a diverse group of Gram-negative bacteria in the Enterobacteriaceae family that leads to devastating diseases in rice plants, thus affecting significant economic losses of rice production worldwide. Most critical rice diseases such as grain discoloration, bacterial leaf blight, stem necrosis and inhibition of seed germination have been reported to be caused by this pathogen. To date, 20 Pantoea spp. have been identified and recognized as having similar phenotypic and diverse characteristics. Detection via phenotypic and molecular-based approaches, for example the polymerase chain reaction (PCR) and multiplex PCR give us a better understanding of the diversity of Pantoea genus and helps to improve effective disease control strategies against this emergent bacterial pathogen of rice. In this review, we focused on the significance of rice diseases caused by Pantoea spp. and insights on the taxonomy and characteristics of this destructive pathogen via phenotypic and molecular identification.

Strawberry leaves showing leaf blight symptoms were collected from six different farms in Ismailia and Beheira Governorates in Egypt during the 2020–2021 growing season. Eight bacterial isolates, i.e., Pa₁, Pa₂, Pa₃, Pa₄ (Ismailia farms) and Pa₅, Pa₆, Pa₇ and Pa₈ (Beheira farms) were isolated. A pathogenicity test of bacterial isolates was carried out using detached strawberry leaf technique. All bacterial isolates produced leaf blight disease symptoms. Isolates Pa₂ and Pa₆ showed the highest pathogenic characteristics with clear symptoms on detached strawberry leaves. The phenotypic, biochemical and physiological characters of the highest pathogenic isolates were confirmed by PCR analysis using 16S rRNA gene. The two bacterial isolates were identified as Pantoea ananatis with similarity of 97.05% with accession number MH_127816.1 (isolate Pa₂, Ismailia), while the isolate ( Pa₆, Beheira) with similarity of 97.03% with accession number NR_026045.1. The 16S rDNA sequences were deposited in the GenBank nucleotide databases under accession numbers OM258167 and OM279507, respectively. According to the pathogenicity test, morphological and physiological characteristics as well as molecular data (16S rRNA sequencing analysis), this finding is the first report of P. ananatis as a causal agent of strawberry leaf blight disease in Egypt.