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.

In the spring of 2019, many plants, mainly winter wheat, were observed to have dwarfism and leaf yellowing symptoms. These plants from several regions of Poland were collected and sent to the Plant Disease Clinic of the Institute of Plant Protection – National Research Institute in Poznań to test for the presence of viral diseases. Double antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA) results showed numerous cases of Wheat dwarf virus (WDV) and a few cases of plant infections caused by Barley yellow dwarf viruses (BYDVs). WDV was detected in 163 out of 236 tested winter wheat plants (69.1%), in 10 out of 27 tested winter barley plants (37%) and in 6 out of 7 triticale plants (85.7%) while BYDVs were found, respectively, in 9.7% (23 out of 236) and in 18.5% (5 out of 27) of tested winter forms of wheat and barley plants. Infected plants came mainly from the regions of Lower Silesia and Greater Poland. Furthermore, individual cases of infections were also confirmed in the following districts: Lubusz, Opole, Silesia, Kuyavia-Pomerania and Warmia-Masuria. Results of Duplex-immunocapture-polymerase chain reaction (Duplex-IC-PCR) indicated the dominance of WDV-W form in wheat and WDV-B form in barley plants. Moreover, results of reverse transcription – polymerase chain reaction (RT-PCR) connected with restriction fragment length polymorphism (RFLP) analysis, performed for 17 BYDVs samples, revealed 8 BYDV-PAS, 4 BYDV-MAV and 2 BYDVPAV as well as the presence of two mixed infections of BYDV-MAV/-PAS and one case of BYDV-MAV/-PAV. Next, RT-PCR reactions confirmed single BYDV-GAV infection and the common presence of BYDV-SGV. To the best of our knowledge, in 2020 the viruses were not a big threat to cereal crops in Poland.